Endless belt, fixing belt, fixing device, and image forming apparatus

Abstract

To provide an endless belt that is excellent in all of insulating property, thermal conductivity in a circumferential direction, and bending durability.SOLUTION: An endless belt includes resin, and an acicular filler that has a thermal conductivity of 220 W / mK or more and 320 W / mK or less and a volume resistivity of 1011 Ωcm or more and 1016 Ωcm or less, and is contained in the endless belt in an amount of 1 mass% or more and 30 mass% or less.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an endless belt, a fixing belt, a fixing device, and an image forming apparatus. [Background technology]

[0002] Patent Document 1 discloses a thermally conductive seamless belt that is a polyimide tubular body containing thermally conductive inorganic fine powder, the thermally conductive inorganic fine powder being spherical aluminum nitride, and the content of the thermally conductive inorganic powder relative to 100 parts by weight of polyimide resin being in the range of 10 to 40 parts by weight. Patent Document 2 discloses a transfer-fixing belt having a substrate layer made of a polyimide resin composition containing component A: thermally conductive inorganic filler powder, component B: conductive powder, and component C: fluororesin powder. Furthermore, Patent Document 3 discloses an insulating and thermally conductive polyimide resin composition containing a polyimide resin and an insulating and thermally conductive filler made of aluminum nitride or aluminum nitride whose surface is coated with aluminum oxide. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-17720 [Patent Document 2] Japanese Patent Application Laid-Open No. 2006-259248 [Patent Document 3] JP 2016-153500 A Summary of the Invention [Problem to be solved by the invention]

[0004] The object of the present invention is to provide an endless belt including a resin and needle-like fillers, the needle-like fillers having a thermal conductivity of less than 220 W / mK or more than 320 W / mK and a volume resistivity of 10 11 Less than Ωcm or 10 16The object of the present invention is to provide an endless belt that is superior in all of insulation properties, thermal conductivity in the circumferential direction, and bending durability compared to when the content of the endless belt exceeds Ωcm, or when the content of the endless belt is less than 1% by mass or exceeds 30% by mass. [Means for solving the problem]

[0005] Specific means for solving the above problems include the following aspects. <1> Resin and Thermal conductivity is 220W / mK or more and 320W / mK or less, and volume resistivity is 10 11 Ωcm or more 10 16 Ωcm or less, and a needle filler contained in the endless belt in an amount of 1% by mass or more and 30% by mass or less; An endless belt including: <2> The thermal conductivity of the endless belt in the circumferential direction is 0.5 W / mK or more and 3.0 W / mK or less, and the volume resistivity is 10 13 Ωcm or more 10 16 Ωcm or less <1> The endless belt described in

[0006] <3> a resin; and a needle filler whose content relative to the endless belt is 1% by mass or more and 30% by mass or less, Thermal conductivity in the circumferential direction is 0.5W / mK or more and 3.0W / mK or less, and volume resistivity is 10 13 Ωcm or more 10 16 An endless belt with a resistance of less than Ωcm. <4> The needle-like filler has a thermal conductivity of 220 W / mK or more and 320 W / mK or less, and a volume resistivity of 10 11 Ωcm or more 10 16 Ωcm or less <3> The endless belt described in

[0007] <5> The needle-like filler is an aluminum nitride single crystal. <1> ~ <4> 10. The endless belt according to any one of the preceding items. <6> The length of the needle filler is 100 μm or more and 6000 μm or less. <1> ~ <5> 10. The endless belt according to any one of the preceding items. <7> The diameter of the needle-like filler is 1 μm or more and 4 μm or less. <6> The endless belt described in <8> The aspect ratio of the needle filler is 100 or more and 2000 or less. <1> ~ <7> 10. The endless belt according to any one of the preceding items. <9> The needle fillers are oriented in the circumferential direction of the endless belt. <1> ~ <8> 10. The endless belt according to any one of the preceding items. <10> The orientation rate of the needle filler in the circumferential direction of the endless belt is 70% or more. <9> The endless belt described in

[0008] <11> <1> ~ <10> 10. A fixing belt comprising: the endless belt according to any one of 1 to 9; and a surface layer provided on an outer peripheral surface of the endless belt. <12> an elastic layer provided between the endless belt and the surface layer; <11> The fixing belt according to claim 1. <13> The elastic layer has a thermal conductivity of 220 W / mK or more and 320 W / mK or less, a volume resistivity of 10 11 Ωcm or more 10 16 Contains needle-shaped fillers of Ωcm or less <12> The fixing belt according to claim 1. <14> The needle-like filler contained in the elastic layer is aluminum nitride single crystal. <13> The fixing belt according to claim 1.

[0009] <15> <11> ~ <14> a first rotating body formed of the endless belt according to any one of the above items; a second rotor disposed in contact with an outer peripheral surface of the first rotor; a pressing member disposed inside the first rotating body and pressing the first rotating body against the second rotating body from an inner peripheral surface of the first rotating body; A fixing device comprising: <16> an image carrier; a charging device for charging the surface of the image carrier; a latent image forming device for forming a latent image on the charged surface of the image carrier; a developing device that develops the latent image with toner to form a toner image; a transfer device that transfers the toner image onto a recording medium; The toner image is fixed onto a recording medium. <15> a fixing device according to the above; An image forming apparatus comprising: [Effects of the Invention]

[0010] <1> According to the invention, in an endless belt including a resin and a needle-like filler, the needle-like filler has a thermal conductivity of less than 220 W / mK or more than 320 W / mK and a volume resistivity of 10 11 Less than Ωcm or 10 16 The resulting endless belt is superior in insulation, thermal conductivity in the circumferential direction, and bending durability compared to when the content exceeds Ωcm, or when the content relative to the endless belt is less than 1% by mass or more than 30% by mass. <2> According to the invention, the thermal conductivity of the endless belt in the circumferential direction is less than 0.5 W / mK or more than 3.0 W / mK, or the volume resistivity is 10 13 Less than Ωcm or 10 16 Compared to a case where the resistivity exceeds Ωcm, an endless belt is provided which is superior in all respects: insulation, thermal conductivity in the circumferential direction, and bending durability.

[0011] <3> According to the invention, in an endless belt containing a resin and a needle-like filler, the content of the resin and needle-like filler relative to the endless belt is less than 1% by mass or more than 30% by mass, the thermal conductivity in the circumferential direction is less than 0.5 W / mK or more than 3.0 W / mK, or the volume resistivity is 10 13 Less than Ωcm or 10 16 Compared to a case where the resistivity exceeds Ωcm, an endless belt is provided which is superior in all respects: insulation, thermal conductivity in the circumferential direction, and bending durability. <4> According to the invention, the thermal conductivity of the needle-like filler is less than 220 W / mK or more than 320 W / mK, or the volume resistivity is 10 11 Less than Ωcm or 10 16 Compared to a case where the resistivity exceeds Ωcm, an endless belt is provided which is superior in all respects: insulation, thermal conductivity in the circumferential direction, and bending durability.

[0012] <5> According to the invention, an endless belt is provided which is superior in all of insulation properties, thermal conductivity in the circumferential direction, and bending durability compared to when the needle filler is potassium titanate. <6> According to the invention, an endless belt is provided which is superior in insulation properties, thermal conductivity in the circumferential direction, and bending durability compared to when the length of the needle filler is less than 100 μm or exceeds 6000 μm. <7> According to the invention, an endless belt is provided which is superior in insulation properties, thermal conductivity in the circumferential direction, and bending durability compared to when the diameter of the needle filler is less than 1 μm or exceeds 4 μm. <8> According to the invention, an endless belt is provided which is superior in insulation properties, thermal conductivity in the circumferential direction, and bending durability compared to when the aspect ratio of the needle filler is less than 100 or exceeds 2000. <9> According to the invention, an endless belt is provided that has superior thermal conductivity in the circumferential direction compared to a case where the needle fillers are not oriented in the circumferential direction of the endless belt. <10> According to the invention, an endless belt having superior thermal conductivity in the circumferential direction is provided, compared to an endless belt having an orientation rate of needle fillers in the circumferential direction of the endless belt of less than 70%.

[0013] <11> , <12> , <13> , or <14> According to the invention, a resin and a needle-like filler are included, and the needle-like filler has a thermal conductivity of less than 220 W / mK or more than 320 W / mK and a volume resistivity of 10 11 Less than Ωcm or 10 16 The fixing belt has an endless belt that is superior in insulation, thermal conductivity in the circumferential direction, and bending durability compared to an endless belt having a resistivity exceeding Ωcm or a content of less than 1% by mass or more than 30% by mass relative to the endless belt.

[0014] <15> or <16> According to the invention, a resin and a needle-like filler are included, and the needle-like filler has a thermal conductivity of less than 220 W / mK or more than 320 W / mK and a volume resistivity of 10 11 Less than Ωcm or 10 16The present invention provides a fixing device and an image forming apparatus equipped with a fixing belt having an endless belt that is superior in insulation, thermal conductivity in the circumferential direction, and bending durability compared to an endless belt having a resistivity exceeding Ωcm or a content of less than 1% by mass or more than 30% by mass relative to the endless belt. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is a schematic cross-sectional view illustrating an example of a fixing belt according to the present disclosure. [Figure 2] 1 is a schematic configuration diagram illustrating an example of a fixing device according to a first embodiment of the present disclosure. [Figure 3] FIG. 6 is a schematic configuration diagram illustrating an example of a fixing device according to a second embodiment of the present disclosure. [Figure 4] 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0016] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following describes embodiments of the present invention. These descriptions and examples are intended to illustrate the embodiments and are not intended to limit the scope of the embodiments.

[0017] In the present specification, in which numerical ranges are described 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. Furthermore, in the numerical ranges described in this specification, the upper or lower limit of the numerical ranges may be replaced with values ​​shown in the examples.

[0018] In this specification, each component may contain multiple types of corresponding substances. In this specification, when referring to the amount of each component in a composition, if there are multiple substances corresponding to each component in the composition, the amount refers to the total amount of those multiple substances present in the composition, unless otherwise specified.

[0019] In this specification, unless otherwise specified, the term "endless belt according to the present disclosure" refers to both the first and second embodiments described below.

[0020] <First embodiment of endless belt> The first embodiment of the endless belt according to the present disclosure is a composite material including a resin and a material having a thermal conductivity of 220 W / mK or more and 320 W / mK or less and a volume resistivity of 10 11 Ωcm or more 10 16 Ωcm or less, and a needle filler content of 1% by mass or more and 30% by mass or less relative to the endless belt. is. The thermal conductivity is 220W / mK or more and 320W / mK or less, and the volume resistivity is 10 11 Ωcm or more 10 16 Acicular fillers with a resistance of Ωcm or less are also called "specific acicular fillers."

[0021] An endless belt containing resin and granular aluminum nitride is known, but in order to obtain sufficient thermal conductivity (particularly thermal conductivity in the circumferential direction), the content of granular aluminum nitride must be high (for example, 30 mass% or more of the endless belt). If the content of granular aluminum nitride in the endless belt is high, the toughness inherent in the resin may be impaired, and the flexural durability may decrease. On the other hand, in the first embodiment of the endless belt according to the present disclosure, needle-like fillers having high thermal conductivity and high volume resistivity are contained together with the resin in an amount of 1% by mass to 30% by mass based on the endless belt. It is presumed that the physical properties, shape, and content of the needle-like fillers combine to provide an endless belt having excellent thermal conductivity (particularly, thermal conductivity in the circumferential direction) and insulating properties without reducing the bending durability of the endless belt. Hereinafter, unless otherwise specified, the expression "thermal conductivity in an endless belt" or "thermal conductivity of an endless belt" refers to the thermal conductivity in the circumferential direction of the endless belt.

[0022] The specific needle filler and resin used in the endless belt according to the present disclosure will be described below.

[0023] [Specific needle filler] The first embodiment of the endless belt according to the present disclosure has a thermal conductivity of 220 W / mK or more and 320 W / mK or less, a volume resistivity of 10 11 Ωcm or more 10 16 Includes needle-shaped fillers (specific needle-shaped fillers) with a resistance of Ωcm or less.

[0024] The thermal conductivity of the specific needle filler is 220 W / mK or more and 320 W / mK or less, and from the viewpoint of increasing the thermal conductivity of the endless belt, it is preferably 260 W / mK or more and 320 W / mK or less, and more preferably 260 W / mK or more and 300 W / mK or less.

[0025] The thermal conductivity of the specific needle-shaped filler is determined, for example, by converting the thermal diffusivity measured using a thermal diffusivity measuring device (TD-1 HTV manufactured by Advance Riko Co., Ltd.) into thermal conductivity. When measuring the thermal conductivity of the specific needle-shaped filler contained in the endless belt, for example, the components other than the specific needle-shaped filler contained in the endless belt (resin, other additives) are dissolved in a solvent, and the remaining specific needle-shaped filler is subjected to the above measurement.

[0026] The volume resistivity of the specific needle-shaped filler is 10 11 Ωcm or more 10 16 Ωcm or less, and from the viewpoint of improving the insulation properties of the endless belt, 12 Ωcm or more 10 16 It is preferable that the resistance is 10 Ωcm or less. 14 Ωcm or more 10 16 It is more preferable that the resistivity is Ωcm or less.

[0027] The volume resistivity of the specific needle-shaped filler is measured, for example, using a resistivity measuring device (SM7420 manufactured by Hioki E.E. Corporation). When measuring the volume resistivity of the specific needle-shaped filler contained in the endless belt, for example, the components other than the specific needle-shaped filler contained in the endless belt (resin, other additives) are dissolved in a solvent, and the remaining specific needle-shaped filler is subjected to the above measurement.

[0028] From the viewpoint of improving the insulation, thermal conductivity, and flexural durability of the endless belt, the length of the specific needle filler is preferably 100 μm or more and 6000 μm or less, more preferably 1000 μm or more and 5000 μm or less, and even more preferably 2000 μm or more and 4000 μm or less.

[0029] From the viewpoint of improving the insulation, thermal conductivity, and flexural durability of the endless belt, the diameter of the specific needle filler is preferably 1 μm or more and 4 μm or less, more preferably 1.5 μm or more and 3.5 μm or less, and even more preferably 2 μm or more and 3 μm or less. Here, the diameter of the specific needle-like filler means the maximum diameter of the filler.

[0030] From the viewpoint of improving the insulation, thermal conductivity, and flexural durability of the endless belt, the aspect ratio of the specific needle filler is preferably 100 or more and 2000 or less, more preferably 500 or more and 1600 or less, and even more preferably 900 or more and 1200 or less. Here, the aspect ratio of a needle-like filler means the value obtained by dividing the length of the needle-like filler by the diameter of the needle-like filler.

[0031] The length, diameter, and aspect ratio of the needle filler are determined by the following method. That is, 100 needle-like fillers to be measured are observed under an optical microscope, and the length and diameter (corresponding to the width of the needle-like filler when viewed from the side on the image) of each needle-like filler are measured from the obtained observation image, and the aspect ratio is calculated from these values. The arithmetic mean value of the lengths of the 100 needle-like fillers is calculated and used as the length of the needle-like filler. Similarly, the arithmetic mean value of the diameters of the 100 needle-like fillers (specifically, the maximum width of the needle-like filler) is calculated and used as the diameter of the needle-like filler. Furthermore, the arithmetic mean value of the aspect ratios of the 100 needle-like fillers calculated is calculated and used as the aspect ratio of the needle-like filler. When measuring the length, diameter, and aspect ratio of a specific needle-shaped filler contained in an endless belt, for example, components other than the filler contained in the endless belt (resin, other additives) are dissolved in a solvent, and the above measurements and calculations are performed on the remaining specific needle-shaped filler.

[0032] The specific needle filler is preferably aluminum nitride single crystal from the viewpoint of improving the thermal conductivity and insulating properties of the endless belt and also improving the flex durability. Aluminum nitride single crystals have the property of being less reactive with water, and therefore, an endless belt containing aluminum nitride single crystals as the specific needle-like filler is less likely to experience dimensional fluctuations due to moisture absorption, and has excellent dimensional accuracy.

[0033] In the first embodiment of the endless belt according to the present disclosure, the content of the specific needle filler relative to the endless belt (i.e., relative to the total mass of the endless belt) is 1% by mass or more and 30% by mass or less, preferably 3% by mass or more and 25% by mass or less, more preferably 10% by mass or more and 20% by mass or less, and even more preferably 12% by mass or more and 18% by mass or less. Increasing the content of the specific needle-like filler increases the thermal conductivity of the endless belt without reducing the insulating properties of the endless belt, while keeping the content of the specific needle-like filler at 25% by mass or less of the total mass of the belt maintains excellent flexural durability.

[0034] [resin] A first embodiment of an endless belt according to the present disclosure includes a resin. The resin contained in the endless belt according to the first embodiment of the present disclosure is not particularly limited, and a resin may be selected depending on the application of the belt. The resin contained in the first embodiment of the endless belt according to the present disclosure is preferably a heat-resistant resin. Examples of resins include highly heat-resistant and high-strength heat-resistant resins such as polyimide, aromatic polyamide, and liquid crystal materials such as thermotropic liquid crystal polymers. In addition to these, polyester, polyethylene terephthalate, polyethersulfone, polyetherketone, polysulfone, polyimideamide (polyamideimide), etc. are also used. Among these, polyimide is preferred as the resin from the viewpoint of heat resistance, mechanical strength, etc.

[0035] In the first embodiment of the endless belt according to the present disclosure, polyimide, which is a heat-resistant resin, is preferred from the viewpoint of heat resistance. Examples of polyimides include imidized products of polyamic acids (precursors of polyimide resins), which are polymers of tetracarboxylic dianhydrides and diamine compounds.Specific examples of polyimides include resins obtained by polymerizing equimolar amounts of tetracarboxylic dianhydrides and diamine compounds in a solvent to obtain a polyamic acid solution, and then imidizing the polyamic acid.

[0036] The tetracarboxylic dianhydride may be either an aromatic or aliphatic compound, but from the viewpoint of heat resistance, an aromatic compound is preferred.

[0037] Examples of aromatic tetracarboxylic dianhydrides include pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-biphenylsulfonetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 3,3',4,4'-biphenylethertetracarboxylic dianhydride, 3,3',4,4'-dimethyldiphenylsilanetetracarboxylic dianhydride, 3,3',4,4'-tetraphenylsilanetetracarboxylic dianhydride, 1,2,3,4-furantetracarboxylic dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylsulfide dianhydride, 4,4 4,4'-bis(3,4-dicarboxyphenoxy)diphenylsulfone dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride, 3,3',4,4'-perfluoroisopropylidenediphthalic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, bis(phthalic acid)phenylphosphine oxide dianhydride, p-phenylene-bis(triphenylphthalic acid) dianhydride, m-phenylene-bis(triphenylphthalic acid) dianhydride, bis(triphenylphthalic acid)-4,4'-diphenylether dianhydride, bis(triphenylphthalic acid)-4,4'-diphenylmethane dianhydride, and the like.

[0038] Examples of aliphatic tetracarboxylic dianhydrides include butane tetracarboxylic dianhydride, 1,2,3,4-cyclobutane tetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutane tetracarboxylic dianhydride, 1,2,3,4-cyclopentane tetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentyl acetic dianhydride, 3,5,6-tricarboxynorbornane-2-acetic dianhydride, 2,3,4,5-tetrahydrofuran tetracarboxylic dianhydride, 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic dianhydride, bicyclo[2,2,2]-oct-7-ene aliphatic or alicyclic tetracarboxylic acid dianhydrides such as 1,3,3a,4,5,9b-hexahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, 1,3,3a,4,5,9b-hexahydro-5-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione, and 1,3,3a,4,5,9b-hexahydro-8-methyl-5-(tetrahydro-2,5-dioxo-3-furanyl)-naphtho[1,2-c]furan-1,3-dione.

[0039] Among these, the tetracarboxylic acid dianhydride is preferably an aromatic tetracarboxylic acid dianhydride, specifically, for example, pyromellitic acid dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, 2,3,3',4'-biphenyltetracarboxylic acid dianhydride, 3,3',4,4'-biphenylethertetracarboxylic acid dianhydride, 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride, further, pyromellitic acid dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride is more preferable, and 3,3',4,4'-biphenyltetracarboxylic acid dianhydride is particularly preferable.

[0040] The tetracarboxylic dianhydrides may be used alone or in combination of two or more. When two or more tetracarboxylic acid dianhydrides are used in combination, aromatic tetracarboxylic acid dianhydrides or aliphatic tetracarboxylic acid dianhydrides may be used in combination, or an aromatic tetracarboxylic acid dianhydride and an aliphatic tetracarboxylic acid dianhydride may be used in combination.

[0041] On the other hand, the diamine compound is a diamine compound having two amino groups in its molecular structure. The diamine compound may be either an aromatic or aliphatic compound, but is preferably an aromatic compound.

[0042] Examples of the diamine compound include p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylethane, 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, 1,5-diaminonaphthalene, 3,3-dimethyl-4,4'-diaminobiphenyl, 5-amino-1-(4'-aminophenyl)-1,3,3-trimethylindane, 6-amino-1-(4'-aminophenyl)-1,3 ,3-Trimethylindane, 4,4'-diaminobenzanilide, 3,5-diamino-3'-trifluoromethylbenzanilide, 3,5-diamino-4'-trifluoromethylbenzanilide, 3,4'-diaminodiphenyl ether, 2,7-diaminofluorene, 2,2-bis(4-aminophenyl)hexafluoropropane, 4,4'-methylene-bis(2-chloroaniline), 2,2',5,5'-tetrachloro-4,4'-diaminobiphenyl, 2,2'-dichloro-4,4'-diamino-5,5'-dimethicone 4,4'-diamino-2,2'-bis(trifluoromethyl)biphenyl, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]hexafluoropropane, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)-biphenyl, 1,3'-bis(4-aminophenoxy)benzene, 9,9-bis(4-aminophenyl)fluorene aromatic diamines such as 4,4'-(p-phenyleneisopropylidene)bisaniline, 4,4'-(m-phenyleneisopropylidene)bisaniline, 2,2'-bis[4-(4-amino-2-trifluoromethylphenoxy)phenyl]hexafluoropropane, and 4,4'-bis[4-(4-amino-2-trifluoromethyl)phenoxy]-octafluorobiphenyl; aromatic diamines having two amino groups bonded to an aromatic ring and a heteroatom other than the nitrogen atom of the amino groups, such as diaminotetraphenylthiophene;1,1-meta-xylylenediamine, 1,3-propanediamine, tetramethylenediamine, pentamethylenediamine, octamethylenediamine, nonamethylenediamine, 4,4-diaminoheptamethylenediamine, 1,4-diaminocyclohexane, isophoronediamine, tetrahydrodicyclopentadienylenediamine, hexahydro-4,7-methanoindanidinediamine, tricyclo[6,2,1,0; 2.7 ]-undecylenedimethyldiamine, 4,4'-methylenebis(cyclohexylamine), and other aliphatic diamines and alicyclic diamines.

[0043] Among these, the diamine compound is preferably an aromatic diamine compound, specifically, for example, p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, and particularly, 4,4'-diaminodiphenyl ether and p-phenylenediamine are preferred.

[0044] The diamine compounds may be used singly or in combination of two or more. When two or more diamine compounds are used in combination, aromatic diamine compounds or aliphatic diamine compounds may be used in combination, or an aromatic diamine compound and an aliphatic diamine compound may be used in combination.

[0045] Among these, from the viewpoint of heat resistance, aromatic polyimides (specifically, imidized products of polyamic acids (precursors of polyimide resins), which are polymers of aromatic tetracarboxylic dianhydrides and aromatic diamine compounds) are preferred as polyimides. The aromatic polyimide is more preferably a polyimide having a structural unit represented by the following general formula (PI1).

[0046] [ka]

[0047] In the general formula (PI1), R P1 represents a phenyl group or a biphenyl group, and R P2 represents a divalent aromatic group. R P2 Examples of the divalent aromatic group represented by include a phenylene group, a naphthyl group, a biphenyl group, a diphenyl ether group, etc. As the divalent aromatic group, a phenylene group and a biphenyl group are preferred from the viewpoint of flexural durability.

[0048] The number average molecular weight of the polyimide is preferably 5,000 or more and 100,000 or less, more preferably 7,000 or more and 50,000 or less, and even more preferably 10,000 or more and 30,000 or less.

[0049] The number average molecular weight of polyimide is measured by gel permeation chromatography (GPC) under the following measurement conditions. Column: Tosoh TSKgel α-M (7.8 mm ID x 30 cm) Eluent: DMF (dimethylformamide) / 30mM LiBr / 60mM phosphoric acid ·Flow rate: 0.6mL / min ·Injection volume: 60μL Detector: RI (Differential Refractive Index Detector)

[0050] In the first embodiment of the endless belt according to the present disclosure, the resin content is preferably 75% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, and particularly preferably 90% by mass or more, based on the total mass of the belt.

[0051] [Additives] The first embodiment of the endless belt according to the present disclosure may contain, in addition to the specific needle-like filler and resin, well-known additives such as fillers other than the specific needle-like filler and lubricants.

[0052] [Belt properties] In a first embodiment of the endless belt according to the present disclosure, the thermal conductivity in the circumferential direction is 0.5 W / mK or more and 3.0 W / mK or less, and the volume resistance is 10 13 Ωcm or more 10 16 It is preferably Ωcm or less. That is, it is preferable that the endless belt according to the present disclosure itself has the above-mentioned thermal conductivity and volume resistivity.

[0053] (thermal conductivity) As described above, the thermal conductivity in the circumferential direction of the first embodiment of the endless belt according to the present disclosure is preferably 0.5 W / mK or more and 3.0 W / mK or less, more preferably 1.0 W / mK or more and 3.0 W / mK or less, and even more preferably 1.5 W / mK or more and 3.0 W / mK or less.

[0054] The thermal conductivity of the belt is measured as follows. Specifically, a flat test piece is cut from the target belt, and the thermal conductivity is determined from the thermal diffusivity in the thickness direction of the test piece. Specifically, the test piece is placed on the holder of a thermal diffusivity measuring device TD-1 HTV (manufactured by Advance Riko Co., Ltd.), and the thermal diffusivity is measured three times in air. The arithmetic mean of the three measurements is taken as the thermal diffusivity of the belt, and is converted to thermal conductivity from the belt's density and specific heat. The present measuring device and method can measure the thermal conductivity in the axial direction and circumferential direction of the belt in addition to the thickness direction of the belt.

[0055] (volume resistivity) As described above, the first embodiment of the endless belt according to the present disclosure is 13 Ωcm or more 10 16 It is preferable that the resistance is 10 Ωcm or less. 14 Ωcm or more 10 16 It is more preferable that the resistance is 10 Ωcm or less. 15 Ωcm or more 10 16 It is more preferable that the resistivity is Ωcm or less.

[0056] Here, the volume resistivity of the endless belt is measured as follows. A microcurrent meter (R8430A manufactured by Advantest) is used as the resistance measuring device, and a UR probe (manufactured by Mitsubishi Chemical Analytech Co., Ltd.) is used as the probe to measure the volume resistivity (Ωcm) at 18 points in total (6 points at equal intervals around the circumference of the endless belt, and 3 points at the center and both ends in the width direction), at a voltage of 500V, an application time of 10 seconds, and a pressure of 1kgf, and the average value is calculated. The measurements are also performed in an environment of a temperature of 22°C and a humidity of 55%RH.

[0057] (Orientation of needle-like fillers) In the first embodiment of the endless belt according to the present disclosure, the specific needle filler particles are preferably oriented in the circumferential direction of the endless belt. By aligning the specific needle filler particles in the endless belt in the circumferential direction in this manner, the thermal conductivity of the endless belt in the circumferential direction can be increased compared to the thickness direction and the axial direction of the endless belt. From the viewpoint of increasing the thermal conductivity of the endless belt in the circumferential direction, the orientation rate of the specific needle filler in the circumferential direction of the endless belt is preferably 70% or more, more preferably 80% or more, and even more preferably 90% or more. The upper limit of the orientation rate may be 100% or 90%.

[0058] Here, the orientation rate A of the needle filler in the circumferential direction of the endless belt is determined by the following method. That is, when the total number of needle fillers is N and the number of needle fillers for which the inclination θ of the needle fillers in the longitudinal direction relative to the circumferential direction of the endless belt is −30°≦θ≦30° is N', the orientation rate A is expressed by the following formula 1. Equation 1: Orientation rate A = (N' / N) x 100

[0059] When determining the orientation rate A, N, θ, and N′ are measured by the following method. Specifically, the outer peripheral surface of the endless belt is observed with an optical microscope at 10 equally spaced locations from one end to the other in the width direction, and 50 needle-like fillers are extracted, 5 from each location. For all 50 extracted needle-like fillers (i.e., the total number of needle-like fillers N=50), the inclination θ of the needle-like filler in the longitudinal direction with respect to the circumferential direction of the endless belt is measured, and the number N' of needle-like fillers where θ satisfies -30°≦θ≦30° is determined. The determined value is substituted into the above formula 1 to calculate the orientation rate A.

[0060] An example of a method for controlling the orientation rate A within a range is to adjust the coating conditions when producing an endless belt using a flow coating method (also known as a spiral coating method). In the flow coating method, for example, a coating liquid for forming an endless belt is applied to the outer peripheral surface of a cylindrical or columnar substrate from one end to the other in the direction of the substrate's rotation axis (i.e., the width direction of the endless belt) while the substrate is being rotated. In this case, the orientation rate A can be controlled by adjusting the conditions for the moving speed of the coating liquid discharge part in the direction of the rotation axis.

[0061] <Second embodiment of the belt> A second embodiment of an endless belt according to the present disclosure includes a resin and a needle filler whose content relative to the endless belt is 1% by mass or more and 30% by mass or less, and the endless belt has a thermal conductivity of 0.5 W / mK or more and 3.0 W / mK or less in the circumferential direction and a volume resistivity of 10 13 Ωcm or more 10 16 It is an endless belt with a resistance of less than Ωcm. As is clear from the above configuration, the second embodiment of the endless belt according to the present disclosure has high thermal conductivity and insulation in the circumferential direction, and the content of needle-like filler is kept low, so it has excellent bending durability.

[0062] In a second embodiment of the endless belt according to the present disclosure, the thermal conductivity in the circumferential direction is 1.0 W / mK or more and 3.0 W / mK or less, and the volume resistivity is 10 14 Ωcm or more 10 16 It is more preferable that the resistivity is Ωcm or less.

[0063] The second embodiment of the endless belt according to the present disclosure preferably includes a resin and a specific needle-like filler, similar to the first embodiment of the endless belt according to the present disclosure. That is, the needle-like filler in the second embodiment of the endless belt according to the present disclosure is preferably the specific needle-like filler. The resin and needle-like filler (preferably the specific needle-like filler) in the second embodiment are the same as those in the preferred aspects of the first embodiment. The endless belt according to the second embodiment of the present disclosure may also contain well-known additives. Furthermore, in the second embodiment of the endless belt according to the present disclosure, the needle-like filler (preferably the specific needle-like filler) is preferably oriented in the circumferential direction of the endless belt, and the orientation rate A is preferably 70% or more, more preferably 80% or more, and even more preferably 90% or more. The upper limit of the orientation rate may be 100% or 90%.

[0064] [Belt shape] The diameter, width, and thickness of the endless belt according to the present disclosure may be determined appropriately depending on the application.

[0065] The film thickness of the endless belt according to the present disclosure is, for example, 50 μm to 600 μm, preferably 50 μm to 500 μm, and more preferably 50 μm to 400 μm, from the viewpoint of enhancing the bending durability of the endless belt.

[0066] The thickness of the belt is measured as follows. That is, the film thickness of the belt to be measured is measured at the following measurement positions. First, measure the entire width of the belt at 5 mm intervals along the axial direction of the belt, and measure at four locations at 90° intervals around the circumference of the belt. The thickness of the belt is measured using an eddy current film thickness meter ISOSCOPE MP30 manufactured by Fisher Instruments.

[0067] [Manufacturing method] The endless belt according to the present disclosure is manufactured by the following method. That is, the endless belt according to the present disclosure is obtained by preparing a coating liquid containing each component constituting the belt, applying the coating liquid to a cylindrical substrate, and drying the coating liquid. The coating liquid contains a resin, a needle-like filler, and other components (additives) that are used as needed. When the resin is polyimide, the endless belt according to the present disclosure is obtained by preparing a coating liquid containing polyamic acid (a precursor of polyimide resin), a needle-like filler, other components (additives) used as needed, and the like, applying the obtained coating liquid onto a cylindrical substrate, and baking the coating liquid (i.e., imidization).

[0068] When preparing the coating liquid, a dispersion in which the needle-shaped filler is dispersed in a solvent may be used in advance. In this case, the coating liquid is obtained by dissolving the resin (or polyamic acid) in the obtained dispersion. When obtaining a dispersion containing acicular fillers, for example, a dispersion method such as a ball mill, a sand mill, a bead mill, or a jet mill (a counter-collision type disperser) is used, as well as high-pressure dispersion using a high-pressure homogenizer or the like. The coating method of the coating liquid is not particularly limited, but for example, a flow coating method (spiral winding coating method) is used. By using the flow coating method, as described above, a form in which the needle-like filler particles are oriented in the circumferential direction of the endless belt is obtained.

[0069] <Fixing belt> The fixing belt according to the present disclosure includes the endless belt according to the present disclosure described above, a surface layer provided on the outer peripheral surface of the endless belt, and preferably further includes an elastic layer provided between the endless belt and the surface layer. That is, the fixing belt according to the present disclosure has the aforementioned endless belt according to the present disclosure as a base layer, and has a surface layer thereon, or has an elastic layer and a surface layer. The fixing belt according to the present disclosure has a substrate layer made of the endless belt according to the present disclosure, which has high thermal conductivity and electrical insulation in the circumferential direction and excellent flexural durability. This allows for a shorter temperature rise time, reduced power consumption, faster fixing speed, and a longer lifespan. The endless belt according to the present disclosure also has excellent thermal conductivity in the circumferential direction, making it less susceptible to temperature distribution in the circumferential direction of the endless belt. A fixing belt according to the present disclosure, which includes the endless belt according to the present disclosure, also reduces the time from the start of an image formation operation (e.g., an image formation instruction from a user, the start of scanning a document to be copied, etc.) to the completion of image formation on the first recording medium and output (the so-called FPOT, first printout time). Furthermore, when the needle-like filler is aluminum nitride single crystal, the endless belt according to the present disclosure is less susceptible to dimensional fluctuation due to moisture absorption. Therefore, a fixing belt according to the present disclosure, which includes this endless belt, also has excellent dimensional stability. As a result, image defects caused by dimensional fluctuations of the fixing belt can be suppressed.

[0070] The fixing belt according to the present disclosure will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view showing an example of a fixing belt according to the present disclosure. The fixing belt 110 shown in FIG. 1 has a base layer 110A, an elastic layer 110B provided on the base layer 110A, and a surface layer 110C provided on the elastic layer 110B. The layer structure of the fixing belt 110 according to the present disclosure is not limited to the layer structure shown in FIG. 1, but may be a layer structure in which an adhesive layer is interposed between the base layer 110A and the elastic layer 110B, a layer structure in which an adhesive layer is interposed between the elastic layer 110B and the surface layer 110C, a layer structure without the elastic layer 110B, a layer structure without the surface layer 110C, or a layer structure that combines these layer structures.

[0071] The main components of the fixing belt according to the present disclosure will be described in detail below, with the reference numerals omitted.

[0072] (base material layer) In the fixing belt according to the present disclosure, the endless belt according to the present disclosure is used as a substrate layer. From the viewpoints of thermal conductivity, insulation, and bending durability in the circumferential direction, the thickness of the base material layer in the fixing belt according to the present disclosure is preferably 50 μm or more and 110 μm or less, more preferably 60 μm or more and 100 μm or less, and particularly preferably 70 μm or more and 90 μm or less.

[0073] The base layer may be formed by the above-described method for manufacturing an endless belt according to the present disclosure.

[0074] (elastic layer) The fixing belt according to the present disclosure preferably has an elastic layer on a base material layer (that is, the endless belt according to the present disclosure). The elastic layer is not particularly limited as long as it is a layer having elasticity. The elastic layer is a layer provided to provide elasticity to the fixing belt against pressure from the outer periphery, and plays a role in following the unevenness of the toner image on the recording medium, allowing the surface of the fixing belt to adhere closely to the toner image.

[0075] The elastic layer is preferably made of an elastic material that can restore its original shape even when deformed by application of an external force of, for example, 100 Pa. Examples of elastic materials used for the elastic layer include fluororesin, silicone resin, silicone rubber, fluororubber, fluorosilicone rubber, etc. As the material for the elastic layer, silicone rubber and fluororubber are preferred, and silicone rubber is more preferred, from the viewpoints of heat resistance, thermal conductivity, insulation, etc.

[0076] Examples of silicone rubber include RTV silicone rubber, HTV silicone rubber, and liquid silicone rubber, and specific examples include polydimethyl silicone rubber (MQ), methyl vinyl silicone rubber (VMQ), methyl phenyl silicone rubber (PMQ), and fluorosilicone rubber (FVMQ).

[0077] Silicone rubbers that are primarily crosslinked by addition reaction are preferred. Various types of functional groups are known for silicone rubbers, and preferred examples include dimethyl silicone rubbers with methyl groups, methylphenyl silicone rubbers with methyl and phenyl groups, and vinyl silicone rubbers with vinyl groups (vinyl group-containing silicone rubbers). Furthermore, as the silicone rubber, vinyl silicone rubber having a vinyl group is more preferable, and silicone rubber having an organopolysiloxane structure having a vinyl group and a hydrogenorganopolysiloxane structure having a hydrogen atom (SiH) bonded to a silicon atom is even more preferable.

[0078] Examples of fluororubbers include vinylidene fluoride rubber, tetrafluoroethylene / propylene rubber, tetrafluoroethylene / perfluoromethylvinyl ether rubber, phosphazene rubber, and fluoropolyether.

[0079] The elastic material used for the elastic layer preferably contains silicone rubber as a main component (that is, the elastic material contains silicone rubber in an amount of 50% by mass or more relative to the total mass of the elastic material). The content of the silicone rubber is more preferably 90% by mass or more, further preferably 99% by mass or more, and may be 100% by mass, based on the total mass of the elastic material used in the elastic layer.

[0080] In addition to the elastic material, the elastic layer may contain an inorganic filler for the purposes of reinforcement, heat resistance, heat transfer, etc. Examples of inorganic fillers include known ones, and preferred examples include fumed silica, crystalline silica, iron oxide, alumina, metallic silicon, etc. In addition to the above, examples of inorganic filler materials include well-known inorganic fillers such as carbides (e.g., carbon black, carbon fiber, carbon nanotubes, etc.), titanium oxide, silicon carbide, talc, mica, kaolin, calcium carbonate, calcium silicate, magnesium oxide, graphite, silicon nitride, boron nitride, cerium oxide, and magnesium carbonate. Among these, silicon nitride, silicon carbide, graphite, boron nitride, and carbides are preferred from the viewpoint of thermal conductivity. The inorganic filler in the elastic layer may be the specific needle-like filler described above. Specifically, aluminum nitride single crystal may be used as the inorganic filler. The content of inorganic filler in the elastic layer may be determined based on the required thermal conductivity, mechanical strength, etc., and may be, for example, 1% by mass or more and 20% by mass or less, preferably 3% by mass or more and 15% by mass or less, and more preferably 5% by mass or more and 10% by mass or less. Furthermore, the content of the specific needle-shaped filler in the elastic layer may be determined based on the required thermal conductivity, mechanical strength, etc., and may be, for example, 3% by mass or more and 25% by mass or less, preferably 10% by mass or more and 20% by mass or less, and more preferably 12% by mass or more and 18% by mass or less.

[0081] The elastic layer may also contain additives such as softeners (paraffin-based, etc.), processing aids (stearic acid, etc.), antioxidants (amine-based, etc.), and vulcanizing agents (sulfur, metal oxides, peroxides, etc.).

[0082] The thickness of the elastic layer is, for example, preferably 30 μm or more and 600 μm or less, and more preferably 100 μm or more and 500 μm or less.

[0083] The elastic layer may be formed by a known method, for example, a coating method. When silicone rubber is used as the elastic material of the elastic layer, for example, first, a coating liquid for forming an elastic layer containing a liquid silicone rubber that is cured by heating to form silicone rubber is prepared. Next, the coating liquid for forming an elastic layer is applied to a substrate layer to form a coating film, and the coating film is vulcanized as needed to form an elastic layer on the substrate layer. In addition, in vulcanizing the coating film, the vulcanization temperature can be, for example, 150°C or higher and 250°C or lower, and the vulcanization time can be, for example, 30 minutes or higher and 120 minutes or lower.

[0084] (Surface layer) The fixing belt according to the present disclosure preferably has a surface layer on the base layer or the elastic layer. The surface layer is a layer that plays a role in preventing the molten toner image from sticking to the surface (outer peripheral surface) that comes into contact with the recording medium during fixing.

[0085] The surface layer is required to have, for example, heat resistance and releasability. From this viewpoint, it is preferable to use a heat-resistant release material as the material for the surface layer, and specific examples thereof include fluororubber, fluororesin, silicone resin, and polyimide resin. Among these, fluororesin is preferable as a heat-resistant release material. Specific examples of fluororesins include tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), polyethylene-tetrafluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), and polyvinyl fluoride (PVF).

[0086] The surface of the surface layer facing the elastic layer may be subjected to a surface treatment, which may be a wet treatment or a dry treatment, such as a liquid ammonia treatment, an excimer laser treatment, or a plasma treatment.

[0087] The thickness of the surface layer is preferably 10 μm or more and 100 μm or less, and more preferably 20 μm or more and 50 μm or less.

[0088] The surface layer may be formed by a known method, for example, a coating method. Alternatively, a tubular surface layer may be prepared in advance and then coated on the outer periphery of the elastic layer to form the surface layer. Alternatively, an adhesive layer (e.g., an adhesive layer containing a silane coupling agent having an epoxy group) may be formed on the inner surface of the tubular surface layer, and then the outer periphery may be coated with the adhesive layer.

[0089] The thickness of the fixing belt according to the present disclosure is, for example, preferably 90 μm or more and 600 μm or less, more preferably 200 μm or more and 600 μm or less, and even more preferably 300 μm or more and 550 μm or less.

[0090] [Use of fixing belt components] The fixing belt according to the present disclosure is applicable to, for example, either a heating belt or a pressure belt.

[0091] <Fixing device> The fixing device according to the present disclosure may have various configurations, such as a fixing device including a first rotating body and a second rotating body arranged in contact with the outer surface of the first rotating body, in which a recording medium having a toner image formed on its surface is inserted through a contact portion between the first rotating body and the second rotating body to fix the toner image. The fixing belt according to the present disclosure is used as at least one of the first rotating body and the second rotating body.

[0092] Hereinafter, a fixing device according to the present disclosure will be described, with a fixing device including a heating roll and a pressure belt as a first embodiment, and a fixing device including a heating belt and a pressure roll as a second embodiment. In the first embodiment, the fixing belt according to the present disclosure can be applied to either the heating belt or the pressure belt. The fixing device according to the present disclosure is not limited to the first and second embodiments, and may be a fixing device including a heating roll or a heating belt and a pressure belt. The fixing belt according to the present disclosure may be applied to either the heating belt or the pressure belt.

[0093] The base layer of the fixing belt according to the present disclosure contains needle-like fillers, which themselves have excellent insulating properties, and the endless belt according to the present disclosure has excellent insulating properties as a belt. Therefore, the fixing belt according to the present disclosure is suitable for a configuration having a heating pressure roll (i.e., a heating pressure roll equipped with a heating means) that presses the heating belt against the pressure roll from its inner circumferential surface in the sandwiching region N (nip portion), as shown in the second embodiment of the fixing device below. When the fixing belt according to the present disclosure is applied to a fixing device having such a configuration, the base layer made of the endless belt according to the present disclosure ensures and maintains insulation between the fixing belt according to the present disclosure and the heating pressure roll, thereby stabilizing fixing by the fixing device.

[0094] (First embodiment of fixing device) A first embodiment of the fixing device will be described with reference to Fig. 2. Fig. 2 is a schematic diagram showing an example of the first embodiment of the fixing device (that is, fixing device 60).

[0095] As shown in FIG. 2, the fixing device 60 is configured to include, for example, a rotating heating roll 61 (an example of a first rotating body), a pressure belt 62 (an example of a second rotating body), and a pressure pad 64 (an example of a pressure member) that presses the heating roll 61 via the pressure belt 62. The pressure pad 64 may be configured to relatively press the pressure belt 62 and the heating roll 61. Therefore, the pressure belt 62 may be pressed against the heating roll 61, or the heating roll 61 may be pressed against the heating roll 61.

[0096] A halogen lamp 66 (an example of a heating means) is disposed inside the heating roll 61. The heating means is not limited to a halogen lamp, and other heat-generating members may also be used.

[0097] On the other hand, for example, a temperature sensor 69 is placed in contact with the surface of the heating roll 61. Based on the temperature measurement value by this 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).

[0098] The pressure belt 62 is rotatably supported by, for example, a pressure pad 64 and a belt running guide 63 disposed inside the pressure belt 62. The pressure belt 62 is disposed so as to be pressed against the heating roll 61 by the pressure pad 64 in the sandwiching region N (nip portion).

[0099] The pressure pad 64 is disposed, for example, inside the pressure belt 62 in a state where it is pressed against the heating roll 61 via the pressure belt 62, and forms a sandwiched region N between the pressure pad 64 and the heating roll 61. The pressure pad 64 has, for example, a front clamping member 64a arranged on the entrance side of the clamping area N to ensure a wide clamping area N, and a peeling clamping member 64b arranged on the exit side of the clamping area N to apply distortion to the heating roll 61.

[0100] In order to reduce the sliding resistance between the inner peripheral surface of the pressure belt 62 and the pressure pad 64, for example, a sheet-like sliding member 68 is provided on the surfaces of the front clamping member 64a and the peeling clamping member 64b that come into contact with the pressure belt 62. The pressure pad 64 and the sliding member 68 are held by a holding member 65 made of metal. The sliding member 68 is provided so that its sliding surface comes into contact with the inner circumferential surface of the pressure belt 62 , and is involved in the retention and supply of oil present between it and the pressure belt 62 .

[0101] For example, a belt running guide 63 is attached to the holding member 65, and the pressure belt 62 rotates.

[0102] The heating roll 61 is rotated in the direction of arrow S by, for example, a drive motor (not shown), and the pressure belt 62 is driven by this rotation to rotate in the direction of arrow R, which is opposite to the rotation direction of the heating roll 61. That is, for example, while the heating roll 61 rotates in the clockwise direction in FIG. 2, the pressure belt 62 rotates in the counterclockwise direction.

[0103] Then, the paper K (an example of a recording medium) having the unfixed toner image thereon is guided, for example, by the fixing entrance guide 56 and transported to the nip area N. Then, as the paper K passes through the nip area N, the unfixed toner image on the paper K is fixed by the pressure and heat acting on the nip area N.

[0104] In the fixing device 60, for example, the front pinch member 64a has a concave shape that conforms to the outer peripheral surface of the heating roll 61, thereby ensuring a wider pinch region N than in a configuration without the front pinch member 64a.

[0105] In addition, the fixing device 60 is configured such that, for example, by arranging a peeling and pinching member 64b that protrudes from the outer peripheral surface of the heating roll 61, the distortion of the heating roll 61 is locally increased in the exit area of ​​the pinching area N.

[0106] By arranging the peeling and pinching member 64b in this manner, for example, when the paper K after fixing passes through the peeling and pinching area, it passes through a locally large distortion, making it easier for the paper K to peel off from the heating roll 61.

[0107] As an auxiliary means for peeling, for example, a peeling member 70 is disposed downstream of the pinch region N of the heating roll 61. The peeling member 70 is held by a holding member 72 in a state in which a peeling claw 71 is close to the heating roll 61 in a direction opposite to the rotation direction of the heating roll 61 (counter direction), for example.

[0108] (Second embodiment of fixing device) A second embodiment of the fixing device will be described with reference to Fig. 3. Fig. 3 is a schematic diagram showing an example of the second embodiment of the fixing device (that is, fixing device 80).

[0109] 3, the fixing device 80 includes, for example, a fixing belt module 86 equipped with 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 press against the heating belt 84 (fixing belt module 86). A nip region N (a nip portion) is formed at the contact portion between the heating belt 84 (fixing belt module 86) and the pressure roll 88. In the nip region N, a sheet of paper K (an example of a recording medium) is pressurized and heated, and a toner image is fixed thereon.

[0110] The fixing belt module 86 includes, for example, an endless heating belt 84, a heating pressure roll 89 around which the heating belt 84 is wound on the pressure roll 88 side and which is driven to rotate by the rotational force of a motor (not shown) and presses the heating belt 84 from its inner surface against the pressure roll 88 side, and a support roll 90 which supports the heating belt 84 from the inside at a position different from the heating pressure roll 89. The fixing belt module 86 includes, for example, a support roll 92 arranged outside the heating belt 84 to define its circulation path, an attitude correction roll 94 to correct the attitude of the heating belt 84 from the heating pressure roll 89 to the support roll 90, and a support roll 98 to apply tension to the heating belt 84 from its inner surface downstream of the clamping area N formed by the heating belt 84 and the pressure roll 88.

[0111] The fixing belt module 86 is provided, for example, such that a sheet-like sliding member 82 is interposed between the heating belt 84 and the heating pressure roll 89 . The sliding member 82 is provided, for example, so that its sliding surface comes into contact with the inner circumferential surface of the heating belt 84 , and is involved in the retention and supply of oil present between it and the heating belt 84 . Here, the sliding member 82 is provided in a state where both ends thereof are supported by support members 96, for example.

[0112] Inside the heating pressure roll 89, for example, a halogen heater 89A (an example of a heating means) is provided.

[0113] The support roll 90 is, for example, a cylindrical roll made of aluminum, and has a halogen heater 90A (an example of a heating means) disposed therein, which heats the heating belt 84 from the inner peripheral surface side. At both ends of the support roll 90, for example, spring members (not shown) are arranged to press the heating belt 84 outward.

[0114] The support roll 92 is a cylindrical roll made of, for example, aluminum, and has a release layer made of fluororesin and having a thickness of 20 μm formed on the surface of the support roll 92. The release layer of the support roll 92 is formed to prevent, for example, toner and paper dust from the outer peripheral surface of the heating belt 84 from accumulating on the support roll 92 . Inside the support roll 92, for example, a halogen heater 92A (an example of a heating means) is disposed, and the heating belt 84 is heated from the outer peripheral surface side.

[0115] That is, for example, the heating belt 84 is heated by the heating pressure roll 89 and the support rolls 90 and 92 .

[0116] The posture correction roll 94 is, for example, a cylindrical roll made of aluminum, and an end position measuring mechanism (not shown) that measures the end position of the heating belt 84 is disposed near the posture correction roll 94. The posture correction roll 94 is provided with, for example, an axial displacement mechanism (not shown) that displaces the contact position in the axial direction of the heating belt 84 in accordance with the measurement results of the end position measurement mechanism, and is configured to control the meandering of the heating belt 84.

[0117] On the other hand, the pressure roll 88 is, for example, supported rotatably and is provided so as to be pressed against the portion where the heating belt 84 is wound around the heating pressure roll 89 by a biasing means such as a spring (not shown). As a result, as the heating belt 84 (heating pressure roll 89) of the fixing belt module 86 rotates and moves in the direction of arrow S, the pressure roll 88 rotates and moves in the direction of arrow R, following the heating belt 84 (heating pressure roll 89).

[0118] Then, the paper K having an unfixed toner image (not shown) is transported in the direction of arrow P and guided to a pinch area N of the fixing device 80. Then, as the paper K passes through the pinch area N, the unfixed toner image on the paper K is fixed by the pressure and heat acting on the pinch area N.

[0119] In the fixing device 80, a form in which a halogen heater (halogen lamp) is used as an example of a plurality of heating means has been described, but this is not limited to this, and a radiant lamp heating element (a heating element that emits radiation (infrared rays, etc.)) other than a halogen heater, or a resistance heating element (a heating element that generates Joule heat by passing an electric current through a resistor: for example, a ceramic substrate on which a resistive film is formed and then fired) may also be used.

[0120] [Image forming device] Next, an image forming apparatus according to the present disclosure will be described. The image forming apparatus according to the present disclosure includes an image carrier, a charging means for charging the surface of the image carrier, an electrostatic latent image forming means for forming an electrostatic latent image on the surface of the charged image carrier, a developing means for developing the electrostatic latent image formed on the surface of the image carrier with a developer containing toner to form a toner image, a transfer means for transferring the toner image to the surface of a recording medium, and a fixing means for fixing the toner image to the recording medium. The fixing device according to the present disclosure is applied as the fixing means.

[0121] In the image forming apparatus according to the present disclosure, the fixing device may be formed as a cartridge that is detachably attached to the image forming apparatus, i.e., the image forming apparatus according to the present disclosure may include the fixing device according to the present disclosure as a component of a process cartridge.

[0122] An image forming apparatus according to the present disclosure will be described below with reference to the drawings. FIG. 4 is a schematic diagram showing the configuration of the image forming apparatus according to the present disclosure.

[0123] 4, image forming apparatus 100 according to the present disclosure is, for example, an intermediate transfer type image forming apparatus generally called a tandem type, and includes a plurality of image forming units 1Y, 1M, 1C, and 1K that form toner images of each color component by electrophotography, a primary transfer unit 10 that sequentially transfers (primary transfer) the toner images of each color component formed by each image forming unit 1Y, 1M, 1C, and 1K onto an intermediate transfer belt 15, a secondary transfer unit 20 that collectively transfers (secondary transfer) the superimposed toner images transferred onto intermediate transfer belt 15 onto paper K, which is a recording medium, and a fixing device 60 that fixes the secondarily transferred image onto paper K. Image forming apparatus 100 also has a control unit 40 that controls the operation of each device (each unit).

[0124] This fixing device 60 is the first embodiment of the fixing device described above. Note that the image forming apparatus 100 may be configured to include the second embodiment of the fixing device described above.

[0125] Each of the image forming units 1Y, 1M, 1C, and 1K of the image forming apparatus 100 includes a photoconductor 11 that rotates in the direction of arrow A as an example of an image carrier that carries a toner image formed on its surface.

[0126] Around the photosensitive member 11, there is provided a charger 12 as an example of a charging means for charging the photosensitive member 11, and there is provided a laser exposure device 13 (the exposure beam is indicated by the symbol Bm in the figure) as an example of a latent image forming means for writing an electrostatic latent image on the photosensitive member 11.

[0127] In addition, around the photosensitive member 11, there is provided a developing device 14 as an example of a developing means, which contains toner of each color component and makes the electrostatic latent image on the photosensitive member 11 visible using the toner, and there is provided a primary transfer roll 16 which transfers the toner image of each color component formed on the photosensitive member 11 to an intermediate transfer belt 15 at the primary transfer section 10.

[0128] Furthermore, a photoreceptor cleaner 17 is provided around the photoreceptor 11 to remove residual toner from the photoreceptor 11, and electrophotographic devices including a charger 12, a laser exposure device 13, a developing device 14, a primary transfer roll 16, and the photoreceptor cleaner 17 are arranged in this order along the rotation direction of the photoreceptor 11. These image forming units 1Y, 1M, 1C, and 1K are arranged in a substantially linear fashion from the upstream side of the intermediate transfer belt 15 in the order of yellow (Y), magenta (M), cyan (C), and black (K).

[0129] The intermediate transfer belt 15, which is an intermediate transfer body, is a film-like pressure belt that has a base layer of resin such as polyimide or polyamide and contains an appropriate amount of antistatic agent such as carbon black. 6 Ωcm or more 10 14 It is formed to have a resistivity of Ωcm or less, and its thickness is set to, for example, about 0.1 mm.

[0130] The intermediate transfer belt 15 is driven (rotated) in a circular manner in the direction B shown in Fig. 4 at a speed suited to the purpose by various rolls. These rolls include a drive roll 31 that is driven by a motor (not shown) with excellent constant speed performance to rotate the intermediate transfer belt 15, a support roll 32 that supports the intermediate transfer belt 15 that extends in a substantially straight line along the arrangement direction of the photoconductors 11, a tensioning roll 33 that applies tension to the intermediate transfer belt 15 and functions as a correction roll that prevents the intermediate transfer belt 15 from meandering, a backing roll 25 provided in the secondary transfer unit 20, and a cleaning backing roll 34 provided in a cleaning unit that scrapes off residual toner on the intermediate transfer belt 15.

[0131] The primary transfer unit 10 is composed of a primary transfer roll 16 disposed opposite the photoreceptor 11 with an intermediate transfer belt 15 sandwiched therebetween. The primary transfer roll 16 is composed of a core body and a sponge layer as an elastic layer fixed to the periphery of the core body. The core body is a cylindrical rod made of a metal such as iron or SUS. The sponge layer is made of a blend rubber of NBR, SBR and EPDM mixed with a conductive agent such as carbon black, and has a volume resistivity of 10 7.5 Ωcm or more 10 8.5 It is a sponge-like cylindrical roll with a resistance of less than Ωcm.

[0132] The primary transfer roll 16 is arranged in pressure contact with the photosensitive member 11 with the intermediate transfer belt 15 sandwiched therebetween, and furthermore, 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 each photosensitive member 11 are electrostatically attracted to the intermediate transfer belt 15 in sequence, and superimposed toner images are formed on the intermediate transfer belt 15.

[0133] The secondary transfer unit 20 is configured to include a back roll 25 and a secondary transfer roll 22 that is disposed on the toner image bearing surface side of the intermediate transfer belt 15 .

[0134] The back roll 25 is made of a tube of EPDM and NBR blend rubber with carbon dispersed on the surface, and the inside is made of EPDM rubber. 7 Ω / □ or more 10 10 The hardness is set to, for example, 70° (Asker C, manufactured by Kobunshi Keiki Co., Ltd.; the same applies hereinafter.) The back roll 25 is disposed on the back side of the intermediate transfer belt 15 and constitutes an opposing electrode of the secondary transfer roll 22, and is in contact with a metal power supply roll 26 to which a secondary transfer bias is stably applied.

[0135] On the other hand, the secondary transfer roll 22 is composed of a core body and a sponge layer as an elastic layer fixed around the core body. The core body is a cylindrical rod made of a metal such as iron or SUS. The sponge layer is made of a blend rubber of NBR, SBR and EPDM mixed with a conductive agent such as carbon black, and has a volume resistivity of 10 7.5 Ωcm or more 10 8.5 It is a sponge-like cylindrical roll with a resistance of less than Ωcm.

[0136] The secondary transfer roll 22 is placed in pressure contact with the back roll 25 with the intermediate transfer belt 15 sandwiched therebetween, and furthermore, the secondary transfer roll 22 is grounded to form a secondary transfer bias between it and the back roll 25, thereby secondarily transferring the toner image onto the paper K being transported to the secondary transfer section 20.

[0137] In addition, downstream of the secondary transfer section 20 of the intermediate transfer belt 15, an intermediate transfer belt cleaner 35 is provided so as to be freely movable toward and away from the intermediate transfer belt 15, which removes residual toner and paper dust from the intermediate transfer belt 15 after the secondary transfer and cleans the surface of the intermediate transfer belt 15.

[0138] The intermediate transfer belt 15, the primary transfer section 10 (primary transfer roll 16), and the secondary transfer section 20 (secondary transfer roll 22) correspond to an example of a transfer unit.

[0139] Meanwhile, upstream of the yellow image forming unit 1Y, there is provided a reference sensor (home position sensor) 42 that generates a reference signal that serves as a reference for timing image formation in each of the image forming units 1Y, 1M, 1C, and 1K. This reference sensor 42 generates a reference signal by recognizing a mark provided on the back side of the intermediate transfer belt 15, and each of the image forming units 1Y, 1M, 1C, and 1K is configured to start image formation in response to an instruction from the control unit 40 based on the recognition of this reference signal. Further, an image density sensor 43 for adjusting image quality is disposed downstream of the black image forming unit 1K.

[0140] Furthermore, the image forming apparatus according to the present disclosure is equipped with, as transport means for transporting paper K, a paper storage section 50 for storing paper K, a paper feed roll 51 for taking out and transporting paper K accumulated in the paper storage section 50 at a predetermined timing, a transport roll 52 for transporting paper K unwound by the paper feed roll 51, a transport guide 53 for sending paper K transported by the transport roll 52 to the secondary transfer section 20, a transport belt 55 for transporting paper K transported after secondary transfer by the secondary transfer roll 22 to the fixing device 60, and a fixing entrance guide 56 for guiding paper K to the fixing device 60.

[0141] Next, the basic image forming process of the image forming apparatus according to the present disclosure will be described. In the image forming apparatus of the present disclosure, image data output from an image reading device (not shown) or a personal computer (PC) (not shown) is subjected to image processing by an image processing device (not shown), and then image formation is performed by image forming units 1Y, 1M, 1C, and 1K.

[0142] The image processing device performs image processing on the input reflectance data, such as shading correction, positional deviation correction, brightness / color space conversion, gamma correction, and various image editing operations such as frame erasure, color editing, and movement editing. The image data that has undergone image processing is converted into color material gradation data for four colors, Y, M, C, and K, and output to the laser exposure device 13.

[0143] In accordance with the input color material gradation data, the laser exposure device 13 irradiates the photoconductor 11 of each of the image forming units 1Y, 1M, 1C, and 1K with an exposure beam Bm emitted from, for example, a semiconductor laser. After the surface of the photoconductor 11 of each of the image forming units 1Y, 1M, 1C, and 1K is charged by the charger 12, the surface is scanned and exposed by the laser exposure device 13 to form an electrostatic latent image. The formed electrostatic latent image is developed into a toner image of each color of Y, M, C, and K by each of the image forming units 1Y, 1M, 1C, and 1K.

[0144] 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 each photoconductor 11 comes into contact with the intermediate transfer belt 15. More specifically, 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 base material of the intermediate transfer belt 15 by the primary transfer roll 16, and the toner images are sequentially superimposed on the surface of the intermediate transfer belt 15 to perform the primary transfer.

[0145] After the toner images are sequentially transferred (primary transfer) onto the surface of the intermediate transfer belt 15, the intermediate transfer belt 15 moves, and the toner images are transported to the secondary transfer unit 20. When the toner images are transported to the secondary transfer unit 20, the transport means rotates the paper feed roll 51 in synchronization with the timing at which the toner images are transported to the secondary transfer unit 20, and paper K of the desired size is supplied from the paper storage unit 50. The paper K supplied by the paper feed roll 51 is transported by the transport roll 52 and reaches the secondary transfer unit 20 via the transport guide 53. Before reaching the secondary transfer unit 20, the paper K is temporarily stopped, and a positioning roll (not shown) rotates in synchronization with the movement of the intermediate transfer belt 15 on which the toner images are held, thereby aligning the position of the paper K with the position of the toner image.

[0146] In the secondary transfer unit 20, the secondary transfer roll 22 is pressed against the back roll 25 via the intermediate transfer belt 15. At this time, the paper K, which has been conveyed in time, is sandwiched between the intermediate transfer belt 15 and the secondary transfer roll 22. At this time, when a voltage (secondary transfer bias) of the same polarity as the charge polarity (negative polarity) of the toner is applied from the power supply roll 26, a transfer electric field is formed between the secondary transfer roll 22 and the back roll 25. Then, the unfixed toner images held on the intermediate transfer belt 15 are electrostatically transferred onto the paper K all at once in the secondary transfer unit 20, which is pressed by the secondary transfer roll 22 and the back roll 25.

[0147] Thereafter, the paper sheet K onto which the toner image has been electrostatically transferred is transported as is after being peeled off from the intermediate transfer belt 15 by the secondary transfer roll 22, and is transported to a transport belt 55 provided downstream of the secondary transfer roll 22 in the paper transport direction. The transport belt 55 transports the paper sheet K to the fixing device 60 at an optimal transport speed for the fixing device 60. The unfixed toner image on the paper sheet K transported to the fixing device 60 is fixed onto the paper sheet K by being subjected to a fixing process using heat and pressure by the fixing device 60. Then, the paper sheet K on which the fixed image has been formed is transported to an ejected paper storage unit (not shown) provided in the ejection unit of the image forming apparatus.

[0148] On the other hand, after the transfer to the paper K is completed, the residual toner remaining on the intermediate transfer belt 15 is transported to the cleaning section as the intermediate transfer belt 15 rotates, and is removed from the intermediate transfer belt 15 by the cleaning back roll 34 and the intermediate transfer belt cleaner 35.

[0149] Although the present embodiment has been described above, it should not be construed as being limited to the above embodiment, and various modifications, changes, and improvements are possible. [Example]

[0150] The present invention will be described in more detail below with reference to examples, although the present invention is not limited to the following examples.

[0151] Example 1 (Formation of base layer (endless belt)) A dispersion was prepared by mixing N-methyl-2-pyrrolidone (NMP) and acicular aluminum nitride single crystals in a mass ratio of 82:18. The resulting dispersion was subjected to high-pressure dispersion treatment (conditions: 200 MPa, 3 times) using a high-pressure homogenizer (manufactured by Sanmaru Machinery Industry Co., Ltd., HC3). Next, 1000 parts by mass of a polyamic acid solution (TX-HMM (polyimide varnish) manufactured by Unitika Ltd., solid content concentration: 18% by mass, solvent: NMP) was added to 100 parts by mass of the dispersion liquid after the high-pressure dispersion treatment, and the mixture was stirred for 60 minutes while vacuuming using a planetary mixer (Aikosha Seisakusho Co., Ltd., ACM-5LVT). As a result, a coating solution containing 10 mass % of acicular aluminum nitride single crystals in the solid content was obtained. Next, the obtained coating liquid was applied onto a cylindrical mold using a flow coating method (conditions: mold rotation speed 500 rpm, movement speed of the discharge part in the direction of the mold rotation axis 100 mm / min) to form a coating film, and the coating film was baked at 380°C to form an endless belt (substrate layer) with a thickness of 80 μm.

[0152] (Formation of elastic layer) Next, liquid silicone rubber (X34-1053, manufactured by Shin-Etsu Chemical Co., Ltd.) was applied to the outer peripheral surface of the obtained base layer and heated at 110° C. for 15 minutes to obtain an elastic layer with a thickness of 400 μm.

[0153] (Formation of surface layer) Next, a fluororesin tube containing PFA and having a thickness of 30 μm was formed by injection molding. This fluororesin tube was placed on the elastic layer and heated at 200° C. for 120 minutes to form a surface layer made of the fluororesin tube.

[0154] Through the above steps, a fixing belt was obtained.

[0155] <Examples 2 to 16 and Comparative Examples 1 to 9> An endless belt (substrate layer) was formed in the same manner as in Example 1, except that in forming the substrate layer of Example 1, the type and amount of filler added were appropriately changed as shown in Table 1 or Table 2. Next, an elastic layer and a surface layer were formed on this substrate layer in the same manner as in Example 1, to produce a fixing belt. In Example 16, 85 parts by mass of liquid silicone rubber (X34-1053, manufactured by Shin-Etsu Chemical Co., Ltd.) and a thermal conductivity of 270 W / mK and a volume resistivity of 10 15An elastic layer was formed in the same manner as in Example 1, except that a coating solution containing 15 parts by mass of acicular aluminum nitride single crystals with a resistivity of Ωcm was used, and then a surface layer was formed in the same manner as in Example 1.

[0156] <Measurement of thermal conductivity and volume resistivity> The thermal conductivity and volume resistivity of the filler used in each example were measured according to the methods already described. The thermal conductivity and volume resistivity of the substrate layer obtained in each example were also measured according to the methods described above. The results are shown in Tables 1 and 2. In the column "Difficulty in reacting with water" in Tables 1 and 2, fillers used in each example that have the property of being difficult to react with water are marked with A. The granular aluminum nitride used in Comparative Examples 1 and 6 is less difficult to react with water than the acicular aluminum nitride single crystals, and therefore its difficulty in reacting with water is marked with "B."

[0157] <Dimensional accuracy> The dimensional accuracy of the substrate layer obtained in each example was evaluated according to the following method. That is, the endless belt (base layer) thus produced was stored for 24 hours in a high humidity environment of 28°C and 85 RH%, and the belt circumference was measured. The dimensional variation rate was calculated based on the difference in the belt circumference before and after storage, and evaluated according to the following criteria. The dimensional variation rate [%] was calculated using the following formula. Dimensional variation rate [%] = (Belt circumference after storage - Belt circumference before storage) / Belt circumference before storage x 100 -standard- A: Dimensional variation rate is less than 1% B: Dimensional variation rate is 1% or more and less than 3% C: Dimensional variation rate is 3% or more

[0158] <Evaluation of bending durability> The substrate layer obtained in each example was attached to a fixing device of an image forming apparatus (Versant 3100 Press, manufactured by Fujifilm Business Innovation Co., Ltd.). Using this image forming apparatus, a 10% halftone image was continuously output on A4 paper up to a maximum of 1 million sheets. The fixing belt was removed every 100,000 sheets of output, and the presence or absence of cracks and breaks in the removed fixing belt was visually confirmed. The bending durability was evaluated according to the following criteria. - Criteria - A: No cracks or breaks were observed in the base material layer up to 1 million sheets. B: Cracks or breaks were observed in the base material layer at 700,000 sheets or more and less than 1 million sheets. C: Cracks or breaks were observed in the base material layer at less than 700,000 sheets.

[0159] <Fixing stability> The fixing belts obtained in each example were installed in the fixing device of an image forming apparatus (Versant 3100 Press manufactured by Fujifilm Business Innovation Co., Ltd.). Using this image forming apparatus, a 10% halftone image was continuously output on A3 paper for 30 sheets. For the 30 sheets output, the presence or absence of image disturbance due to toner scattering in front of the fixing nip portion was visually confirmed. The image disturbance caused by toner scattering occurring here is considered to occur by affecting the charging characteristics of the toner on the paper when the insulation between the fixing belt and the heating and pressing roll is not ensured. The fixing stability was evaluated according to the following criteria. - Criteria - A: No image disturbance due to toner scattering was observed in all 30 sheets. B: Image disturbance due to toner scattering was observed in 1 or more and less than 10 sheets. C: Image disturbance due to toner scattering was observed in 10 or more sheets.

[0160] <Evaluation of FPOT> The fixing belts obtained in each example were installed in the fixing device of the above image forming apparatus, and the FPOT was measured when the fixing device was heated by applying 1200 W of power from the room temperature state. The FPOT was evaluated according to the following criteria. - Criteria - A: The FPOT was less than 30 seconds. B: FPOT was more than 30 seconds but less than 1 minute. C:FPOT was more than 1 minute.

[0161] <Evaluation of image defects> The fixing belt obtained in each example was installed in the fixing device of the image forming apparatus described above, and the image forming apparatus was stored for 24 hours in a high-humidity environment of 28°C and 85% RH, after which 30 sheets of 10% halftone images were continuously printed on A3 paper. The 30 printed sheets were visually inspected for the presence or absence of image defects. The image defects that occurred here are thought to be caused by the filler in the base layer of the fixing belt absorbing moisture and expanding, causing the circumference of the fixing belt to exceed the allowable range. Image defects were evaluated according to the following criteria. -standard- A: No image defects were observed on any of the 30 sheets. B: Image defects were observed on 1 or more but less than 10 sheets. C: Image defects were observed on 10 or more sheets.

[0162] <Lifespan evaluation> The fixing belt obtained in each example was installed in the fixing device of the image forming apparatus, and 10% halftone images were continuously output on A4 paper up to 1 million sheets. The presence or absence of fixing failure and gloss unevenness on the output image was checked every 100,000 sheets. Fixing failure and gloss unevenness here occur when the base layer of the fixing belt is torn or broken. The life was evaluated according to the following criteria. -standard- A: No poor fixing or uneven gloss was observed up to 1 million sheets. B: At least one of poor fixing and uneven gloss was observed at 700,000 or more and less than 1,000,000 sheets. C: At least one of poor fixing and uneven gloss was observed on less than 700,000 sheets.

[0163] [Table 1]

[0164] [Table 2]

[0165] From the above results, it can be seen that the base material layer (endless belt) of this example has higher insulation properties and thermal conductivity (specifically, thermal conductivity in the circumferential direction is 0.5 W / mK or more) and is also superior in bending durability compared to the base material layer (endless belt) of the comparative example. It can also be seen that the fixing belt of this example is superior to the fixing belt of the comparative example in all of fixing stability, reduction of FPOT, image defects, and lifespan. [Explanation of symbols]

[0166] 60 Fixing device 62 Pressure Belt 63 Belt guide 64 Pressure pad 64a Front clamping member 64b Peeling clamping member 65 Retaining member 66 Halogen lamp 68 Sliding member 69 Thermosensor 70 Peeling member 71 Peeling Nail 72 Retaining member 80 Fixing device 82 Sliding member 84 Heating Belt 86 Fuser belt module 88 Pressure Roll 89A halogen heater 89 Heated pressure roll 90A halogen heater 90 Support Roll 92A halogen heater 92 Support Roll 94 Posture Correction Roll 96 Support member 98 Support Roll 100 Image forming device 110 Fixing belt 110A base material 110B Elastic layer 110C surface layer

Claims

1. Resin and Thermal conductivity is 220 W / mK or more and 320 W / mK or less, and volume resistivity is 10 １１ Ωcm or more 10 １６ Ωcm or less, an aspect ratio of 55 to 2170, and a content of needle filler in the endless belt of 3% by mass to 30% by mass, the needle-like filler particles are oriented in the circumferential direction of the endless belt, and the orientation rate of the needle-like filler particles in the circumferential direction of the endless belt is 70% or more. Endless belt.

2. The thermal conductivity of the endless belt in the circumferential direction is 0.5 W / mK or more and 3.0 W / mK or less, and the volume resistivity is 10 １３ Ωcm or more 10 １６ 2. The endless belt according to claim 1, wherein the elastic modulus is Ωcm or less.

3. a resin; and needle fillers having an aspect ratio of 55 to 2170, the content of which is 1% by mass to 30% by mass relative to the endless belt, The thermal conductivity in the circumferential direction is 1.0 W / mK or more and 3.0 W / mK or less, and the volume resistivity is 10 １３ Ωcm or more 10 １６ An endless belt with a resistance of Ωcm or less.

4. The needle-like filler has a thermal conductivity of 220 W / mK or more and 320 W / mK or less and a volume resistivity of 10 １１ Ωcm or more 10 １６ 4. The endless belt according to claim 3, wherein the elastic modulus is Ωcm or less.

5. 5. The endless belt according to claim 3, wherein the needle filler particles are oriented in the circumferential direction of the endless belt.

6. 6. The endless belt according to claim 5, wherein the needle filler has an orientation rate of 70% or more in the circumferential direction of the endless belt.

7. 7. The endless belt according to claim 1, wherein the needle-like filler particles are aluminum nitride single crystals.

8. Resin and Thermal conductivity is 220 W / mK or more and 320 W / mK or less, and volume resistivity is 10 １１ Ωcm or more 10 １６ Ωcm or less, an aspect ratio of 55 to 2170, and a content of needle filler in the endless belt of 1% by mass to 30% by mass, The needle-like filler is an aluminum nitride single crystal. Endless belt.

9. a resin; and needle fillers having an aspect ratio of 55 to 2170, the content of which is 1% by mass to 30% by mass relative to the endless belt, the needle-like filler is an aluminum nitride single crystal, The thermal conductivity in the circumferential direction is 0.5 W / mK or more and 3.0 W / mK or less, and the volume resistivity is 10 １３ Ωcm or more 10 １６ An endless belt with a resistance of Ωcm or less.

10. 10. The endless belt according to claim 1, wherein the length of the needle filler is 100 μm or more and 6000 μm or less.

11. 11. The endless belt according to claim 10, wherein the diameter of the needle filler is 1 μm or more and 4 μm or less.

12. 12. The endless belt according to claim 1, wherein the aspect ratio of the needle filler is 100 or more and 2,000 or less.

13. A fixing belt comprising: the endless belt according to any one of claims 1 to 12; and a surface layer provided on an outer peripheral surface of the endless belt.

14. 14. The fixing belt according to claim 13, further comprising an elastic layer provided between the endless belt and the surface layer.

15. The elastic layer has a thermal conductivity of 220 W / mK or more and 320 W / mK or less, a volume resistivity of 10 １１ Ωcm or more 10 １６ 15. The fixing belt according to claim 14, comprising a needle filler having a resistance of Ωcm or less.

16. 16. The fixing belt according to claim 15, wherein the needle filler contained in the elastic layer is aluminum nitride single crystal.

17. a first rotating body formed of the fixing belt according to any one of claims 13 to 16; a second rotor disposed in contact with an outer peripheral surface of the first rotor; a pressing member disposed inside the first rotating body and pressing the first rotating body against the second rotating body from an inner peripheral surface of the first rotating body; A fixing device comprising:

18. an image carrier; a charging device for charging the surface of the image carrier; a latent image forming device for forming a latent image on the charged surface of the image carrier; a developing device that develops the latent image with toner to form a toner image; a transfer device that transfers the toner image onto a recording medium; a fixing device according to claim 17 for fixing the toner image onto a recording medium; An image forming apparatus comprising:

Images