Fixing member, fixing device, and image forming device

Abstract

To provide a fixing member comprising an elastic layer formed of a rubber molding with high thermal conductivity and low hardness.SOLUTION: A fixing member is provided, comprising an elastic layer formed of a rubber molding including a rubber foam and granular hollow aggregates of a carbon material contained in foam cells of the rubber foam.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] Among rubber moldings, for example, there is a demand for rubber moldings that are soft and have high thermal conductivity. For example, in an image forming apparatus (such as a copier, facsimile, or printer) using an electrophotographic method, an elastic layer of a fixing member used when fixing a toner image formed on a recording medium onto the recording medium can be mentioned.

[0003] Carbon nanotubes, which are carbon materials, are also one example of thermally conductive materials. For example, Patent Document 1 discloses a functional film using carbon nanotubes, which is made of entangled carbon nanotubes and contains aggregates with a diameter of 50 μm or less, a height of less than 5 μm, and a ratio of the height to the diameter (height / diameter) of less than 0.1. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2019-140105 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present disclosure is to provide a fixing member having an elastic layer made of a rubber molded body that has high thermal conductivity and low hardness compared to a rubber foam containing a carbon material inside. [Means for solving the problem]

[0006] Specific means for solving the above problems include the following aspects. <1> A rubber molded article comprising: a rubber foam; and granular hollow aggregates of a carbon material contained in foam cells of the rubber foam.

[0007] <2> a diameter X of the foam cells is larger than a maximum diameter Y of the granular hollow aggregates of the carbon material, and the foaming rate distribution of the rubber foam has a variation of 20% or less; <1> The rubber molded article according to claim 1. <3> The foam cell diameter X is more than 1.0 times and not more than 50 times the maximum diameter Y of the granular hollow aggregate of the carbon material. <2> The rubber molded article according to claim 1. <4> The open cell ratio of the rubber foam is less than 100%. <1> ~ <3> 1. The rubber molded article according to any one of the above. <5> The open cell ratio of the rubber foam is 50% or less. <4> The rubber molded article according to claim 1. <6> the occupancy rate of the granular hollow aggregates of the carbon material in the foam cells is more than 0% and less than 100%; <1> ~ <5> 1. The rubber molded article according to any one of the above. <7> the occupancy rate of the granular hollow aggregates of the carbon material in the foam cells is 5% or more and 50% or less; <6> The rubber molded article according to claim 1. <8> The granular hollow aggregate of the carbon material is a granular hollow aggregate formed by a plurality of fibrous carbons entangled with each other. <1> ~ <7> 1. The rubber molded article according to any one of the above. <9> A rubber foam and a carbon material contained in foam cells of the rubber foam, A rubber molded product having a thermal conductivity of 1.0 W / m·K or more and 100 W / m·K or less, and an Asker C hardness of 10 or more and 60 or less.

[0008] <10> <1> ~ <9> 10. A fixing member having an elastic layer formed from the rubber molded article according to any one of claims 1 to 9. <11> a first rotating body and a second rotating body arranged in contact with an outer surface of the first rotating body, At least one of the first rotating body and the second rotating body <10> The fixing member according to claim 1, a fixing device that fixes a toner image formed on a surface of the recording medium by inserting the recording medium through a contact portion between the first rotating body and the second rotating body; <12> 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 charged surface of the 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 onto a surface of a recording medium; fixing the toner image to the recording medium; <11> a fixing means configured by the fixing device described in An image forming apparatus comprising: [Effects of the Invention]

[0009] <1> , <6> , <8> , or <9> According to the present invention, a rubber molded article is provided that has high thermal conductivity and low hardness compared to a rubber foam containing a carbon material inside. <2> According to the invention, a rubber molded article is provided in which the diameter X of the foam cells is larger than the maximum diameter Y of the granular hollow aggregates of the carbon material, and the rubber foam has a high thermal conductivity and low hardness compared to a rubber foam having a foaming rate distribution variation of more than 20%. <3> According to the invention, a rubber molded article is provided which has high thermal conductivity and low hardness compared to when the foam cell diameter X is 1.0 times or less or more than 50 times the maximum diameter Y of the granular hollow aggregate of the carbon material. <4> According to the invention, a rubber molded article is provided which has high thermal conductivity and low hardness compared to a rubber foam having an open cell ratio of 100%. <5> According to the invention, a rubber molded article is provided which has high thermal conductivity and low hardness compared to rubber foams having an open cell ratio of more than 50%. <7> According to the present invention, a rubber molded article is provided which has high thermal conductivity and low hardness compared to when the occupancy rate of the granular hollow aggregates of carbon material in the foam cells is less than 5% or more than 50%.

[0010] <10> According to the present invention, a fixing member is provided that has an elastic layer that has high thermal conductivity and low hardness compared to a fixing member that has an elastic layer made of a rubber molded body containing a carbon material inside a rubber foam. <11> or <12> According to the invention, a fixing device or an image forming device is provided that includes a fixing member having an elastic layer that has high thermal conductivity and low hardness compared to a fixing member that has an elastic layer made of a rubber molded body containing a carbon material inside a rubber foam. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 2 is a schematic cross-sectional view illustrating an example of a fixing belt that is a fixing member 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. 4 is a schematic configuration diagram illustrating an example of a fixing device according to a second embodiment of the present disclosure. [Figure 4] FIG. 10 is a schematic configuration diagram illustrating an example of a fixing device according to a third embodiment of the present disclosure. [Figure 5] 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0012] 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.

[0013] 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.

[0014] 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.

[0015] In this specification, unless otherwise specified, when the term "rubber molded article of the present disclosure" is used, it refers to both the first and second embodiments described below.

[0016] <First embodiment of rubber molded body> A first embodiment of a rubber molded body of the present disclosure is a rubber molded body including a rubber foam and granular hollow aggregates of a carbon material contained in foam cells of the rubber foam.

[0017] Here, in this specification, the "granular hollow aggregate of a carbon material" refers to a granular aggregate formed by combining carbon materials, and the granular hollow aggregate contains carbon material and voids between the carbon materials (i.e., voids forming a hollow state). Examples of the carbon material include carbon fiber, graphene, and fullerene. If the carbon material is carbon fiber, the granular hollow aggregate of the carbon material is preferably a granular hollow aggregate formed by a plurality of fibrous carbons intertwined with each other. If the carbon fiber is graphene, sp 2 The granular hollow aggregate is preferably formed by combining a plurality of sheet-like structures (ie, graphenes) each consisting of a single layer of carbon atoms bonded together in a plane.

[0018] The first embodiment of the rubber molded article of the present disclosure has high thermal conductivity and low hardness due to the above-described configuration, and the reason for this is presumed to be as follows. Rubber foams are used to achieve low hardness in rubber moldings, but when thermally conductive materials (such as carbon nanotubes) are incorporated into the rubber foam, the thermal conductivity improves, but the hardness also increases, which is a problem. In the first embodiment of the rubber molded article of the present disclosure, granular hollow aggregates of a carbon material are contained within the foam cells of the rubber foam, rather than within the interior of the rubber foam. This configuration can improve thermal conductivity without including a thermally conductive material within the rubber foam. Therefore, it is expected that a rubber molded article can be obtained that exhibits high thermal conductivity while achieving low hardness due to the use of a rubber foam.

[0019] [Preferred aspect of the first embodiment of the rubber molded article] In the first embodiment of the rubber molded body of the present disclosure, from the viewpoint of achieving both high thermal conductivity and low hardness, it is preferable that the diameter X of the foam cells is larger than the maximum diameter Y of the granular hollow aggregates of the carbon material, and that the foaming rate distribution of the rubber foam has a variation of 20% or less. In particular, from the viewpoint of achieving both high thermal conductivity and low hardness, the foam cell diameter X is more preferably more than 1.0 times and not more than 50 times the maximum diameter Y of the granular hollow aggregate of the carbon material, and even more preferably 10 times or more and not more than 30 times. The smaller the variation in foaming rate distribution of the rubber foam, the better, and it is more preferably 15% or less, further preferably 10% or less, particularly preferably 5% or less, and most preferably 0%.

[0020] In the first embodiment of the rubber molded body of the present disclosure, from the viewpoint of achieving both high thermal conductivity and low hardness, the open cell ratio of the rubber foam is preferably less than 100%, more preferably 50% or less, and even more preferably 10% or less. Here, the open cell ratio refers to the ratio of open cells to the foam cells (i.e., cells) of a rubber foam. Here, open cells refer to cells (also called open cells) that are partially exposed on the surface of the rubber foam (molded rubber product) and communicate with the outside of the rubber foam. Foam cells include not only open cells but also closed cells, and closed cells refer to cells that are entirely surrounded by walls (i.e., the solid phase of the rubber foam).

[0021] In the first embodiment of the rubber molded body of the present disclosure, from the viewpoint of achieving both high thermal conductivity and low hardness, the occupancy rate of the granular hollow aggregates of carbon material in the foam cells is preferably more than 0% and less than 100%, and more preferably 5% or more and 50% or less. Here, the occupancy rate of the carbonaceous material particulate hollow aggregates in the foam cells means the proportion of the carbonaceous material particulate hollow aggregates contained in the foam cells relative to the size of the foam cells (i.e., air bubbles). Note that an occupancy rate of less than 100% means that gas (e.g., air) is present in the foam cells in addition to the carbonaceous material particulate hollow aggregates.

[0022] Here, the foam cell diameter X, the maximum diameter Y of the granular hollow aggregates of the carbon material, the variation in foaming rate distribution of the rubber foam, the open cell ratio, and the occupancy rate of the granular hollow aggregates of the carbon material in the foam cells can be determined by the following method. The rubber molded article is cut in a desired direction using a microtome to obtain a cross section for measurement. If the rubber molded article is a layered article, the cross section for measurement is preferably a cross section obtained by cutting the layered article in the thickness direction. The obtained cross section for measurement is observed using an electron microscope (e.g., SU-70 manufactured by Hitachi High-Technologies Corporation) to obtain a cross-sectional image. The obtained cross-sectional image is analyzed using image analysis software (e.g., Image Factory manufactured by Imsoft), and the obtained data are used to determine the foam cell diameter X, the maximum diameter Y of the granular hollow aggregates of the carbon material, the open cell ratio, and the occupancy rate of the granular hollow aggregates of the carbon material in the foam cells. Specifically, the foam cell diameter X is the arithmetic mean value of the maximum diameters of the foam cells (i.e., bubbles) in the analyzed cross-sectional image. If there are many connected bubbles, the connected bubbles can be artificially separated based on their shape, etc., to form independent bubbles, and the maximum diameter of these independent bubbles can be determined. That is, if a connected bubble has a shape in which two bubbles are connected, it is artificially separated into two, and the maximum diameter of each of the two independent bubbles is determined. To determine the variation in foaming rate distribution of a rubber foam, first divide the cross-sectional image into 10 equal parts and determine the foaming rate in each of the divided areas. The variation in the foaming rate distribution is determined by calculating the difference between the maximum and minimum values of the determined foaming rate. The foaming rate can be calculated by dividing the total area of the bubbles by the total area of one area x 100. The maximum diameter Y of the granular hollow aggregates of the carbon material is defined as the arithmetic mean value of the maximum diameters of the granular hollow aggregates of the carbon material contained in the foam cells in the analyzed cross-sectional image. The open cell ratio is calculated by dividing the total area of open cells in the analyzed cross-sectional image by the total area of foam cells (ie, bubbles) in the analyzed cross-sectional image × 100. The occupancy rate of the carbon material granular hollow aggregates in the foam cells is determined by extracting foam cells containing the carbon material granular hollow aggregates from the analyzed cross-sectional image, calculating the occupancy rate for each foam cell by the formula: area of the carbon material granular hollow aggregates / area of foam cells × 100, and then taking the arithmetic mean value of these values.

[0023] The rubber foam and the hollow granular aggregate of carbon material used in the first embodiment of the rubber molded article of the present disclosure will be described below.

[0024] [Rubber foam] A rubber foam is a structure made of a rubber material that has at least an internal cavity (that is, foam cells). Examples of rubber materials include silicone rubber, fluororubber, fluorosilicone rubber, etc. Among them, silicone rubber and fluororubber are selected from the viewpoints of heat resistance, thermal conductivity, etc., and silicone rubber is preferably selected.

[0025] 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).

[0026] 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.

[0027] Examples of fluororubbers include vinylidene fluoride rubber, tetrafluoroethylene / propylene rubber, tetrafluoroethylene / perfluoromethylvinyl ether rubber, phosphazene rubber, and fluoropolyether.

[0028] The rubber material used for the rubber foam preferably contains silicone rubber as a main component (that is, the rubber material contains silicone rubber in an amount of 50% by mass or more relative to the total mass of the rubber 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 rubber material contained in the rubber foam.

[0029] In addition to the rubber materials described above, the rubber foam may contain additives such as inorganic fillers, softeners (paraffin-based, etc.), processing aids (stearic acid, etc.), antioxidants (amine-based, etc.), and vulcanizing agents (sulfur, metal oxides, peroxides, etc.). Inorganic fillers also include carbon materials such as carbon black and carbon nanotubes, but when the rubber foam contains a carbon material, it is preferably used within a range that does not impair the effects of the rubber molded body of the present disclosure.

[0030] The shape and size of the rubber foam are not particularly limited and may be determined appropriately depending on the intended use.

[0031] The diameter of the foam cells of the rubber foam may be determined appropriately depending on the use of the rubber molded article, the physical properties required for that use, and the like. The foam cell diameter of the rubber foam is, for example, preferably 50 μm or more and 300 μm or less, and more preferably 100 μm or more and 200 μm or less.

[0032] The foaming ratio of the rubber foam may be determined appropriately depending on the use of the rubber molded article, the physical properties required for that use, and the like.

[0033] [Hollow granular aggregates of carbon materials] A first embodiment of the rubber molded article of the present disclosure includes granular hollow aggregates of a carbon material enclosed in foam cells of a rubber foam. The granular hollow aggregates of carbon material act as a thermally conductive material.

[0034] From the viewpoint of being enclosed in the foam cells, the maximum diameter of the granular hollow aggregates of the carbon material is preferably smaller than the diameter of the foam cells (the above-mentioned foam cell diameter X). For example, the maximum diameter of the granular hollow aggregates of the carbon material is preferably 1 μm or more and 300 μm or less, and more preferably 5 μm or more and 50 μm or less.

[0035] The shape of the granular hollow aggregates of a carbon material is not particularly limited as long as they can be contained in the foam cells. The granular hollow aggregates of a carbon material may be, for example, spherical, ellipsoidal, or irregular.

[0036] From the viewpoints of mechanical strength, elasticity, and manufacturing, the ratio of the minor axis B to the major axis A of the fiber aggregate (minor axis B / major axis A) of the granular hollow aggregate of carbon material is preferably 0.1 or more and 1 or less, more preferably 0.5 or more and 1 or less, and even more preferably 0.8 or more and 1 or less.

[0037] The major axis A and minor axis B are measured using the following method. In the same manner as when measuring the diameter X of the foam cells of the rubber molding, the cross section to be measured is observed under an electron microscope, and the longest axis A of the granular hollow aggregate of carbon material in the foam cells and the longest axis B in the direction perpendicular to the long axis A are measured. The number of measurement samples of the granular hollow aggregate of carbon material is 10, and the "longest axis A" and "short axis B" are each the arithmetic mean values of the 10 samples.

[0038] As the granular hollow aggregate of carbon material, a granular hollow aggregate formed by a plurality of fibrous carbons intertwined with each other, or a granular hollow aggregate formed by a combination of a plurality of graphenes, is preferred, and from the viewpoints of ease of availability and the fact that high thermal conductivity performance can be obtained, a granular hollow aggregate formed by a plurality of fibrous carbons intertwined with each other (hereinafter also referred to as a fibrous aggregate) is more preferred.

[0039] The length of the fibrous carbon contained in the fiber aggregate is preferably 1 μm or more and 100 μm or less, more preferably 2 μm or more and 80 μm or less, and even more preferably 3 μm or more and 60 μm or less.

[0040] The diameter of the fibrous carbon contained in the fiber aggregate is preferably 20 nm or more and 300 nm or less, more preferably 25 nm or more and 250 nm or less, and even more preferably 30 nm or more and 200 nm or less.

[0041] The length and diameter of the fibrous carbon constituting the fiber aggregate are measured by the following method. In the same manner as when measuring the diameter X of the foam cells of the rubber molding, the cross section for measurement is observed under an electron microscope, and the length and diameter of the fibrous carbon constituting the fiber aggregate are measured. The number of measurement samples of the fiber aggregate is 10, and measurements are made on two pieces of fibrous carbon per fiber polymer, and the "length of the fibrous carbon constituting the fiber aggregate" and the "diameter of the fibrous carbon constituting the fiber aggregate" are each the arithmetic mean value of the measurement values for 20 points (10 samples x 2 pieces).

[0042] The number of fibrous carbon fibers contained in the fiber assembly is not particularly limited as long as it is plural (ie, two or more).

[0043] The fibrous carbon contained in the fiber aggregate is preferably carbon nanotubes from the viewpoints of availability, thermal conductivity, and the like.

[0044] In the first embodiment of the rubber molded body of the present disclosure, the content of the granular hollow aggregates of carbon material may be selected appropriately depending on the use of the rubber molded body, the physical properties required for such use (specifically, thermal conductivity, hardness, the aforementioned occupancy rate, etc.), etc.

[0045] [Physical properties of rubber moldings] (thermal conductivity) In the first embodiment of the rubber molded article of the present disclosure, for example, the thermal conductivity is preferably 1.0 W / m·K or more and 100 W / m·K or less.

[0046] The thermal conductivity of the rubber molded article is measured as follows. Specifically, a flat test piece is cut from the target rubber molding, 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 probe of the iPhase Mobile thermal conductivity measuring device (manufactured by iPhase Corporation), and a 50gf weight is placed on it. The thermal conductivity is measured three times in manual mode under the following conditions: 1.41V, 3Hz to 100Hz, 10 divisions, and a measurement time of 2 seconds. The arithmetic mean of the three measurements is the thermal conductivity of the belt.

[0047] (hardness) The first embodiment of the rubber molded article of the present disclosure preferably has an Asker C hardness of 10 or more and 60 or less, and more preferably 15 or more and 50 or less, for example.

[0048] The Asker C hardness of a rubber molded product is the hardness obtained by the Type C test method described in Appendix 2 of JIS K 7312:1996, and is measured using an Asker C hardness tester (for example, Asker Rubber Hardness Tester Type C, manufactured by Kobunshi Keiki Co., Ltd.).

[0049] <Second embodiment of the belt> A second embodiment of a rubber molded body according to the present disclosure is a rubber molded body that includes a rubber foam and a carbon material encapsulated in foam cells of the rubber foam, and has a thermal conductivity of 1.0 W / m·K or more and 100 W / m·K or less and an Asker C hardness of 10 or more and 60 or less. As is clear from the above configuration, the second embodiment of the rubber molded article of the present disclosure has high thermal conductivity and low hardness.

[0050] In the second embodiment of the rubber molded article of the present disclosure, it is preferable that the thermal conductivity is 1.0 W / m·K or more and 100 W / m·K or less, and that the Asker C hardness is 15 or more and 50 or less.

[0051] Similar to the first embodiment of the rubber molded body of the present disclosure, the second embodiment of the rubber molded body of the present disclosure preferably includes a rubber foam and granular hollow aggregates of a carbon material contained in the foam cells of the rubber foam. In the second embodiment, the rubber foam and the granular hollow aggregate of carbon material are synonymous with the rubber foam and the granular hollow aggregate of carbon material described in the first embodiment, respectively, and are similar to the preferred aspects. Also in the second embodiment of the rubber molded article of the present disclosure, the rubber foam may contain well-known additives. Furthermore, the shape of the second embodiment of the rubber molded article of the present disclosure may be determined appropriately depending on the application, similar to the first embodiment of the rubber molded article of the present disclosure.

[0052] [Manufacturing method] The rubber molded article of the present disclosure is produced by the following method. That is, the rubber molded product of the present disclosure can be obtained by preparing a rubber molded product-forming composition containing each component constituting the rubber molded product, pouring the obtained rubber molded product-forming composition into a predetermined mold, and drying it. When the rubber molded product is a layered product, the rubber molded product may be obtained by applying the rubber molded product-forming composition onto a support and drying it. Here, if the support is cylindrical or columnar, an endless belt-like layered product can be formed. The composition for forming a rubber molded body contains a rubber raw material, a granular hollow aggregate of a carbon material, and other components (additives, etc.) that are used as needed.

[0053] In addition, when preparing the composition for forming a rubber molded body, it is preferable to simultaneously produce a granular hollow aggregate of a carbon material. Hereinafter, an example will be described in which a fiber aggregate is used as the granular hollow aggregate of a carbon material. First, a precursor liquid containing a rubber raw material and fibrous carbon is prepared (also referred to as a precursor liquid preparation process), and a fiber aggregate is produced in this precursor liquid system (also referred to as a fiber aggregate production process), thereby obtaining a composition for forming a rubber molded body containing the rubber raw material and the fiber aggregate. The precursor liquid preparation step and the fiber aggregate production step will be described below.

[0054] (Precursor liquid preparation process) In the precursor liquid preparation step, it is preferable to first mix the fibrous carbon with a dispersion medium to prepare a dispersion liquid in which the fibrous carbon is dispersed. Here, examples of the dispersion medium include those that do not dissolve or hardly dissolve the fibrous carbon and rubber raw material. For example, when a silicone rubber raw material is used as the rubber raw material, examples of the dispersion medium include water. Here, the water used as the dispersion medium is not limited as long as it is clean. Examples of water include tap water, well water, ion-exchanged water, and distilled water. The dispersion preferably contains an emulsifier for forming an emulsion. The emulsifier is blended to form a stable emulsion, and the type is not particularly limited, but nonionic emulsifiers are generally preferred. Nonionic surfactants as nonionic emulsifiers include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, ethylene glycol mono-fatty acid esters, propylene glycol mono-fatty acid esters, sorbitan mono-fatty acid esters, sorbitan tri-fatty acid esters, polyoxyethylene sorbitan tri-fatty acid esters, polyoxyethylene mono-fatty acid esters, polyoxyethylene di-fatty acid esters, polyoxyethylene propylene glycol fatty acid esters, and polyoxyethylene polyhydric alcohols. The emulsifier may be used alone or in combination of two or more.

[0055] The obtained dispersion is preferably subjected to a high-pressure dispersion treatment. By performing the high-pressure dispersion treatment, the fibrous carbon in the dispersion is loosened and individually isolated, and further the length of the fibrous carbon in the dispersion is adjusted. Here, the conditions for the high-pressure dispersion treatment may be any conditions that allow the fibrous carbon to be individually isolated and the length of the fibrous carbon to be adjusted to a desired value. For example, the high-pressure dispersion treatment is preferably carried out under a liquid temperature of 25°C or higher and 90°C or lower and a pressure of 1 MPa or higher and 100 MPa or lower (preferably, 3 MPa or higher and 80 MPa or lower). For the high-pressure dispersion treatment, a high-pressure homogenizer or the like is used.

[0056] The length of the fibrous carbon in the dispersion is preferably adjusted to about 1 μm or more and 100 μm or less (more preferably, 3 μm or more and 50 μm or less). Here, the length of the fibrous carbon in the dispersion can be measured by observation with an optical microscope or an electron microscope. The maximum diameter of the fiber aggregate can be controlled by the length of the fibrous carbon in the dispersion liquid. Specifically, the longer the fibrous carbon, the larger the maximum diameter of the aggregate tends to be produced.

[0057] In the precursor liquid preparation step, a rubber raw material is subsequently added to the dispersion liquid obtained as described above to prepare a precursor liquid. The amount of rubber raw material added is preferably about 1% by mass or more and 20% by mass or less (more preferably 3% by mass or more and 15% by mass or less) relative to the total mass of the dispersion.

[0058] (Fiber assembly manufacturing process) In the fiber aggregate manufacturing process, the precursor liquid obtained in the precursor liquid preparation process is stirred by a planetary mixer, and a fiber aggregate is manufactured in the system. By stirring the precursor liquid with a planetary mixer, the fibrous carbon that was individually isolated in the precursor liquid gradually becomes entangled and lumped, producing a fiber aggregate.

[0059] Here, the stirring conditions using the planetary mixer may be any conditions that allow a fiber aggregate having the desired maximum diameter to be obtained. For example, the stirring conditions are preferably such that the temperature of the precursor liquid is 25° C. or higher and 60° C. or lower, and the stirring is carried out for 3 to 90 minutes. The maximum diameter of the fiber aggregate can be controlled by the stirring conditions. Specifically, the longer the stirring time using the planetary mixer, the larger the maximum diameter of the aggregate tends to be.

[0060] In the fiber aggregate manufacturing process, all of the fibrous carbon contained in the precursor liquid may become a fiber aggregate, or some fibrous carbon that does not form a fiber aggregate (i.e., fibrous carbon that is not entangled with each other) may remain along with the fiber aggregate.

[0061] In this manner, a mixture liquid in which the rubber raw material and the fiber aggregate are dispersed is obtained. To the obtained mixture, other components (additives, etc.) are added as needed to obtain a rubber molded body-forming composition to be used in producing a rubber molded body. The obtained mixture may also be diluted with an organic solvent to adjust the viscosity, etc., of the rubber molded body-forming composition.

[0062] Thereafter, when a rubber molded body is produced using the composition for forming a rubber molded body, the rubber molded body of the present disclosure can be obtained by adjusting the drying process of the composition for forming a rubber molded body. In the drying process, first, the rubber raw material in the composition for forming a rubber molded body is reacted at a temperature lower than the temperature at which the dispersion medium evaporates to form a rubber body having the dispersion medium with the fiber aggregates dispersed therein. The formed rubber body is then heated to a temperature higher than the temperature at which the dispersion medium evaporates to remove the dispersion medium, thereby forming a rubber foam and leaving the fiber aggregates in the foam cells of the rubber foam, thereby obtaining a rubber molded body including the rubber foam and the fiber aggregates contained in the foam cells of the rubber foam.

[0063] <Fixing material> The fixing member of the present disclosure has an elastic layer composed of the rubber molded article of the present disclosure described above. Examples of the fixing member of the present disclosure include a roll-shaped member (fixing roll) and a belt-shaped member (fixing belt). The fixing member of the present disclosure preferably has, in this order, a substrate, an elastic layer constituted by the rubber molded article of the present disclosure, and a surface layer. The fixing member of the present disclosure has an elastic layer (the rubber molded body of the present disclosure) that has low hardness and high thermal conductivity, and therefore has high conformability to the irregularities of the recording medium, improving fixing performance, as well as achieving shorter heating times, reduced power consumption, faster fixing speeds, and the like, and is also expected to have a longer lifespan.

[0064] The fixing member of the present disclosure will be described by taking a fixing belt as an example. 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 fixing belt 110 of the present disclosure is not limited to the layer structure shown in FIG. 1, and may be a layer structure in which an adhesive layer is interposed between base layer 110A and elastic layer 110B, a layer structure in which an adhesive layer is interposed between elastic layer 110B and surface layer 110C, a layer structure without elastic layer 110B, a layer structure without surface layer 110C, or a layer structure that combines these layer structures.

[0065] The main components of the fixing belt, which is the fixing member of the present disclosure, will be described in detail below, with the reference numerals omitted.

[0066] [Base material layer] The substrate layer is preferably a layer containing a resin. The resin content in the base layer is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, particularly preferably 80% by mass or more, and most preferably 90% by mass or more, relative to the total mass of the base layer.

[0067] [resin] The resin contained in the base layer 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, etc. may also be used. Among these, polyimide is preferred as the resin.

[0068] 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.

[0069] The tetracarboxylic dianhydride may be either an aromatic or aliphatic compound, but from the viewpoint of heat resistance, an aromatic compound is preferred.

[0070] 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.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] 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).

[0079] [ka]

[0080] 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.

[0081] 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.

[0082] 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)

[0083] From the viewpoint of thermal conductivity and mechanical strength, the thickness of the substrate layer is preferably 30 μm or more and 200 μm or less, more preferably 50 μm or more and 150 μm or less, and particularly preferably 70 μm or more and 120 μm or less.

[0084] [Formation of base layer] The substrate layer can be obtained by preparing a substrate layer-forming coating liquid containing a resin and additives used as needed, applying the obtained substrate layer-forming coating liquid to a cylindrical substrate, and drying it. When the resin is polyimide, the substrate layer can be obtained by preparing a substrate layer-forming coating liquid containing a polyamic acid (a precursor of polyimide resin) and additives used as needed, applying the obtained substrate layer-forming coating liquid to a cylindrical or columnar support, and baking it (i.e., imidization).

[0085] [Elastic layer] The elastic layer is a layer composed of the rubber molded article of the present disclosure. The thickness (film 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. The elastic layer may be formed by applying the above-described method for producing a rubber molded article.

[0086] [Surface 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.

[0087] 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).

[0088] 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.

[0089] 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.

[0090] 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.

[0091] The thickness of the fixing belt is, for example, preferably 0.06 mm or more and 0.90 mm or less, more preferably 0.08 mm or more and 0.70 mm or less, and even more preferably 0.10 mm or more and 0.60 mm or less.

[0092] Although a fixing belt has been described as an example of the fixing member of the present disclosure, the fixing member of the present disclosure may also be a fixing roll. When the fixing member of the present disclosure is a fixing roll, the fixing roll preferably has, for example, a cylindrical or columnar substrate, an elastic layer made of the rubber molded article of the present disclosure, and a surface layer (also called a release layer) in this order.

[0093] [Use of fixing material] The fixing member of the present disclosure is applicable to both a heating belt and a pressure belt if it is a fixing belt, and to both a heating roll and a pressure roll if it is a fixing roll. For example, the heating belt may be either a heating belt that heats by electromagnetic induction or a heating belt that heats from an external heat source. When the fixing belt is used as a heating belt that heats by electromagnetic induction, it is preferable to provide a metal layer (heat-generating layer) that generates heat by electromagnetic induction between the base layer and the elastic layer.

[0094] <Fixing device> The fixing device of the present disclosure has various configurations, and an example thereof is a fixing device that includes a first rotating body and a second rotating body arranged in contact with the outer surface of the first rotating body, and that fixes the toner image by inserting a recording medium having a toner image formed on its surface into the contact portion between the first rotating body and the second rotating body.The fixing member of the present disclosure is applied to at least one of the first rotating body and the second rotating body.

[0095] The following describes the fixing device of the present disclosure: a fixing device equipped with a heating roll and a pressure belt as a first embodiment, a fixing device equipped with a heating belt and a heating roll as a second embodiment, and an electromagnetic induction heating type fixing device equipped with a heating belt and a heating roll as a third embodiment. In the first and second embodiments, the fixing member of the present disclosure can be applied to either the heating belt or the pressure belt. The fixing device of the present disclosure is not limited to the first to third embodiments, and may be a fixing device including a heating roll or a heating belt and a pressure belt. The fixing member of the present disclosure may be applied to either the heating belt or the pressure belt.

[0096] (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).

[0097] 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.

[0098] 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.

[0099] 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).

[0100] 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).

[0101] 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.

[0102] 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 .

[0103] For example, a belt running guide 63 is attached to the holding member 65, and the pressure belt 62 rotates.

[0104] 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.

[0105] 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.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] 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.

[0110] (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).

[0111] 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.

[0112] 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.

[0113] 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.

[0114] Inside the heating pressure roll 89, for example, a halogen heater 89A (an example of a heating means) is provided.

[0115] 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.

[0116] 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.

[0117] That is, for example, the heating belt 84 is heated by the heating pressure roll 89 and the support rolls 90 and 92 .

[0118] 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.

[0119] 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).

[0120] 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.

[0121] 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.

[0122] (Third embodiment of fixing device) A third embodiment of the fixing device will be described with reference to Fig. 4. Fig. 4 is a schematic diagram showing an example of the third embodiment of the fixing device (that is, fixing device 200).

[0123] The fixing device 200 is an electromagnetic induction type fixing device that includes a belt 220 having a metal layer. In the fixing device 200, the belt 220 is used as the fixing belt of the present disclosure. 4, a pressure roll (pressure member) 211 is disposed so as to pressurize a portion of the belt 220, and from the viewpoint of efficient fixing, a contact area (nip) is formed between the belt 220 and the pressure roll 211, and the belt 220 is curved to fit the circumferential surface of the pressure roll 211. Also, from the viewpoint of ensuring the releasability of the recording medium, a bent portion is formed at the end of the contact area (nip) where the belt is bent.

[0124] The pressure roll 211 is configured such that an elastic layer 211B made of silicone rubber or the like is formed on a base material 211A, and a release layer 211C made of a fluorine-based compound is further formed on the elastic layer 211B.

[0125] An opposing member 213 is disposed inside the belt 220 at a position facing the pressure roll 211. The opposing member 213 is made of metal, heat-resistant resin, heat-resistant rubber, or the like, and has a pad 213B that comes into contact with the inner circumferential surface of the belt 220 to locally increase pressure, and a support 213A that supports the pad 213B.

[0126] An electromagnetic induction heating device 212 incorporating an electromagnetic induction coil (excitation coil) 212a is provided at a position facing the pressure roll 211 (an example of a pressure member) across the belt 220. The electromagnetic induction heating device 212 applies an alternating current to the electromagnetic induction coil, changing the generated magnetic field with an excitation circuit, and generates eddy currents in a metal layer (e.g., an electromagnetic induction metal layer) (not shown) of the belt 220. The eddy currents are converted into heat (Joule heat) by the electrical resistance of the metal layer (not shown), and as a result, the surface of the belt 220 generates heat. The position of the electromagnetic induction heating device 212 is not limited to the position shown in FIG. 4, and may be installed, for example, upstream of the contact area of the belt 220 in the rotation direction B, or may be installed inside the belt 220.

[0127] In the fixing device 200, a driving force is transmitted from a driving device to a gear fixed to the end of the belt 220, causing the belt 220 to rotate by itself in the direction of arrow B, and as the belt 220 rotates, the pressure roll 211 rotates in the opposite direction, i.e., in the direction of arrow C. The recording medium 215 on which the unfixed toner image 214 is formed is passed through the contact area (nip) between the belt 220 and the pressure roll 211 in the fixing device 200 in the direction of arrow A, and the unfixed toner image 214 is in a molten state and pressure is applied to fix it to the recording medium 215.

[0128] <Image forming device> Next, the image forming apparatus of the present disclosure will be described. The image forming apparatus of 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 of the present disclosure is applied as the fixing means.

[0129] In the image forming apparatus of the present disclosure, the fixing device may be formed as a cartridge that is detachably attached to the image forming apparatus. In other words, the image forming apparatus of the present disclosure may include the fixing device of the present disclosure as a component of a process cartridge.

[0130] The image forming apparatus of the present disclosure will be described below with reference to the drawings. FIG. 5 is a schematic diagram showing the configuration of the image forming apparatus of the present disclosure.

[0131] 5, image forming apparatus 100 of 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).

[0132] 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.

[0133] 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.

[0134] 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.

[0135] 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.

[0136] 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).

[0137] 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.

[0138] The intermediate transfer belt 15 is driven (rotated) in a circular manner in the direction B shown in Fig. 5 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.

[0139] 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 7.5Ωcm or more 10 8.5 It is a sponge-like cylindrical roll with a resistance of less than Ωcm.

[0140] 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.

[0141] 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 .

[0142] 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.

[0143] 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.

[0144] 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.

[0145] 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.

[0146] 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.

[0147] 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.

[0148] Furthermore, the image forming apparatus of 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 this 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.

[0149] Next, the basic image forming process of the image forming apparatus of 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.

[0150] 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.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] 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.

[0155] 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.

[0156] 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.

[0157] 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]

[0158] 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.

[0159] Example 1 (Formation of base layer) A coating solution for forming a base layer containing polyamic acid (solid content: 18% by mass) was applied onto a cylindrical mold, and the resulting coating film was baked at 380°C to form a cylindrical base layer (film thickness: 80 μm).

[0160] (Formation of elastic layer) A dispersion was prepared by mixing 65 parts by mass of water and 30 parts by mass of carbon nanotubes (Showa Denko K.K.), to which 5 parts by mass of an emulsifier (a 1:3 mixture of polyoxyethylene dilaurate and polyoxyethylene dioleate (Takemoto Yushi Co., Ltd.)) was added. The resulting dispersion was subjected to a high-pressure dispersion treatment using a high-pressure homogenizer (HC3, Sanmaru Kikai Kogyo Co., Ltd.) under conditions of 45°C liquid temperature, 50 MPa, and 3 cycles (i.e., 3 passes through the valve). Next, a precursor liquid was prepared by adding 50 parts by mass of a silicone rubber stock solution (X34-1053 manufactured by Shin-Etsu Chemical Co., Ltd.) to 50 parts by mass of the dispersion liquid after the high-pressure dispersion treatment. The obtained precursor liquid was stirred for 10 minutes in a planetary mixer (Aikosha Seisakusho Co., Ltd., ACM-5LVT) under conditions of a liquid temperature of 25°C and vacuum drawing. As a result, an elastic layer-forming coating liquid (rubber molded body-forming composition) was obtained, which contained 33 mass % of aggregates (i.e., fiber aggregates) formed by entanglement of a plurality of carbon nanotubes in the solid content. Next, the obtained coating liquid for forming an elastic layer was applied onto the base layer to form a coating film, and the coating film was heated at 110°C for 30 minutes to form an elastic layer with a thickness of 450 µm. The formed elastic layer was composed of a rubber molded body including a rubber foam and a fiber aggregate encapsulated in the foam cells of the rubber foam.

[0161] (Formation of surface layer) A PFA tube (Gunze Co., Ltd.) with a thickness of 35 μm was placed on the elastic layer and heated at 200° C. for 120 minutes to form a surface layer made of a fluororesin tube.

[0162] Through the above steps, a fixing belt was obtained.

[0163] <Examples 2 and 3> Fixing belts of Examples 2 and 3 were obtained in the same manner as in Example 1, except that the method of forming the elastic layer in Example 1 was changed as follows. That is, in forming the elastic layer in Example 1, the temperature to which the coating film was heated after applying the coating liquid for forming the elastic layer onto the substrate layer to form the coating film was changed to 100°C (Example 2) or 120°C (Example 3), respectively, and the elastic layer was formed in the same manner as in Example 1.

[0164] <Examples 4 to 6> Fixing belts of Examples 4 to 6 were obtained in the same manner as in Example 1, except that the method of forming the elastic layer in Example 1 was changed as follows. That is, in forming the elastic layer in Example 1, the elastic layer was formed in the same manner as in Example 1, except that the time for heating the coating film after applying the coating liquid for forming the elastic layer onto the substrate layer to form a coating film was changed to 120 minutes (Example 4), 15 minutes (Example 5), or 10 minutes (Example 6).

[0165] <Examples 7 to 10> Fixing belts of Examples 7 to 10 were obtained in the same manner as in Example 1, except that the method of forming the elastic layer in Example 1 was changed as follows. That is, in forming the elastic layer in Example 1, the stirring time of the dispersion liquid and the temperature at which the coating film was heated after applying the coating liquid for forming the elastic layer onto the substrate layer to form a coating film were changed as follows, except that the elastic layer was formed in the same manner as in Example 1. Example 7: Stirring time: 20 minutes, heating temperature: 100°C Example 8: Stirring time 5 minutes, heating temperature 140°C Example 9: Stirring time 40 minutes, heating temperature 105°C Example 10: Stirring time 3 minutes, heating temperature 140°C

[0166] <Examples 11 to 13> Fixing belts of Examples 11 to 13 were obtained in the same manner as in Example 1, except that the method of forming the elastic layer in Example 1 was changed as follows. That is, in forming the elastic layer of Example 1, the amount of emulsifier added when preparing the dispersion was changed to 2 parts by mass (Example 11), 7 parts by mass (Example 12), or 9 parts by mass (Example 13), respectively, and the elastic layer was formed in the same manner as in Example 1.

[0167] <Examples 14 and 15> Fixing belts of Examples 14 and 15 were obtained in the same manner as in Example 1, except that the method of forming the elastic layer in Example 1 was changed as follows. That is, in forming the elastic layer of Example 1, the amount of carbon nanotubes used in preparing the dispersion was changed to 15 parts by mass (Example 14) or 50 parts by mass (Example 15), respectively, and the elastic layer was formed in the same manner as in Example 1.

[0168] Example 16 A fixing belt of Example 16 was obtained in the same manner as in Example 1, except that the method of forming the elastic layer in Example 1 was changed as follows.

[0169] (Formation of elastic layer) -Production of spherical graphene- A graphene film was generated and deposited in a 20 μm particle diameter template made of CaCO3 (Shiraishi Industrial Co., Ltd.) using a CVD device (Ishikawa Sangyo Co., Ltd.), and then the template was removed by washing with hydrochloric acid to obtain spherical graphene. -Film formation- A dispersion liquid obtained by dispersing 30 parts by mass of the spherical graphene described above in 70 parts by mass of water was used, and 50 parts by mass of a silicone rubber concentrate (X34-1053 manufactured by Shin-Etsu Chemical Co., Ltd.) was added to 50 parts by mass of this dispersion liquid to obtain a coating liquid for forming an elastic layer (a composition for forming a rubber molded body). An elastic layer was formed in the same manner as in Example 1, except that the obtained coating liquid for forming an elastic layer was used.

[0170] <Comparative Example 1> A fixing belt of Comparative Example 1 was obtained in the same manner as in Example 1, except that the method of forming the elastic layer in Example 1 was changed as follows. That is, an elastic layer was formed in the same manner as in Example 1, except that a silicone rubber stock solution (X34-1053 manufactured by Shin-Etsu Chemical Co., Ltd.) was used as it was as the coating liquid for forming the elastic layer.

[0171] <Comparative Example 2> A fixing belt of Comparative Example 2 was obtained in the same manner as in Example 1, except that the method of forming the elastic layer in Example 1 was changed as follows. That is, the elastic layer was formed in the same manner as in Example 1, except that the dispersion liquid used in Example 1 was not used, and instead a coating liquid for forming an elastic layer obtained by adding azobisisobutyronitrile, a foaming agent, to a silicone rubber stock solution (X34-1053 manufactured by Shin-Etsu Chemical Co., Ltd.) was used.

[0172] <Comparative Example 3> A fixing belt of Comparative Example 3 was obtained in the same manner as in Example 1, except that the method of forming the elastic layer in Example 1 was changed as follows. That is, an elastic layer was formed in the same manner as in Example 1, except that the water used in preparing the dispersion was changed to butyl acetate.

[0173] <Measurement of thermal conductivity> The thermal conductivity of the elastic layer obtained in each example was measured according to the method described above.

[0174] <Measurement of Asker C hardness> The Asker C hardness of the elastic layer obtained in each example was measured according to the method described above.

[0175] <Evaluation of compression durability> For the fixing belt obtained in each example, an evaluation fixing unit was prepared in which the fixing belt was interposed between a heating roll (heating pressing roll) and a pressure roll as shown in FIG. 4. Using the prepared evaluation fixing unit, the heating roll and the pressure roll were pressed against each other, and with the elastic layer thickness of the fixing belt pressed in to 50%, the surface temperature of the pressure roll was set to 160 ° C, and at a rotational speed corresponding to a linear speed of 255 mm / second, the pressure roller was continuously driven for a time equivalent to 450,000 sheets of A4 paper passing through. After continuous driving, the fixing belt was removed from the evaluation fixing unit, and the entire surface of the removed fixing belt was visually inspected to evaluate for breakage of the elastic layer. A: The number of breakage points of the elastic layer of the fixing belt is 5 or less B: The number of breakage points of the elastic layer of the fixing belt is 6 or more and 10 or less C: The number of breakage points of the elastic layer of the fixing belt is 11 or more

[0176] <Evaluation of paper unevenness followability> The fixing belt obtained in each example was attached to the fixing device of an image forming apparatus (manufactured by Fuji Xerox Co., Ltd.: Versant 3100 Press). Using this image forming apparatus, 300,000 solid images with an image density of 100% at Cin100% were output on A4 paper. As the conditions for fixing, the output speed (printing speed) was 60 sheets per minute. Also, as the A4 paper, embossed paper with large surface unevenness (Resac 66 manufactured by Tokushu Tokai Pulp Co., Ltd.) was used. After the above output, the fixing belt was removed, and the surface of the removed fixing belt was visually observed to evaluate for offset. Offset was evaluated according to the following criteria. A: No offset is observed on the fixing belt. B: Slight offset (1 to 3 locations) is observed on the fixing belt. C: Offset is observed in some parts of the fixing belt (4 to 7 locations).

[0177] [Table 1]

[0178] The above results show that the fixing belt of this example has higher thermal conductivity and superior bending durability than the fixing belt of the comparative example, and also superior compression durability and paper irregularity followability. [Explanation of symbols]

[0179] 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 200 Fixing device 211 Pressure Roll 212 Electromagnetic induction heating device 220 Belt

Claims

1. A fixing member having an elastic layer made of a rubber molded body including a rubber foam and granular hollow aggregates of a carbon material enclosed in foam cells of the rubber foam.

2. 2. The fixing member according to claim 1, wherein a diameter X of the foam cells is larger than a maximum diameter Y of the granular hollow aggregate of the carbon material, and the foaming rate distribution of the rubber foam has a variation of 20% or less.

3. 3. The fixing member according to claim 2, wherein a diameter X of the foamed cells is more than 1.0 times and not more than 50 times a maximum diameter Y of the granular hollow aggregate of the carbon material.

4. 4. The fixing member according to claim 1, wherein the rubber foam has an open cell ratio of less than 100%.

5. The fixing member according to claim 4 , wherein the rubber foam has an open cell ratio of 50% or less.

6. 6. The fixing member according to claim 1, wherein the occupancy rate of the granular hollow aggregates of the carbon material in the foam cells is more than 0% and less than 100%.

7. The fixing member according to claim 6 , wherein the occupancy rate of the granular hollow aggregates of the carbon material in the foam cells is 5% or more and 50% or less.

8. 8. The fixing member according to claim 1, wherein the granular hollow aggregate of the carbon material is a granular hollow aggregate formed by entanglement of a plurality of fibrous carbon fibers with one another.

9. 9. The fixing member according to claim 1, wherein the fixing member has a thermal conductivity of 1.0 W / m·K or more and 100 W / m·K or less, and an Asker C hardness of 10 or more and 60 or less.

10. a first rotating body; and a second rotating body arranged in contact with an outer surface of the first rotating body, At least one of the first rotating body and the second rotating body is the fixing member according to any one of claims 1 to 9, a fixing device that fixes a toner image formed on a surface of the recording medium by inserting the recording medium through a contact portion between the first rotating body and the second rotating body;

11. 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 charged surface of the 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 onto a surface of a recording medium; a fixing unit configured as the fixing device according to claim 10 for fixing the toner image onto the recording medium; An image forming apparatus comprising:

Images