Endless belt, heat-sealing device, fixing device, and article conveying device

Abstract

Provided are a belt, a heat-sealing device, a fixing device, and an article conveying device. The belt has a base material layer and a surface layer formed of a cross-linked fluororesin layer provided on an outer circumferential surface of the base material layer, an inner circumferential surface of the belt is composed of a layer containing a cross-linked fluororesin, and the Martens hardness of the inner circumferential surface of the belt at 130°C is higher than the Martens hardness of the outer circumferential surface of the belt at 130°C.

Description

TECHNICAL FIELD

[0001] The present application relates to a loop belt, a heat-sealing device, a fixing device, and an article conveying device. BACKGROUND

[0002] Japanese Patent Application Publication No. 2018-185007 discloses "a sliding member, which is a sliding member provided with a base material and a fluororesin layer having fluororesin as a main component, wherein the fluororesin layer includes a fusion layer having low cross-linking degree". SUMMARY

[0003] PROBLEMS TO BE SOLVED BY THE INVENTION

[0004] For a loop belt used in a device that heats a heated body while conveying the heated body, in addition to the requirement for wear resistance of the loop belt, the loop belt is required to easily follow the unevenness of the heated body.

[0005] The present application relates to a loop belt, a heat-sealing device, a fixing device, and an article conveying device.

[0006] MEANS FOR SOLVING THE PROBLEMS

[0007] According to a first aspect of the present application, there is provided a loop belt, comprising:

[0008] a base material layer, and

[0009] a surface layer provided on an outer circumferential surface of the base material layer, formed of a cross-linked fluororesin layer,

[0010] an inner circumferential surface of the belt is composed of a layer containing cross-linked fluororesin,

[0011] a Martens hardness of the inner circumferential surface of the belt at 130°C is higher than a Martens hardness of the outer circumferential surface of the belt at 130°C.

[0012] According to a second aspect of the present application, the Martens hardness of the outer circumferential surface of the belt at 130°C is 2 N / mm 2 or more and 10 N / mm 2 or less. 2 or more and 12 N / mm 2 or less.

[0013] According to a 3rd aspect of the present application, the difference between the Martens hardness of the outer peripheral surface at 130°C and the Martens hardness of the inner peripheral surface at 130°C is 2 N / mm 2 or more than 10 N / mm 2 or more than 10 N / mm

[0014] According to a 4th aspect of the present application, as the layer containing the crosslinked fluororesin, a crosslinked fluororesin layer is provided on the inner peripheral surface of the substrate layer.

[0015] According to a 5th aspect of the present application, the layer containing the crosslinked fluororesin is the substrate layer containing crosslinked fluororesin particles.

[0016] According to a 6th aspect of the present application, the Martens hardness of the inner peripheral surface at 25°C is lower than the Martens hardness of the outer peripheral surface at 25°C.

[0017] According to a 7th aspect of the present application, the Martens hardness of the outer peripheral surface at 25°C is 15 N / mm 2 or more than 23 N / mm 2 or more than 23 N / mm 2 or more than 19 N / mm 2 or more than 19 N / mm

[0018] According to an 8th aspect of the present application, the difference between the Martens hardness of the outer peripheral surface at 25°C and the Martens hardness of the inner peripheral surface at 25°C is 2 N / mm 2 or more than 10 N / mm 2 or more than 10 N / mm

[0019] According to a 9th aspect of the present application, the crosslinked fluororesin contained in the surface layer is a perfluoroalkyl vinyl ether-tetrafluoroethylene copolymer resin, and the crosslinked fluororesin contained in the layer constituting the inner peripheral surface is a polytetrafluoroethylene resin.

[0020] According to a 10th aspect of the present application, there is provided a heat-sealing device comprising:

[0021] a 1st rotating body,

[0022] a 2nd rotating body disposed in contact with the outer surface of the 1st rotating body, formed of the endless belt, and

[0023] a pressing member disposed inside the 2nd rotating body, pressing the 2nd rotating body toward the 1st rotating body from the inner surface of the 2nd rotating body.

[0024] According to an 11th aspect of the present application, there is provided a fixing device comprising:

[0025] a 1st rotating body,

[0026] a second rotating body disposed in contact with the outer surface of the first rotating body, formed of the endless belt, and

[0027] a pressing member disposed inside the second rotating body, pressing the second rotating body toward the first rotating body from the inner surface of the second rotating body.

[0028] According to a twelfth aspect of the present application, there is provided an article conveying apparatus including:

[0029] an article conveying belt formed of the endless belt, and

[0030] a heating source that heats a heated body conveyed by the article conveying belt.

[0031] Effects of the Invention

[0032] According to the first, fourth, fifth, or ninth aspect described above, the outer peripheral surface and the inner peripheral surface of the endless belt of the belt according to the aspect have wear resistance, and the outer peripheral surface has excellent unevenness followability, as compared with an endless belt having a base material layer and a surface layer formed of a crosslinked fluororesin layer provided on the outer peripheral surface of the base material layer, an inner peripheral surface of the belt composed of a layer containing a crosslinked fluororesin, and a Martens hardness of the inner peripheral surface of the belt at 130°C lower than a Martens hardness of the outer peripheral surface of the belt at 130°C.

[0033] According to the second aspect described above, the outer peripheral surface and the inner peripheral surface of the endless belt of the belt according to the aspect have wear resistance, and the outer peripheral surface has excellent unevenness followability, as compared with a case where a Martens hardness of the outer peripheral surface of the belt at 130°C is greater than 10 N / mm 2 or a Martens hardness of the inner peripheral surface of the belt at 130°C is less than 4 N / mm 2 .

[0034] According to the third aspect described above, the outer peripheral surface and the inner peripheral surface of the endless belt of the belt according to the aspect have wear resistance, and the outer peripheral surface has excellent unevenness followability, as compared with a case where a difference between a Martens hardness of the outer peripheral surface of the belt at 130°C and a Martens hardness of the inner peripheral surface of the belt at 130°C is less than 2 N / mm 2 or greater than 10 N / mm 2 .

[0035] According to the sixth aspect described above, the outer peripheral surface and the inner peripheral surface of the endless belt of the belt according to the aspect have wear resistance, and a load at the start of rotation is suppressed, as compared with a case where a Martens hardness of the inner peripheral surface of the belt at 25°C is higher than a Martens hardness of the outer peripheral surface of the belt at 25°C.

[0036] According to the seventh aspect described above, the outer peripheral surface and the inner peripheral surface of the endless belt of the belt according to the aspect have wear resistance, and a load at the start of rotation is suppressed, as compared with a case where a Martens hardness of the outer peripheral surface of the belt at 25°C is less than 15 N / mm2 or the Martens hardness of the outer peripheral surface of the belt is greater than 19 N / mm at 25°C 2 The outer peripheral surface and the inner peripheral surface of the endless belt of the present embodiment have wear resistance, and the load at the start of rotation is suppressed, compared to the case where

[0037] According to the above-described 8th aspect, there is provided an endless belt, the difference between the Martens hardness of the outer peripheral surface of the belt at 25°C and the Martens hardness of the inner peripheral surface of the belt at 25°C is less than 2 N / mm 2 or greater than 10 N / mm 2 The outer peripheral surface and the inner peripheral surface of the endless belt of the present embodiment have wear resistance, and the load at the start of rotation is suppressed, compared to the case where

[0038] According to the above-described 10th, 11th, or 12th aspect, there is provided a heat-sealing device, a fixing device, or an article conveying device provided with an endless belt, the outer peripheral surface and the inner peripheral surface of the endless belt of the present embodiment have wear resistance, and the concave-convex followability of the outer peripheral surface is excellent, compared to the case where the endless belt has a substrate layer, a surface layer formed of a crosslinked fluororesin layer provided on the outer peripheral surface of the substrate layer, the inner peripheral surface of the belt is composed of a layer containing a crosslinked fluororesin, and the Martens hardness of the inner peripheral surface at 130°C is lower than the Martens hardness of the outer peripheral surface at 130°C. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 is a schematic cross-sectional view showing an example of the layer constitution of the endless belt of the present embodiment.

[0040] Figure 2 is a schematic cross-sectional view showing another example of the layer constitution of the endless belt of the present embodiment.

[0041] Figure 3 is a schematic view showing one configuration example of the heat-sealing device of the present embodiment.

[0042] Figure 4 is a schematic view showing one configuration example of the fixing device of the present embodiment.

[0043] Figure 5 is a schematic view showing one configuration example of the article conveying device of the present embodiment. DETAILED DESCRIPTION

[0044] The present embodiment will be described below. These descriptions and examples serve to exemplify the embodiment, and do not limit the scope of the embodiment.

[0045] In the numerical range described in stages in the present embodiment, the upper limit value or the lower limit value described in one numerical range can be replaced with the upper limit value or the lower limit value of the numerical range described in another stage. In addition, in the numerical range described in the present embodiment, the upper limit value or the lower limit value of the numerical range can be replaced with the value shown in the examples.

[0046] The term "step" in the present embodiment includes not only a separate step but also a step that can achieve the intended purpose even if it cannot be clearly distinguished from other steps.

[0047] In the description of the embodiments in the present embodiment with reference to the drawings, the configuration of the embodiments is not limited to the configuration shown in the drawings. In addition, the size of the components in each drawing is illustrative, and the relative relationship of the sizes between the components is not limited thereto.

[0048] Each component in the present embodiment can include two or more corresponding substances. In the case where the amount of each component in the composition in the present embodiment is mentioned, in the case where two or more substances corresponding to each component exist in the composition, the total amount of the two or more substances existing in the composition is meant unless specifically stated.

[0049] [Endless belt]

[0050] The endless belt of the present embodiment has a substrate layer and a surface layer provided on the outer circumferential surface of the substrate layer and formed of a crosslinked fluororesin layer, the inner circumferential surface of the belt is composed of a layer containing a crosslinked fluororesin, and the Martens hardness of the inner circumferential surface of the belt at 130°C is higher than the Martens hardness of the outer circumferential surface of the belt at 130°C.

[0051] Hereinafter, the Martens hardness of the outer circumferential surface of the belt at 130°C is also referred to as "HMo(130°C)", and the Martens hardness of the inner circumferential surface of the belt at 130°C is also referred to as "HMi(130°C)".

[0052] In the endless belt of the present embodiment, the surface layer provided on the outer circumferential surface of the substrate layer is formed of a crosslinked fluororesin layer, the inner circumferential surface of the belt contains a crosslinked fluororesin, and HMi(130°C) is higher than HMo(130°C), whereby the outer circumferential surface and the inner circumferential surface of the belt have wear resistance, and the outer circumferential surface has excellent concave-convex followability. The reason is not yet determined, but it is presumed as follows.

[0053] In a device in which a heated body provided on an endless belt is heated and at the same time conveyed (for example, a heat-sealing device, a fixing device, an article conveying device, or the like), for example, in a state in which the endless belt is heated, the outer circumferential surface of the belt contacts the heated body or the like, and the inner circumferential surface of the belt slides against other members such as a heating member.

[0054] Therefore, for example, if the above-described apparatus is continuously operated, the outer circumferential surface and the inner circumferential surface of the endless belt can be abraded. When the outer circumferential surface of the endless belt is abraded, the surface thereof becomes rough, and thus uneven heating of the heated object can be caused. In addition, when the inner circumferential surface of the endless belt is abraded, for example, an endless belt abrasion powder is generated, and thus the rotational load of the endless belt can be increased.

[0055] However, if the hardness of the outer circumferential surface and the inner circumferential surface of the endless belt is increased, the abrasion can be suppressed, but on the other hand, the unevenness following property of the endless belt is decreased, and the endless belt is difficult to follow the shape of the heated object, and thus uneven heating of the heated object can be caused.

[0056] Therefore, an endless belt in which all of these properties are good is being sought. In particular, in an apparatus in which a heated object arranged on an endless belt is heated and pressed and is simultaneously conveyed, an endless belt in which the hardness of the outer circumferential surface and the inner circumferential surface and the unevenness following property can be balanced is further required.

[0057] On the contrary, in the present embodiment, the surface layer provided on the outer circumferential surface of the base material layer is formed of a crosslinked fluororesin layer, the inner circumferential surface of the belt includes a crosslinked fluororesin, and HMi(130°C) is higher than HMo(130°C). Therefore, by forming the surface layer of the crosslinked fluororesin layer, the abrasion resistance of the outer circumferential surface of the belt can be ensured, and in a state in which the endless belt is heated due to the operation of the apparatus, the abrasion resistance of the inner circumferential surface of the belt which slides against other members can also be obtained due to the high hardness of the inner circumferential surface of the belt. It can also be inferred that, in a state in which the endless belt is heated, the outer circumferential surface of the belt easily follows the shape of the heated object because the hardness of the outer circumferential surface of the belt is relatively lower than that of the inner circumferential surface of the belt, and the abrasion resistance and the unevenness following property can be balanced.

[0058] It can be inferred from the above reasons that, in the present embodiment, the outer circumferential surface and the inner circumferential surface of the endless belt have abrasion resistance, and the unevenness following property of the outer circumferential surface is excellent.

[0059] <Martens hardness>

[0060] Here, the Martens hardness is the hardness obtained by the nanoindentation method using a nanoindenter (HM500 manufactured by Fischer Instruments Corporation). Specifically, for the face of the measurement target in the sample of the measurement target, the measurement is performed on any three places at a specific measurement temperature (130°C or 25°C) under the conditions of a maximum indentation depth of 0.5 μm using a diamond Berkovich indenter, and the average value is calculated.

[0061] In the present embodiment, the Martens hardness of the inner circumferential surface of the belt at 130°C "HMi(130°C)" is higher than the Martens hardness of the outer circumferential surface of the belt at 130°C "HMo(130°C)".

[0062] As HMo (130°C), for example, 1 N / mm 2 The above 16 N / mm 2 The following range, from the aspect of taking into account wear resistance and concave-convex followability, is preferably 2 N / mm 2 The above 10 N / mm 2 The following range, more preferably 4 N / mm 2 The above 8 N / mm 2 The following range.

[0063] As HMi (130°C), for example, 1 N / mm 2 The above 16 N / mm 2 The following range, from the aspect of taking into account wear resistance and concave-convex followability, is preferably 4 N / mm 2 The above 12 N / mm 2 The following range, more preferably 6 N / mm 2 The above 10 N / mm 2 The following range.

[0064] The control of HMo (130°C) is performed, for example, by selecting the kind of crosslinked fluororesin constituting the surface layer, changing the ratio of the main component and the subcomponent of the crosslinked fluororesin of different kinds, adjusting the crosslinking degree of the crosslinked fluororesin, adjusting the time of the baking step in the process of manufacturing the resin before crosslinking, and the like. In addition, the control of HMi (130°C) is performed, for example, by the selection of the kind of the resin contained in the layer constituting the inner peripheral surface, the adjustment of the content of the crosslinked fluororesin, changing the ratio of the main component and the subcomponent of the crosslinked fluororesin of different kinds, adjusting the crosslinking degree of the crosslinked fluororesin, adjusting the time of the baking step in the process of manufacturing the resin before crosslinking, and the like.

[0065] Regarding the combination of HMo (130°C) and HMi (130°C), from the aspect of taking into account wear resistance and concave-convex followability, it is preferable that HMo (130°C) be 2 N / mm 2 The above 10 N / mm 2 The following range, and HMi (130°C) be 4 N / mm 2 The above 12 N / mm 2 The following range, more preferably HMo (130°C) be 4 N / mm 2 The above 8 N / mm 2 The following range, and HMi (130°C) be 6 N / mm 2 The above 10 N / mm 2 The following range.

[0066] Further, from the viewpoint of balancing the wear resistance and the unevenness followability, the difference between HMo(130°C) and HMi(130°C) is preferably 2 N / mm or more 2 The above 10 N / mm 2 The above range, more preferably 4 N / mm 2 The above 8 N / mm 2 The above range.

[0067] In the present embodiment, it is preferable that the Martens hardness at 25°C of the inner circumferential surface (hereinafter also referred to as "HMi(25°C)") be lower than the Martens hardness at 25°C of the outer circumferential surface (hereinafter also referred to as "HMo(25°C)").

[0068] By making HMi(130°C) higher than HMo(130°C) and making HMi(25°C) lower than HMo(25°C), in addition to the fact that the wear resistance and the unevenness followability can be balanced, the load applied at the start of rotation of the endless belt can also be suppressed. The reason for this is not clear, but it is presumed that, at the start of operation of the device, by making the hardness of the inner circumferential surface of the endless belt relatively low in a state in which the temperature of the endless belt is low, the load at the start of rotation of the endless belt can be absorbed by the inner circumferential surface.

[0069] As HMo(25°C), for example, 12 N / mm 2 The above 25 N / mm 2 The above range, from the viewpoint of balancing the wear resistance and the unevenness followability, preferably 15 N / mm 2 The above 23 N / mm 2 The above range, more preferably 17 N / mm 2 The above 21 N / mm 2 The above range.

[0070] As HMi(25°C), for example, 10 N / mm 2 The above 21 N / mm 2 The above range, from the viewpoint of balancing the wear resistance and the load suppression at the start of rotation, preferably 13 N / mm 2 The above 19 N / mm 2 The above range, more preferably 15 N / mm 2 The above 17 N / mm 2 The above range.

[0071] The control of HMo (25°C) can be performed, for example, by selecting the kind of the crosslinked fluororesin constituting the surface layer, changing the ratio of the main component to the subcomponent of the crosslinked fluororesin of different kinds, adjusting the crosslinking degree of the crosslinked fluororesin, adjusting the time of the baking step in the process of producing the resin before crosslinking, and the like. In addition, the control of HMi (25°C) can be performed, for example, by selecting the kind of the resin contained in the layer constituting the inner peripheral surface, adjusting the content of the crosslinked fluororesin, changing the ratio of the main component to the subcomponent of the crosslinked fluororesin of different kinds, adjusting the crosslinking degree of the crosslinked fluororesin, adjusting the time of the baking step in the process of producing the resin before crosslinking, and the like.

[0072] Regarding the combination of HMo (25°C) and HMi (25°C), from the viewpoint of balancing the wear resistance and the load reduction at the start of rotation, it is preferable that HMo (25°C) be 15 N / mm 2 23 N / mm 2 HMi (25°C) be 13 N / mm 2 19 N / mm 2 HMi (25°C) be 13 N / mm 2 21 N / mm 2 HMi (25°C) be 15 N / mm 2 17 N / mm 2 HMi (25°C) be 13 N / mm

[0073] In addition, from the viewpoint of balancing the wear resistance and the load reduction at the start of rotation, the difference between HMo (25°C) and HMi (25°C) is preferably 2 N / mm 2 10 N / mm 2 4 N / mm 2 8 N / mm 2 4 N / mm

[0074] <Layer Configuration>

[0075] The endless belt of the present embodiment will be described in detail below with reference to the drawings. Note that in the drawings, the same or corresponding portions are denoted by the same reference signs, and overlapping descriptions will be omitted.

[0076] Figure 1 is a schematic cross-sectional view showing an example of the endless belt of the present embodiment. Figure 2 is a schematic cross-sectional view showing another example of the endless belt of the present embodiment.

[0077] Figure 1The annular belt 1 shown, for example, is provided with a base material layer 2 containing crosslinked fluororesin particles and a surface layer 3 which is a crosslinked fluororesin layer in this order from the inner peripheral surface side. The surface layer 3 is the outermost layer constituting the outer peripheral surface of the annular belt 1.

[0078] Figure 2 The annular belt 11 shown, for example, is provided with a back surface layer 15 which is a crosslinked fluororesin layer, a base material layer 12, and a surface layer 13 which is a crosslinked fluororesin layer in this order from the inner peripheral surface side. The surface layer 13 is the outermost layer constituting the outer peripheral surface of the annular belt 11.

[0079] Note that, Figure 1 The annular belt 1 shown and Figure 2 The annular belt 11 shown can further have other layers as needed. As the other layers, for example, an adhesive layer provided between the base material layer and the surface layer, between the base material layer and the back surface layer, and the like can be given.

[0080] The layers constituting the annular belt of the present embodiment will be described below. Note that the description will be omitted for the symbols.

[0081] <Surface layer constituting the outer peripheral surface of the belt>

[0082] The surface layer is a layer provided on the outer peripheral surface of the base material layer and formed of a crosslinked fluororesin layer, and is a layer constituting the outer peripheral surface of the annular belt (i.e., the outermost layer). By making the layer constituting the outer peripheral surface of the belt a layer formed of a crosslinked fluororesin layer, the wear resistance of the outer peripheral surface of the belt is good, and the anti-sticking property of the heated body on the annular belt is also good.

[0083] Here, the surface layer which is a crosslinked fluororesin layer is a layer containing a crosslinked fluororesin as a main component, and can contain other components such as additives as needed. Among them, the content of the crosslinked fluororesin contained in the surface layer is preferably 80% by mass or more, more preferably 90% by mass or more, and further preferably 95% by mass or more.

[0084] (Crosslinked fluororesin)

[0085] As the crosslinked fluororesin, for example, a crosslinked body in which an uncrosslinked fluororesin is crosslinked by irradiating ionizing radiation (e.g., γ-rays, electron rays, X-rays, neutron rays, or high-energy ions, etc.) can be given. Specifically, as the crosslinked fluororesin, for example, a crosslinked body in which an uncrosslinked fluororesin in a state of being heated at a temperature higher than the crystalline melting point in an environment where oxygen is not present is crosslinked by irradiating ionizing radiation with a radiation dose of 1 KGy or more and 10 MGy or less can be given.

[0086] In addition, as the fluororesin, for example, polytetrafluoroethylene resin (hereinafter also referred to as "PTFE"), perfluoroalkyl vinyl ether-tetrafluoroethylene copolymer resin (hereinafter also referred to as "PFA"), tetrafluoroethylene-hexafluoropropylene copolymer resin (hereinafter also referred to as "FEP"), ethylene-tetrafluoroethylene copolymer resin (hereinafter also referred to as "ETFE"), and modified products thereof, and the like can be given.

[0087] From the viewpoint of balancing the wear resistance and the concave-convex followability, the crosslinked fluororesin contained in the surface layer is preferably PFA, PTFE, and FEP among these, and more preferably PFA.

[0088] In the present embodiment, as described above, the inner peripheral surface of the belt is a layer containing a crosslinked fluororesin. The kind of the crosslinked fluororesin contained in the surface layer can be the same as the kind of the crosslinked fluororesin contained in the layer constituting the inner peripheral surface of the belt, and from the viewpoint of setting HMi (130°C) higher than HMo (130°C), it is preferable that they be different.

[0089] From the viewpoint of balancing the wear resistance and the concave-convex followability, the combination of the crosslinked fluororesin contained in the surface layer and the crosslinked fluororesin contained in the layer constituting the inner peripheral surface of the belt is preferably a combination of at least one selected from the group consisting of PFA, PTFE, and FEP and at least one selected from the group consisting of PTFE, FEP, and FEP, and more preferably a combination of PFA and PTFE.

[0090] As the thickness of the surface layer, for example, 10 μm or more and 50 μm or less can be given, and from the viewpoint of maintaining the release property of the heated object, 20 μm or more and 40 μm or less are preferable, and 25 μm or more and 35 μm or less are more preferable.

[0091] From the viewpoint of maintaining the release property of the heated object, the thickness of the surface layer is preferably 11% or more and 38% or less of the thickness of the entire endless belt, and more preferably 20% or more and 33% or less, and further preferably 24% or more and 30% or less.

[0092] As a method of forming the surface layer, for example, a method in which an uncrosslinked fluororesin layer is formed on the outer peripheral surface of the base material layer, and then the fluororesin layer is crosslinked by irradiation with ionizing radiation to obtain a surface layer containing a crosslinked fluororesin can be given. Note that, as a method of forming the uncrosslinked fluororesin layer, for example, a method in which an uncrosslinked fluororesin film (film, tube, or the like) is arranged on the outer peripheral surface of the base material layer; a method in which a dispersion liquid containing an uncrosslinked fluororesin is applied to the outer peripheral surface of the base material layer and dried; and the like can be given. As a method of applying the dispersion liquid, known methods can be given, and specifically, for example, dip coating, spray coating, spiral coating (flow coating), blade coating, wire bar coating, microbead coating, air knife coating, curtain coating, and the like can be given. In addition, as a method of performing application and drying of the dispersion liquid, a centrifugal molding method and the like can be given.

[0093] <base material layer>

[0094] The material of the base material layer is not particularly limited, and, from the viewpoint of heat resistance and followability of the endless belt, for example, a heat-resistant resin can be given.

[0095] As the heat-resistant resin, for example, a polyimide resin (hereinafter also referred to as "PI"), a polyamide-imide resin (hereinafter also referred to as "PAI"), a polybenzimidazole resin (hereinafter also referred to as "PBI"), a polyether ether ketone resin (hereinafter also referred to as "PEEK"), a polysulfone resin (hereinafter also referred to as "PSU"), a polyether sulfone resin (hereinafter also referred to as "PES"), a polyphenylene sulfide resin (hereinafter also referred to as "PPS"), a polyetherimide resin (hereinafter also referred to as "PEI"), a wholly aromatic polyester resin, a fluororesin, and the like can be given.

[0096] Among them, as the material of the base material layer, from the viewpoint of mechanical strength and heat resistance, PI, PAI, PEI, and a fluororesin are preferable, PI and PAI are more preferable, and PI is further preferable.

[0097] As the thickness of the base material layer, for example, 20 μm or more and 200 μm or less can be given, and from the viewpoint of mechanical strength, 30 μm or more and 150 μm or less are preferable, and 40 μm or more and 130 μm or less are more preferable.

[0098] As a method of forming the base material layer, for example, a method in which a dispersion liquid containing a heat-resistant resin or a precursor of a heat-resistant resin is applied to the outer peripheral surface of the base and dried, and firing is performed as necessary, thereby obtaining a base material layer containing a heat-resistant resin; and a method in which a base material layer containing a heat-resistant resin is obtained by injection molding, extrusion molding, mold casting, or the like can be given. Note that the method of applying the dispersion liquid, and the specific examples of the method of applying and drying the dispersion liquid are the same as those described above in the formation of the surface layer.

[0099] (Base material layer constituting the outer peripheral surface of the belt)

[0100] In the case where the base material layer is a layer constituting the outer peripheral surface of the belt, the base material layer contains at least a cross-linked fluororesin. In the case where the base material layer is a layer constituting the outer peripheral surface of the belt, the base material layer is preferably a layer containing the above-mentioned heat-resistant resin and a cross-linked fluororesin, and more preferably a layer containing cross-linked fluororesin particles in the above-mentioned heat-resistant resin.

[0101] Specific examples of the cross-linked fluororesin contained in the base material layer constituting the outer peripheral surface of the belt can be given as the same examples as those of the cross-linked fluororesin contained in the surface layer described above. Among them, from the viewpoint of balancing the wear resistance and the concave-convex followability, the cross-linked fluororesin contained in the base material layer constituting the outer peripheral surface of the belt is preferably PTFE, PFA, FEP, and more preferably PTFE.

[0102] Regarding the combination of the heat-resistant resin and the cross-linked fluororesin, from the viewpoint of the wear resistance and the heat resistance, a combination of at least one selected from the group consisting of PI and PAI and at least one selected from the group consisting of PTFE, PFA, and FEP is preferable, and a combination of PI and PTFE is more preferable.

[0103] In the case where the base material layer is a layer constituting the outer peripheral surface of the belt, as the content of the cross-linked fluororesin in the base material layer, for example, a range of 5% by mass or more and 60% by mass or less can be given, and from the viewpoint of balancing the wear resistance and the heat resistance and the mechanical strength as a base material, a range of 10% by mass or more and 40% by mass or less is preferable, and a range of 15% by mass or more and 25% by mass or less is more preferable.

[0104] In addition, in the case where the base material layer is a layer containing cross-linked fluororesin particles in the heat-resistant resin, as the number average particle diameter of the cross-linked fluororesin particles, for example, a range of 0.05 μm or more and 1 μm or less can be given, and from the viewpoint of balancing the wear resistance and the heat resistance and the mechanical strength as a base material, a range of 0.07 μm or more and 0.5 μm or less is preferable, and a range of 0.1 μm or more and 0.3 μm or less is more preferable.

[0105] The number average particle diameter of the cross-linked fluororesin particles is a value measured by the following method.

[0106] First, the layer contained in the crosslinked fluororesin particles is cut to produce a test piece. The cross section of the obtained test piece is observed by SEM (scanning electron microscope) at, for example, a magnification of 5,000 times or more, and the maximum diameter of the crosslinked fluororesin particles in the primary particle state is measured for 50 particles. The average of the maximum diameters of the 50 crosslinked fluororesin particles in the primary particle state is taken as the number average particle diameter. Note that, as the SEM, a JSM-6700F manufactured by JEOL Ltd. is used, and a secondary electron image at an acceleration voltage of 5 kV is observed.

[0107] Note that, in the case where the base material layer containing the crosslinked fluororesin particles in the heat-resistant resin is formed, crosslinked fluororesin particles that have been crosslinked in advance before the base material layer is produced can be used, or the fluororesin particles can be crosslinked by irradiation with ionizing radiation after the base material layer containing the uncrosslinked fluororesin particles is formed. As a method of forming the base material layer containing the crosslinked fluororesin particles in the heat-resistant resin, for example, a method in which a dispersion liquid containing crosslinked fluororesin particles that have been crosslinked in advance and a heat-resistant resin or a precursor of the heat-resistant resin is applied to the outer circumferential surface of a base, the applied film is dried, and, as necessary, firing is performed, thereby obtaining a base material layer containing the crosslinked fluororesin and the heat-resistant resin; a method in which a dispersion liquid containing uncrosslinked fluororesin particles and a heat-resistant resin or a precursor of the heat-resistant resin is applied to the outer circumferential surface of a base, the applied film is dried, and, as necessary, firing is performed, thereby obtaining a base material layer containing the uncrosslinked fluororesin and the heat-resistant resin, and then ionizing radiation is irradiated; a method in which crosslinked fluororesin particles that have been crosslinked in advance and a heat-resistant resin are mixed by kneading or the like to perform molding, thereby obtaining a base material layer containing the crosslinked fluororesin and the heat-resistant resin; a method in which uncrosslinked fluororesin particles and a heat-resistant resin are mixed by kneading or the like to perform molding, thereby obtaining a base material layer containing the uncrosslinked fluororesin and the heat-resistant resin, and then ionizing radiation is irradiated; and the like can be given.

[0108] <Back surface layer constituting the inner circumferential surface of the belt>

[0109] In the case where the base material layer does not constitute the layer constituting the inner circumferential surface of the belt, the endless belt has a back surface layer on the inner circumferential surface of the base material layer. The back surface layer is the layer constituting the inner circumferential surface of the belt (i.e., the innermost layer). The back surface layer is a layer containing at least the crosslinked fluororesin, and is preferably a crosslinked fluororesin layer.

[0110] The back surface layer as the crosslinked fluororesin layer is a layer containing the crosslinked fluororesin as a main component, and can contain other components such as additives as necessary. Among them, the content of the crosslinked fluororesin contained in the back surface layer is preferably 80% by mass or more, more preferably 90% by mass or more, and further preferably 95% by mass or more.

[0111] Specific examples of the crosslinked fluororesin contained in the back surface layer can be the same examples as those of the crosslinked fluororesin contained in the surface layer described above. Among them, from the viewpoint of balancing the wear resistance and the unevenness followability, the crosslinked fluororesin contained in the back surface layer is preferably PTFE, PFA, FEP, and more preferably PTFE.

[0112] As the thickness of the back surface layer, for example, 2 μm or more and 40 μm or less can be given, and from the viewpoint of maintaining the slidability of the endless belt, 5 μm or more and 30 μm or less, and more preferably 10 μm or more and 20 μm or less are preferable.

[0113] From the viewpoint of maintaining the slidability of the endless belt, the thickness of the back surface layer is preferably 1.7% or more and 27% or less of the thickness of the entire endless belt, more preferably 4.3% or more and 21% or less, and further preferably 8% or more and 15% or less.

[0114] As the method of forming the back surface layer, for example, the method of forming the uncrosslinked fluororesin layer on the inner peripheral surface of the base material layer and then irradiating ionizing radiation, and the like can be given similarly to the method of forming the surface layer described above. Note that the specific examples of the method of applying the dispersion liquid and the method of applying and drying the dispersion liquid are the same as those in the formation of the surface layer described above.

[0115] [Heat sealing device]

[0116] The heat sealing device of the present embodiment includes: a first rotary body; a second rotary body disposed in contact with the outer surface of the first rotary body; and a pressing member disposed inside the second rotary body, which presses the second rotary body toward the first rotary body from the inner surface of the second rotary body, and the above-described endless belt is used as the second rotary body.

[0117] In the heat sealing device, for example, a heated body is heated and pressurized in the sandwiched region between the first rotary body and the second rotary body. Specifically, for example, in the case where a laminate in which a sealing portion is in contact and overlapped is used as the heated body, when the laminate passes through the sandwiched region between the first rotary body and the second rotary body in the heat sealing device, the laminate is heated and pressurized, thereby causing the sealing portion of the laminate to be bonded.

[0118] Note that the heating source that heats the heated body passing through the sandwiched region between the first rotary body and the second rotary body can be disposed inside the first rotary body, can be disposed inside the second rotary body, can be disposed outside the first rotary body and the second rotary body, or can be disposed at multiple positions. In addition, the pressing member and other members disposed inside the second rotary body can also function as the heating source.

[0119] An example of the heat-sealing device of the present embodiment will be described below, but is not limited thereto.

[0120] Figure 3 A schematic configuration diagram of an example of the heat-sealing device of the present embodiment is shown. Figure 3 A heat-sealing device provided with the above-described endless belt as a sealing belt.

[0121] Figure 3 The heat-sealing device 400 shown in the configuration includes a sealing belt 410 as an example of a first rotary body, a sealing belt 430 as an example of a second rotary body using the above-described endless belt, and a heating block 440 as an example of a pressing member provided inside the sealing belt 430.

[0122] Note that in the heat-sealing device 400, the sealing belt 410 as the first rotary body also uses the above-described endless belt as with the sealing belt 430, and a heating block 420 that functions as a pressing member is provided inside the sealing belt 410.

[0123] Here, the heating block 420 and the heating block 440 each also have a function of a heating source that heats a heated body passing through a sandwiched region between the sealing belt 410 and the sealing belt 430.

[0124] The sealing belt 410 is supported so as to be freely rotatable by a drive roller 411 and a support roller 412 inside and by the heating block 420, and is arranged in a state in which the heating block 420 presses the sealing belt 430.

[0125] Similarly, the sealing belt 430 is supported so as to be freely rotatable by a drive roller 431 and a support roller 432 inside and by the heating block 440, and is arranged in a state in which the heating block 440 presses the sealing belt 410.

[0126] Thus, a sandwiched region in which a heated body is sandwiched is formed between the sealing belt 410 and the sealing belt 430.

[0127] The heating block 420 and the heating block 440 are resistance heating elements as an example of a heating source, and supply heat to the sandwiched region. That is, the heating block 420 and the heating block 440 are pressing members that press the sealing belt 410 and the sealing belt 430, respectively, from the inside toward the sandwiched region, and also have a function as a heating source that heats a heated body passing through the sandwiched region.

[0128] Note that in the heat-sealing device 400, the heating block 420 and the heating block 440 as the pressing members also function as the heating source, but are not limited thereto, and the heating source can be provided in the form of a member separate from the pressing members. As the heating source that is a member separate from the pressing members, for example, a carbon heater or the like that heats by radiating heat can be cited.

[0129] A lubricant applying member, not shown, is provided to the inner circumferential surface of the sealing tape 410 and the sealing tape 430. The lubricant applying member is arranged, for example, in contact with the inner circumferential surface of the sealing tape, and supplies the inner circumferential surface of the sealing tape with an appropriate amount of lubricant.

[0130] As the lubricant, for example, fluorine oil, silicone oil, synthetic lubricating grease in which a solid substance is mixed with a liquid, and the like can be given.

[0131] As the fluorine oil, for example, perfluoropolyether oil, modified perfluoropolyether oil, and the like can be given.

[0132] As the silicone oil, for example, dimethyl silicone oil, dimethyl silicone oil to which an organometallic salt is added, dimethyl silicone oil to which a hindered amine is added, dimethyl silicone oil to which an organometallic salt and a hindered amine are added, methylphenyl silicone oil, amino-modified silicone oil, amino-modified silicone oil to which an organometallic salt is added, amino-modified silicone oil to which a hindered amine is added, carboxyl-modified silicone oil, silanol-modified silicone oil, sulfonic acid-modified silicone oil, and the like can be given.

[0133] As the synthetic lubricating grease, for example, silicone grease (i.e., a lubricant containing the above-described silicone oil), fluorine grease (i.e., a lubricant containing the above-described fluorine oil), and the like can be given.

[0134] From the viewpoint of wear resistance of the inner circumferential surface of the tape, the lubricant is preferably one containing a fluorine atom among these, more preferably a lubricant containing fluorine oil (i.e., fluorine oil and fluorine grease), and further preferably a lubricant containing perfluoropolyether oil (i.e., perfluoropolyether oil alone and a lubricant containing perfluoropolyether oil).

[0135] Note that, in the heat sealing device 400, the inner circumferential surface of the sealing tape is supplied with the lubricant by the lubricant applying member, but the form in which the lubricant applying member and the lubricant are not used can also be employed.

[0136] In the heat sealing device 400, first, the sealing tape 430 is rotated in the arrow A direction by the rotational drive of the drive roller 431, whereby the laminate 450, which is a heated body with the sealing portion overlaid, is moved on the sealing tape 430 in the arrow C direction and introduced into the sandwiching region. On the other hand, the sealing tape 410 is rotated in the arrow B direction by the rotational drive of the drive roller 411.

[0137] The laminate 450 conveyed to the sandwiching region is conveyed by the rotation of the sealing tape 410 and the sealing tape 430 and simultaneously heated and pressurized by the heat blocks 420 and 440, so that the sealing portion of the laminate 450 is bonded.

[0138] After that, the laminate 450 whose sealing portion is bonded is further conveyed by the rotation of the sealing tape 430 and discharged from the sandwiching region.

[0139] [Fixing device]

[0140] The fixing device of the present embodiment is provided with: a first rotating body; a second rotating body disposed in contact with the outer surface of the first rotating body; and a pressing member disposed inside the second rotating body, which presses the second rotating body toward the first rotating body from the inner surface of the second rotating body, and uses the above-mentioned endless belt as the second rotating body.

[0141] In the fixing device, the heated body is heated and pressed at the contact portion of the first rotating body and the second rotating body, for example, by a heating source. Specifically, for example, in the case where the recording medium on which the un-fixed toner image is formed is used as the heated body, when the recording medium on which the un-fixed toner image is formed passes through the contact portion of the first rotating body and the second rotating body in the fixing device, the recording medium is heated and pressed, thereby fixing the toner image to the recording medium.

[0142] Note that the heating source that heats the heated body that passes through the contact portion of the first rotating body and the second rotating body can be disposed inside the first rotating body, can be disposed inside the second rotating body, can be disposed outside the first rotating body and the second rotating body, or can be disposed at multiple locations. In addition, the pressing member and other members disposed inside the second rotating body can also function as the heating source.

[0143] An example of the fixing device of the present embodiment will be described below, but is not limited thereto.

[0144] Figure 4 A schematic configuration diagram of an example of the fixing device of the present embodiment is shown. Figure 4 A fixing device provided with the above-mentioned endless belt as a fixing belt.

[0145] Figure 4 The configuration of the fixing device 900 shown is provided with: a pressure roller 910 as an example of the first rotating body, a fixing belt 920 as an example of the second rotating body using the above-mentioned endless belt, and a ceramic heater 820 as an example of the pressing member. Note that the ceramic heater 820 also has the function of a heating source that heats the heated body that passes through the contact portion of the pressure roller 910 and the fixing belt 920.

[0146] The pressure roller 910 is a rotating body that is rotationally driven. The pressure roller 910 is disposed in a manner corresponding to the fixing belt 920, is rotated in the arrow D direction by a not-shown drive motor, and the fixing belt 920 is driven to rotate in a direction opposite to the rotation direction of the pressure roller 910.

[0147] The pressure roller 910 is, for example, configured by stacking a core (cylindrical core rod) 911, a heat-resistant elastic layer 912 coated on the outer circumferential surface of the core 911, and a release layer 913 coated with a heat-resistant resin or a heat-resistant rubber. Each layer constituting the pressure roller 910 is made semi-conductive by adding carbon black or the like as needed to cope with offset of toner.

[0148] The fixing belt 920 is disposed on the side of the non-fixed toner image holding surface of the paper sheet K as a heated body. The fixing belt 920 is rotatably supported by the ceramic heater 820, the belt stroke guide 630, and an unillustrated edge guide inside. It is disposed in contact with the pressure roller 910 in a state of being pressed by the pressure roller 910 in the pinch area N. Note that the ceramic heater 820 and the belt stroke guide 630 are held by a metal-made holder 650. The belt stroke guide 630 is formed of a material (e.g., PFA, PPS, or the like) having a small static friction coefficient and a low thermal conductivity, for example.

[0149] The ceramic heater 820 is disposed inside the fixing belt 920 in a state of pressing the pressure roller 910 across the fixing belt 920, forming a pinch area N between itself and the pressure roller 910. In the ceramic heater 820, the side of the pressure roller 910 is formed as a flat surface, for example.

[0150] The ceramic heater 820 is a resistance heating body as an example of a heating source, and supplies heat to the pinch area N. Note that in the fixing device 900, the ceramic heater 820 as a pressing member also functions as a heating source, but is not limited thereto, and a heating source can be provided in the form of a member separate from the pressing member. As the heating source as a member separate from the pressing member, for example, a halogen lamp provided inside the fixing belt 920, an electromagnetic induction coil provided inside or outside the fixing belt 920, or the like can be given.

[0151] In the holder 650, a lubricant application member 670 is disposed along the length direction of the fixing device 900. The lubricant application member 670 is disposed in contact with the inner circumferential surface of the fixing belt 920, and supplies an appropriate amount of lubricant to the inner circumferential surface of the fixing belt 920.

[0152] As specific examples and preferable examples of the lubricant, the same as the specific examples and preferable examples of the lubricant used in the heat-sealing device described above can be given.

[0153] Note that in the fixing device 900, the lubricant is supplied to the inner circumferential surface of the fixing belt 920 by the lubricant application member 670, but a configuration in which the lubricant application member and the lubricant are not used can also be given.

[0154] In the fixing device 900, as an assisting mechanism for peeling, a peeling member 700 is provided on the downstream side of the nip region N of the fixing belt 920. The peeling member 700 is held by a holder 720 in a state in which a peeling baffle 710 is close to the fixing belt 920 in a direction opposite to the rotation direction of the fixing belt 920 (the opposite direction).

[0155] In the fixing device 900, first, the paper sheet K having the un-fixed toner image as the heated body is guided by the fixing inlet guide 560 and conveyed toward the nip region N. The paper sheet K conveyed to the nip region N is conveyed by the rotation of the pressure roller 910 and the fixing belt 920 and passes through the nip region N. Also, when the paper sheet K passes through the nip region N, the toner image on the paper sheet K is fixed under the action of the pressure applied to the nip region N and the heat supplied from the ceramic heater 820.

[0156] The paper sheet K that has passed through the nip region N is peeled from the fixing belt 920 at the exit region (the peeling nip) of the nip region N due to the change in the curvature of the fixing belt 920.

[0157] [Article conveying device]

[0158] The article conveying device of the present embodiment is provided with an article conveying belt formed of the above-described endless belt, and a heating source that heats a heated body conveyed by the article conveying belt.

[0159] In the article conveying device, for example, an article as the heated body is heated by the heating source while being conveyed by the article conveying belt. The article as the heated body is not particularly limited, and for example, food, electronic components, and the like can be cited.

[0160] Note that the heating source that heats the heated body conveyed by the article conveying belt can be arranged inside the article conveying belt, can be arranged outside the article conveying belt, or can be arranged at a plurality of positions.

[0161] In addition, the article conveying device can be a device that presses and simultaneously heats the heated body conveyed by the article conveying belt.

[0162] An example of the article conveying device of the present embodiment will be described below, but is not limited thereto.

[0163] Figure 5 A schematic configuration diagram of an example of the article conveying device of the present embodiment is shown. Figure 5 An article conveying device provided with the above-described endless belt as an article conveying belt.

[0164] Figure 5The article conveying device 300 shown includes a conveyor belt 310 as an example of an article conveying belt using the endless belt described above, and a heating block 320 as an example of a heating source provided inside the conveyor belt 310.

[0165] The conveyor belt 310 is configured with a drive roller 311 and a support roller 312 inside, and the heating block 320 is freely rotatably supported.

[0166] The heating block 320 is a resistance heating element as an example of a heating source, and supplies heat to the conveyor belt 310.

[0167] Note that in the article conveying device 300, the heating block 320 is a heating source, but the heating source is not limited to this, and can be a non-contact heating source such as an infrared heater.

[0168] A lubricant application member, not shown, is provided on the inner peripheral surface of the conveyor belt 310. The lubricant application member is configured, for example, in contact with the inner peripheral surface of the conveyor belt 310, and supplies an appropriate amount of lubricant to the inner peripheral surface of the conveyor belt 310.

[0169] Specific examples and preferred examples of the lubricant are the same as those described above for the lubricant used in the heat sealing device.

[0170] Note that in the article conveying device 300, the lubricant is supplied to the inner peripheral surface of the conveyor belt 310 by the lubricant application member, but it can also be in a form that does not use a lubricant application member and lubricant.

[0171] In the article conveying device 300, the conveyor belt 310 is first rotated in the direction of arrow E by the rotation of the drive roller 311, thereby moving the article 350 as a heated body in the direction of arrow F on the conveyor belt 310, and introducing it into the heating region.

[0172] The article 350 conveyed to the heating region is conveyed by the rotation of the conveyor belt 310, and heated by the heating block 320, so that the article 350 is heated.

[0173] After that, the heated article 350 is further conveyed by the rotation of the conveyor belt 310, and discharged from the heating region.

[0174] [Example]

[0175] Examples of the present application will be described below, but the present application is not limited to the following examples. Note that in the following description, "parts" and "%" are on a mass basis, unless otherwise specified.

[0176] [Manufacture of endless belt]

[0177] [Manufacture of endless belt 1]

[0178] (Production of the base layer 1)

[0179] A commercially available polyimide precursor solution (Uvarnish S, manufactured by Ube Industries, Ltd.) was applied to the surface of a cylindrical stainless steel mold having an outer diameter of 118 mm by the dip coating method, whereby a coating film was formed. Next, the solvent in the coating film was volatilized by drying the coating film at 100°C for 30 minutes, and then imidization was performed by baking at 380°C for 30 minutes, thereby forming a polyimide coating film having a film thickness of 60 μm. The polyimide coating film was peeled off from the surface of the stainless steel mold, whereby a heat-resistant polyimide base having a circular band shape with an inner diameter of 118 mm, a film thickness of 60 μm, and a length of 370 mm was obtained, and used as the base layer 1.

[0180] (Formation of the back layer and the surface layer)

[0181] A dispersion liquid containing PTFE (PTFE dispersion, manufactured by Daikin Industries, Ltd., product name: POLYFLON PTFE-D series) was used to form an un-baked and un-crosslinked PTFE layer on the inner peripheral surface of the base layer 1 by the centrifugal molding method (mold temperature: 200°C, rotation speed: 200 rpm, rotation time: 20 minutes). Thereafter, baking was performed by keeping in a heating furnace at 340°C for 20 minutes, whereby an un-crosslinked PTFE layer was obtained.

[0182] Next, a dispersion liquid containing PFA (PFA dispersion) was used to coat only the outer peripheral surface of the base layer 1 by the dip coating method. Note that the dispersion liquid adhered to the inner peripheral surface of the base layer 1 (i.e., on the un-crosslinked PTFE layer) was removed by wiping. Thereafter, baking was performed by keeping in a heating furnace at 380°C for 30 minutes, whereby an un-crosslinked PFA layer was obtained.

[0183] Next, the un-crosslinked PTFE layer and the un-crosslinked PFA layer were crosslinked by irradiating a radioactive ray (kind of radioactive ray: electron ray, irradiation conditions: 50 kGy) from the outer peripheral surface side of the base layer 1 in an atmosphere having an oxygen concentration of 1000 ppm or less while the temperature was adjusted to 280°C.

[0184] As described above, a circular band 1 was obtained in which a back layer 1 having a film thickness of 15 μm as a crosslinked PTFE layer was arranged on the inner peripheral surface of the base layer 1 and a surface layer 1 having a film thickness of 30 μm as a crosslinked PFA layer was arranged on the outer peripheral surface of the base layer 1.

[0185] (Production of the circular band 2)

[0186] (Formation of the back layer and the surface layer)

[0187] A dispersion liquid containing PTFE (PTFE dispersion, manufactured by Daikin Industries, Ltd., product name: POLYFLON PTFE-D series) was used to form an un-baked and un-crosslinked PTFE layer on the inner circumferential surface of the base layer 1 by a centrifugal molding method (mold temperature: 200°C, rotation speed: 200 rpm, rotation time: 20 minutes). Thereafter, baking was performed by keeping in a heating furnace at 340°C for 20 minutes, to obtain an un-crosslinked PTFE layer.

[0188] Next, a dispersion liquid containing PTFE (PTFE dispersion, manufactured by Daikin Industries, Ltd., product name: POLYFLON PTFE-D series) was used to coat only the outer circumferential surface of the base layer 1 by a dip coating method. Note that the dispersion liquid adhered to the inner circumferential surface of the base layer 1 (i.e., on the un-crosslinked PTFE layer) was removed by wiping. Thereafter, baking was performed by keeping in a heating furnace at 340°C for 20 minutes, to obtain an un-crosslinked PTFE layer.

[0189] Next, for the un-crosslinked PTFE layer formed on the inner circumferential surface of the base layer 1 and the un-crosslinked PTFE layer formed on the outer circumferential surface of the base layer 1, crosslinking was performed by irradiating a radiation (kind of radiation: electron beam, irradiation conditions: 50 kGy) from the outer circumferential surface side of the base layer 1 in an atmosphere with an oxygen concentration of 1000 ppm or less while adjusting the temperature to 300°C.

[0190] As described above, by setting the electron beam irradiation conditions to 50 kGy, crosslinking occurs more on the outer circumferential surface than on the inner circumferential surface, and HMi(130°C) < HMo(130°C). In addition, HMo(25°C) < HMi(25°C).

[0191] As implemented as above, a ring-shaped belt 2 was obtained in which the back layer 2 as a crosslinked PTFE layer with a film thickness of 15 μm was arranged on the inner circumferential surface of the base layer 1 and the surface layer 2 as a crosslinked PTFE layer with a film thickness of 30 μm and a different Martens hardness from the inner circumferential surface was arranged on the outer circumferential surface of the base layer 1.

[0192] <Manufacture of Ring-Shaped Belt 3>

[0193] (Manufacture of Base Layer 3)

[0194] As the crosslinked PTFE particles, crosslinked PTFE particles obtained as follows were used. Specifically, after PTFE particles (manufactured by Daikin Industries, Ltd., No. NEW POLYFLON PTFE M112) were fixed in a mat shape, they were heated to 300°C in an atmosphere gas having low oxygen and crosslinked by irradiating them with a radiation (kind of radiation: electron beam, irradiation conditions: 200 kGy) in this state, after which they were cooled to 25°C, and then processed with a pulverizer to obtain crosslinked PTFE particles having a number average particle diameter of 100 nm.

[0195] To 100 parts by mass of a commercially available polyimide precursor solution (Uvarnish S, manufactured by Ube Industries, Ltd.) was added 10 parts by mass of the above crosslinked PTFE particles having a number average particle diameter of 100 nm, and the mixture was stirred for 60 minutes using a bead mill to obtain a crosslinked PTFE particle dispersion liquid.

[0196] The above crosslinked PTFE particle dispersion liquid was applied to the surface of a cylindrical stainless steel mold having an outer diameter of 118 mm by the dip coating method to form a coating film. Next, the solvent in the coating film was volatilized by drying the coating film at 100°C for 30 minutes, and then imidization was performed by baking the coating film at 380°C for 30 minutes to form a polyimide coating film having a thickness of 60 μm and containing crosslinked PTFE particles. By peeling the polyimide coating film from the surface of the stainless steel mold, a heat-resistant polyimide base material in the form of an annular band having an inner diameter of 118 mm, a thickness of 60 μm, and a length of 370 mm was obtained, and this was used as the base layer 3 (crosslinked fluororesin particle content: 15% by mass).

[0197] (Formation of surface layer)

[0198] A dispersion liquid containing PFA (PFA dispersion) was applied to the outer peripheral surface of the base layer 3 by the dip coating method. Note that the dispersion liquid adhering to the inner peripheral surface of the base layer 3 was removed by wiping. Subsequently, baking was performed by keeping the dispersion liquid in a heating furnace at 380°C for 30 minutes to obtain an uncrosslinked PFA layer.

[0199] Next, the uncrosslinked PFA layer was crosslinked by irradiating it with a radiation (kind of radiation: electron beam, irradiation conditions: 200 kGy) from the outer peripheral surface side of the base layer 3 in an atmosphere having an oxygen concentration of 1000 ppm or less while the temperature was adjusted to 280°C.

[0200] As described above, an annular band 3 was obtained in which a surface layer 3 having a thickness of 30 μm and serving as a crosslinked PFA layer was disposed on the outer peripheral surface of the base layer 3 containing crosslinked PTFE particles.

[0201] <Manufacture of annular band 4>

[0202] (Formation of surface layer)

[0203] A dispersion liquid containing PTFE (PTFE dispersion, manufactured by Daikin Industries, Ltd., product name: POLYFLON PTFE-D series) was used, and only the outer peripheral surface of the base material layer 3 was coated by the dip coating method. Note that the dispersion liquid adhered to the inner peripheral surface of the base material layer 3 was removed by wiping. Subsequently, firing was performed by keeping in a heating furnace at 340°C for 20 minutes, and an uncrosslinked PTFE layer was obtained.

[0204] Next, for the uncrosslinked PTFE layer, in a state where the temperature was adjusted to 300°C, irradiation of a radiation (kind of radiation: electron beam, irradiation conditions: 200 kGy) was performed from the outer peripheral surface side of the base material layer 3 in an atmosphere with an oxygen concentration of 1000 ppm or less, and crosslinking was performed.

[0205] As described above, the annular tape 4 in which the surface layer 4 having a film thickness of 30 μm as a crosslinked PTFE layer was arranged on the outer peripheral surface of the base material layer 3 containing the crosslinked PTFE particles was obtained.

[0206] <Manufacture of annular tape C1>

[0207] (Formation of surface layer)

[0208] A dispersion liquid containing PFA (PFA dispersion) was used, and only the outer peripheral surface of the base material layer 1 was coated by the dip coating method. Note that the dispersion liquid adhered to the inner peripheral surface of the base material layer 1 was removed by wiping. Subsequently, firing was performed by keeping in a heating furnace at 380°C for 30 minutes, and an uncrosslinked non-crosslinked PFA layer was obtained.

[0209] As described above, the annular tape C1 in which the surface layer C1 having a film thickness of 30 μm as an uncrosslinked non-crosslinked PFA layer was arranged on the outer peripheral surface of the base material layer 1 was obtained.

[0210] <Manufacture of annular tape C2>

[0211] (Formation of back surface layer and surface layer)

[0212] A dispersion liquid containing PTFE (PTFE dispersion, manufactured by Daikin Industries, Ltd., product name: POLYFLON PTFE-D series) was used, and an uncrosslinked PTFE layer that was not fired was formed on the inner peripheral surface of the base material layer 1 by the centrifugal molding method (mold temperature: 200°C, rotation speed: 200 rpm, rotation time: 20 minutes). Subsequently, firing was performed by keeping in a heating furnace at 340°C for 20 minutes, and an uncrosslinked non-crosslinked PTFE layer was obtained.

[0213] Next, using a dispersion liquid containing PFA (PFA dispersion), only the outer peripheral surface of the base material layer 1 was coated by the dip coating method. Note that the dispersion liquid adhered to the inner peripheral surface of the base material layer 1 (i.e., on the non-crosslinked PTFE layer) was removed by wiping. Subsequently, baking was performed by keeping in a heating furnace at 380°C for 30 minutes, to obtain a non-crosslinked PFA layer.

[0214] As implemented as above, the endless belt C2 in which the film-thickness 15 μm back surface layer C2 as the non-crosslinked PTFE layer was arranged on the inner peripheral surface of the base material layer 1 and the film-thickness 30 μm surface layer C2 as the non-crosslinked PFA layer was arranged on the outer peripheral surface of the base material layer 1 was obtained.

[0215] <Manufacture of the endless belt C3>

[0216] (Formation of the surface layer)

[0217] Using a dispersion liquid containing PFA (PFA dispersion), only the outer peripheral surface of the base material layer 3 was coated by the dip coating method. Note that the dispersion liquid adhered to the inner peripheral surface of the base material layer 3 was removed by wiping. Subsequently, baking was performed by keeping in a heating furnace at 380°C for 30 minutes, to obtain a non-crosslinked PFA layer.

[0218] As implemented as above, the endless belt C3 in which the film-thickness 30 μm surface layer C3 as the non-crosslinked PFA layer was arranged on the outer peripheral surface of the base material layer 3 containing the crosslinked PTFE particles was obtained.

[0219] <Manufacture of the endless belt C4>

[0220] (Formation of the surface layer)

[0221] Using a dispersion liquid containing PFA (PFA dispersion), only the outer peripheral surface of the base material layer 1 was coated by the dip coating method. Note that the dispersion liquid adhered to the inner peripheral surface of the base material layer 1 was removed by wiping. Subsequently, baking was performed by keeping in a heating furnace at 380°C for 30 minutes, to obtain a non-crosslinked PFA layer.

[0222] Next, for the non-crosslinked PFA layer, in a state where the temperature was adjusted to 280°C, irradiation of a radioactive ray (kind of the radioactive ray: electron ray, irradiation condition: 200 kGy) was performed from the outer peripheral surface side of the base material layer 1 in an atmosphere having an oxygen concentration of 1000 ppm or less.

[0223] As implemented as above, the endless belt C4 in which the film-thickness 30 μm surface layer C4 as the crosslinked PFA layer was arranged on the outer peripheral surface of the base material layer 1 was obtained.

[0224] [Measurement of Martens Hardness of the Ring-Shaped Belt]

[0225] For the obtained ring-shaped belt, the Martens hardness of the outer peripheral surface of the belt at 130°C "HMo(130°C)", the Martens hardness of the inner peripheral surface of the belt at 130°C "HMi(130°C)", the Martens hardness of the outer peripheral surface of the belt at 25°C "HMo(25°C)", and the Martens hardness of the inner peripheral surface of the belt at 25°C "HMi(25°C)" were measured by the above-described method. The results are shown in Table 1 and Table 2. Note that the units of HMo(130°C), HMi(130°C), HMo(25°C), and HMi(25°C) in Table 1 and Table 2 are "N / mm 2 ".

[0226] [Evaluation of the Ring-Shaped Belt]

[0227] The obtained ring-shaped belt was used as the sealing belt 430 of the heat-sealing device shown in FIG. 1. Figure 3

[0228] Note that a lubricant was used on the inner peripheral surface of the sealing belt 430. As the lubricant, "perfluoropolyether oil" was used in the examples and comparative examples other than Example 5, and "silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., product name: KF968-100CS)" was used in Example 5.

[0229] On the other hand, the heated body was a laminate in which the sealing portion was in contact and overlapped, and as the heated body, a laminate in which a paper sheet having a thickness of 100 μm and a size of 10 cm x 10 cm was interposed between laminated films (manufactured by Gohyo Paper Co., Ltd., overall thickness: 105 μm) was used, and the adhesion of the sealing portion in the laminate was continuously performed 500,000 times (temperature: 150°C, pressure: 0.2 MPa, conveyance speed: 200 mm / s).

[0230] [Evaluation of Change in Torque over Time]

[0231] The torque applied to the driving roller 431 was measured, and the change in torque over time (i.e., the increase in rotational load) was evaluated. Note that the smaller the increase in torque, the higher the wear resistance of the inner peripheral surface of the belt. The cause of the change in torque over time is not certain, but it is presumed to be caused by the wear powder generated by the wear of the inner peripheral surface of the sealing belt 430. The evaluation criteria are as follows, and the results are shown in Table 1 and Table 2. In the related description of the following criteria, Ti is the initial torque, and Te is the torque after the adhesion of the sealing portion was performed 500,000 times.

[0232] G1: Te < 1.2 Ti

[0233] G2: 1.2 Ti ≦ Te < 1.5 Ti

[0234] ​G3: 1.5Ti ≦ Te < 1.7Ti

[0235] G4: 1.7Ti ≦ Te < 2Ti

[0236] G5: 2Ti ≦ Te

[0237] < Evaluation of surface roughness of heated body >

[0238] The surface roughness of the surface of the laminated body after 500,000 times of bonding was measured using a surface roughness measuring device (Tokyo Seimitsu Manufacturing, Model: SURFCOM NEX100), and the surface roughness of the heated body was evaluated. Note that the smaller the surface roughness of the heated body, the higher the wear resistance of the outer peripheral surface. The cause of the surface roughness of the heated body is not certain, but it is presumed that it is caused by the roughening of the outer peripheral surface due to the wear of the outer peripheral surface of the sealing tape 430, and the uneven heating of the heated body. The evaluation criteria are as follows, and the results are shown in Tables 1 and 2. In the following description of the criteria, Ri is the surface roughness of the first heated body, and Re is the surface roughness of the 500,000th heated body.

[0239] G1: Re < 1.2Ri

[0240] G2: 1.2Ri ≦ Re < 1.5Ri

[0241] G3: 1.5Ri ≦ Re < 1.7Ri

[0242] G4: 1.7Ri ≦ Re < 2Ri

[0243] G5: 2Ri ≦ Re

[0244] < Evaluation of bonding failure of heated body >

[0245] The bonding strength of the sealing portion of the laminated body after 500,000 times of bonding was measured using a digital force gauge (Imada Co., Ltd., Model: ZTS series), and the bonding failure was evaluated. Note that the less the bonding failure, or the absence of bonding failure, means that the higher the following property of the sealing tape 430: the ability to follow the unevenness. The cause of the bonding failure is not certain, but it is presumed that it is caused by the uneven heating due to the difficulty of the outer peripheral surface of the sealing tape 430 to follow the unevenness of the heated body. The evaluation criteria are as follows, and the results are shown in Tables 1 and 2. In the following description of the criteria, Sb is the bonding strength of the 500,000th laminated portion (i.e., the sealing portion of the laminated body) in the examples (i.e., Example 2 and Example 4) that have the highest bonding strength among the examples in this case, and Se is the bonding strength of the 500,000th laminated portion in the corresponding examples.

[0246] G1: 0.8Sb < Se ≦ Sb

[0247] G2: 0.6 < Sb < Se ≦ 0.8 Sb

[0248] G3: 0.4 < Sb < Se ≦ 0.6 Sb

[0249] G4: 0.2 < Sb < Se ≦ 0.4 Sb

[0250] G5: Se ≦ 0.2 Sb

[0251] [Table 1]

[0252]

[0253] [Table 2]

[0254]

[0255] According to the results shown in Tables 1 and 2 described above, the endless belt of the present embodiment achieved suppression of the torque increase over time, suppression of the surface roughness of the heated body, and suppression of the poor adhesion of the heated body, and gave consideration to the wear resistance and the concave-convex followability of the outer peripheral surface and the inner peripheral surface of the belt.

Claims

1. An endless belt, comprising: a base material layer, and a surface layer provided on an outer peripheral surface of the base material layer, formed of a crosslinked fluororesin layer, an inner peripheral surface of the belt is composed of a layer containing a crosslinked fluororesin, a Martens hardness at 130°C of the inner peripheral surface of the belt is higher than a Martens hardness at 130°C of the outer peripheral surface of the belt, 2. An endless belt, comprising: a base material layer, and a surface layer provided on an outer peripheral surface of the base material layer, formed of a crosslinked fluororesin layer, an inner peripheral surface of the belt is composed of a layer containing a crosslinked fluororesin, The difference between the Martens hardness at 130°C of the outer periphery of the band and the Martens hardness at 130°C of the inner periphery of the band is 2 N / mm 2 The above 10 N / mm 2 The following. a Martens hardness at 130°C of the inner peripheral surface of the belt is higher than a Martens hardness at 130°C of the outer peripheral surface of the belt, the layer containing a crosslinked fluororesin is a crosslinked fluororesin layer provided on an inner peripheral surface of the base material layer. the layer containing a crosslinked fluororesin is the base material layer containing crosslinked fluororesin particles.

6. An endless belt, comprising: a base material layer, and a surface layer provided on an outer peripheral surface of the base material layer, formed of a crosslinked fluororesin layer, an inner peripheral surface of the belt is composed of a layer containing a crosslinked fluororesin, The above band has a martens hardness of 2 N / mm at 130°C on the peripheral surface 2 Above 10 N / mm 2 Hereinafter, the above band has a martens hardness of 4 N / mm at 130°C on the peripheral surface 2 Above 12 N / mm 2 Hereinafter.

3. The endless belt of claim 2, wherein, The difference between the Martens hardness at 130°C of the outer periphery of the strip and the Martens hardness at 130°C of the inner periphery of the strip is 2 N / mm 2 The above 10 N / mm 2 The following.

4. The endless belt according to any one of claims 1 to 3, wherein a Martens hardness at 130°C of the inner peripheral surface of the belt is higher than a Martens hardness at 130°C of the outer peripheral surface of the belt, 5. The endless belt according to any one of claims 1 to 3, wherein a Martens hardness at 25°C of the inner peripheral surface of the belt is lower than a Martens hardness at 25°C of the outer peripheral surface of the belt. the crosslinked fluororesin contained in the surface layer is a perfluoroalkyl vinyl ether-tetrafluoroethylene copolymer resin, the crosslinked fluororesin contained in the layer constituting the inner peripheral surface of the belt is a polytetrafluoroethylene resin.

10. A heat-sealing device, comprising: a first rotating body, a second rotating body disposed in contact with an outer surface of the first rotating body, the second rotating body being formed of the endless belt according to any one of claims 1 to 9, and a pressing member disposed inside the second rotating body to press the second rotating body toward the first rotating body from an inner surface of the second rotating body.

11. A fixing device, comprising: a first rotating body, a second rotating body disposed in contact with an outer surface of the first rotating body, the second rotating body being formed of the endless belt according to any one of claims 1 to 9, and a pressing member disposed inside the second rotating body to press the second rotating body toward the first rotating body from an inner surface of the second rotating body.

7. The endless belt of claim 6, wherein, The above-mentioned band has a martens hardness of 15 N / mm at 25°C 2 Above 23 N / mm 2 Hereinafter, the above-mentioned band has a martens hardness of 13 N / mm at 25°C 2 Above 19 N / mm 2 Hereinafter.

8. The endless belt of claim 6 or claim 7, wherein, The difference between the Martens hardness at 25°C of the band inner periphery and the Martens hardness at 25°C of the band outer periphery is 2 N / mm 2 The above 10 N / mm 2 The following.

9. The endless belt according to any one of claims 1 to 3, 6 and 7, wherein, 12. An article conveying device, comprising: an article conveying belt formed of the endless belt according to any one of claims 1 to 9, and a heating source to heat a heated body conveyed by the article conveying belt. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​

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