Fixing member, fixing device, and image forming apparatus

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 molded products, there is a demand for rubber molded products that are soft and have high thermal conductivity. For example, in image forming apparatuses using electrophotography (such as photocopiers, facsimile machines, and printers), an example is the elastic layer of the fixing member used to fix the toner image formed on the recording medium onto the recording medium.

[0003] Furthermore, carbon nanotubes, which are carbon materials, can be cited as one of the thermal conductive materials. As a functional film using carbon nanotubes, for example, Patent Document 1 discloses a functional film containing aggregates made of entangled carbon nanotubes, with a diameter of 50 μm or less, a height of less than 5 μm, and a height-to-diameter ratio (height / diameter) of less than 0.1. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2019-140105 [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] The object of this 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 case in which a carbon material is contained inside the rubber foam. [Means for solving the problem]

[0006] The following embodiments are included as specific means for solving the aforementioned problems. <1> A rubber molded article comprising a rubber foam and granular hollow aggregates of carbon material enclosed within the foam cells of the rubber foam.

[0007] <2> The diameter X of the foam cell is greater than the maximum diameter Y of the granular hollow aggregate of the carbon material, and the variation in the foaming rate distribution of the rubber foam is 20% or less. <1> The rubber molded body described above. <3> The foam cell diameter X is greater than 1.0 times and less than or equal to 50 times the maximum diameter Y of the granular hollow aggregate of the carbon material. <2> The rubber molded body described above. <4> The continuous cell ratio of the rubber foam is less than 100%. <1> ~ <3> A rubber molded body as described in any one of the following. <5> The continuous cell ratio of the rubber foam is 50% or less. <4> The rubber molded body described above. <6> The occupancy rate of the granular hollow aggregate of carbon material in the foam cell is greater than 0% and less than 100%. <1> ~ <5> A rubber molded body as described in any one of the following. <7> The occupancy rate of the granular hollow aggregate of carbon material in the foam cell is 5% or more and 50% or less. <6> The rubber molded body described above. <8> The granular hollow aggregate of the carbon material is a granular hollow aggregate formed by multiple fibrous carbons intertwined with each other. <1> ~ <7> A rubber molded body as described in any one of the following. <9> The material comprises a rubber foam and a carbon material enclosed within the foam cells of the rubber foam, A rubber molded body 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> A fixing member having an elastic layer made of a rubber molded body described in any one of the above. <11> It comprises a first rotating body and a second rotating body positioned in contact with the outer surface of the first rotating body, At least one of the first rotating body and the second rotating body <10> The fixing member described above, A fixing device for fixing a toner image by inserting a recording medium on which a toner image has been formed on its surface into the contact area between the first rotating body and the second rotating body. <12> Image holder and, A charging means for charging the surface of the image holder, An electrostatic latent image forming means for forming an electrostatic latent image on the charged surface of the image holder, A developing means that develops an electrostatic latent image formed on the surface of the image holder with a developer containing toner to form a toner image, A transfer means for transferring the toner image onto the surface of a recording medium, The toner image is fixed onto the recording medium. <11> Fixing means comprising the fixing device described above, An image forming apparatus equipped with the following features. [Effects of the Invention]

[0009] <1> , <6> , <8> , or <9> According to the invention, a rubber molded article is provided that has a higher thermal conductivity and lower hardness compared to a case in which a carbon material is contained inside the rubber foam. <2> According to the invention, a rubber molded article is provided that has high thermal conductivity and low hardness compared to the case where the diameter X of the foam cells is larger than the maximum diameter Y of the granular hollow aggregate of the carbon material, and the variation in the foaming rate distribution of the rubber foam is more than 20%. <3> According to the invention, a rubber molded article is provided that has high thermal conductivity and low hardness compared to cases where 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 carbon material. <4> According to the invention, a rubber molded article is provided that has a higher thermal conductivity and lower hardness compared to the case where the continuous cell ratio of the rubber foam is 100%. <5> According to the invention, a rubber molded article is provided that has high thermal conductivity and low hardness compared to a rubber foam with a cell density of more than 50%. <7> According to the invention, a rubber molded article is provided that has high thermal conductivity and low hardness compared to cases where the occupancy rate of granular hollow aggregates of carbon material in a foam cell is less than 5% or more than 50%.

[0010] According to the invention according to <10>, a fixing member having an elastic layer with a high thermal conductivity and a low hardness is provided as compared with the case of having an elastic layer composed of a rubber molded body containing a carbon material inside a rubber foam. According to the invention according to <11> or <12>, a fixing device or an image forming device provided with a fixing member having an elastic layer with a high thermal conductivity and a low hardness is provided as compared with the case of having an elastic layer composed of a rubber molded body containing a carbon material inside a rubber foam.

Brief Description of the Drawings

[0011] [Figure 1] It is a schematic cross-sectional view showing an example of a fixing belt which is a fixing member of the present disclosure. [Figure 2] It is a schematic configuration diagram showing an example of a first embodiment of a fixing device of the present disclosure. [Figure 3] It is a schematic configuration diagram showing an example of a second embodiment of a fixing device of the present disclosure. [Figure 4] It is a schematic configuration diagram showing an example of a third embodiment of a fixing device of the present disclosure. [Figure 5] It is a schematic configuration diagram showing an example of an image forming device of the present disclosure.

Modes for Carrying Out the Invention

[0012] Hereinafter, embodiments of the present invention will be described. These descriptions and examples are illustrative of the embodiments and do not limit the scope of the embodiments.

[0013] In the numerical ranges described step by step in this specification, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of the numerical ranges described in other step-by-step descriptions. Also, in the numerical ranges described in this specification, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples.

[0014] In this specification, each component may contain multiple types of the relevant substance. 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, unless otherwise specified, it refers to the total amount of those multiple substances present in the composition.

[0015] In this specification, unless otherwise specified, the term "rubber molded articles of this disclosure" refers to both the first and second embodiments described later.

[0016] <First Embodiment of a Rubber Molded Body> A first embodiment of the rubber molded article of this disclosure is a rubber molded article comprising a rubber foam and granular hollow aggregates of carbon material enclosed within the foam cells of the rubber foam.

[0017] In this specification, "granular hollow aggregate of carbon material" refers to a granular aggregate formed by the combination of carbon materials, where the granular hollow aggregate contains carbon material and voids between the carbon materials (i.e., voids that form a hollow state). Examples of carbon material include carbon fiber, graphene, and fullerene. If the carbon material is carbon fiber, the granular hollow aggregate of carbon material is preferably a granular hollow aggregate formed by the entanglement of multiple fibrous carbons. If the carbon fiber is graphene, sp 2 It is preferable that the material is a granular hollow aggregate formed by combining multiple sheet-like structures (i.e., graphene) consisting of a single layer in which carbon atoms bonded together are arranged in a planar manner.

[0018] The first embodiment of the rubber molded article of this disclosure has high thermal conductivity and low hardness due to the above configuration. The reason for this is presumed to be as follows. Rubber foam is used to achieve low hardness in molded rubber products. However, when thermal conductive materials (such as carbon nanotubes) are incorporated into this rubber foam, while the thermal conductivity improves, the hardness also increases, which presents a challenge. In the first embodiment of the rubber molded article of this disclosure, granular hollow aggregates of carbon material are embedded not inside the rubber foam, but within the foam cells of the rubber foam. With this configuration, the thermal conductivity can be improved without including a thermal conductive material inside the rubber foam. Therefore, it is presumed that a rubber molded article exhibiting high thermal conductivity can be obtained while achieving the low hardness that comes with using rubber foam.

[0019] [Preferred embodiment of the first embodiment of the rubber molded body] In the first embodiment of the rubber molded article of this 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 aggregate of the carbon material, and that the variation in the foaming rate distribution of the rubber foam is 20% or less. In particular, from the viewpoint of achieving both high thermal conductivity and low hardness, it is more preferable that the foam cell diameter X is more than 1.0 times and 50 times or less the maximum diameter Y of the granular hollow aggregate of carbon material, and even more preferable that it is 10 times or more and 30 times or less. Furthermore, the smaller the variation in the foaming rate distribution of the rubber foam, the better; it is more preferably 15% or less, even more preferably 10% or less, particularly preferably 5% or less, and most preferably 0%.

[0020] In the first embodiment of the rubber molded article of this disclosure, from the viewpoint of achieving both high thermal conductivity and low hardness, the cell density 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 proportion of open cells (i.e., bubbles) in the foamed rubber. Here, open cells refer to bubbles (also called open bubbles) that are partially exposed to the surface of the foamed rubber (molded rubber) and are connected to the outside of the foamed rubber. Foamed cells include closed cells in addition to open cells, and closed cells refer to bubbles that are entirely surrounded by walls (i.e., the solid phase of the foamed rubber).

[0021] In the first embodiment of the rubber molded article of this disclosure, from the viewpoint of achieving both high thermal conductivity and low hardness, the occupancy rate of granular hollow aggregates of carbon material in the foam cell is preferably more than 0% and less than 100%, and more preferably 5% or more and 50% or less. Here, the occupancy rate of granular hollow aggregates of carbon material in a foam cell refers to the proportion of the size of the foam cell (i.e., the bubble) that is occupied by the granular hollow aggregates of carbon material contained within the foam cell. Note that an occupancy rate of less than 100% means that, in addition to the granular hollow aggregates of carbon material, gas (for example, air) is also present in the foam cell.

[0022] Here, the diameter X of the foam cell, the maximum diameter Y of the granular hollow aggregate of carbon material, the variation in the foaming rate distribution of the rubber foam, the continuous cell rate, and the occupancy rate of the granular hollow aggregate of carbon material in the foam cell are determined by the following method. The rubber molded body is cut in any direction using a microtome to obtain a cross-section for measurement. If the rubber molded body is a layered material, it is preferable that the cross-section for measurement be a cross-section obtained by cutting the layered material in the thickness direction. The obtained cross-section for measurement is observed with an electron microscope (e.g., SU-70 manufactured by Hitachi High-Tech 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 is used to determine the diameter X of the foam cell, the maximum diameter Y of the granular hollow aggregate of carbon material, the continuous cell ratio, and the occupancy rate of the granular hollow aggregate of carbon material in the foam cell. Specifically, the diameter X of the foam cell is the arithmetic mean of the largest diameters of foam cells (i.e., bubbles) in the analyzed cross-sectional image. If there are many connected bubbles, the connected bubbles can be pseudo-separated into independent bubbles based on their shape, etc., and the largest diameter of these independent bubbles can be determined. That is, if a connected bubble is a shape of two bubbles connected together, it can be pseudo-separated into two, and the maximum diameter of each of the two independent bubbles can be determined. To determine the variation in the foaming rate distribution of rubber foam, first, divide the cross-sectional image into 10 equal parts and calculate the bubble rate in each divided region. By finding the difference between the maximum and minimum values ​​of the calculated bubble rate, the variation in the bubble rate distribution can be determined. Note that the bubble rate is calculated as (total bubble area / total area of ​​one region) × 100. The maximum diameter Y of the granular hollow aggregate of carbon material is defined as the arithmetic mean of the maximum diameters of the granular hollow aggregate of carbon material contained within the foam cell in the analyzed cross-sectional image. The continuous cell ratio is calculated as: Total area of ​​continuous cells in the analyzed cross-sectional image / Total area of ​​foam cells (i.e., bubbles) in the analyzed cross-sectional image × 100. The occupancy rate of granular hollow aggregates of carbon material in foam cells is determined by extracting foam cells containing granular hollow aggregates of carbon material from the analyzed cross-sectional images, calculating the occupancy rate for each foam cell using the formula: Area of ​​granular hollow aggregates of carbon material / Area of ​​foam cell × 100, and then taking the arithmetic mean.

[0023] The following describes the granular hollow aggregates of rubber foam and carbon material used in the first embodiment of the rubber molded article of this disclosure.

[0024] [Rubber foam] A rubber foam refers to a structure made of rubber material that contains at least internal cavities (i.e., foam cells). Examples of rubber materials include silicone rubber, fluororubber, and fluorosilicone rubber. Among these, silicone rubber and fluororubber are selected from the viewpoint of heat resistance and thermal conductivity, with silicone rubber being preferred.

[0025] Examples of silicone rubber include RTV silicone rubber, HTV silicone rubber, and liquid silicone rubber. Specifically, examples include polydimethyl silicone rubber (MQ), methyl vinyl silicone rubber (VMQ), methylphenyl silicone rubber (PMQ), and fluorosilicone rubber (FVMQ).

[0026] As for the silicone rubber, those with an addition reaction type as the crosslinking mechanism are preferred. Furthermore, various types of functional groups are known for silicone rubber, and dimethyl silicone rubber having methyl groups, methylphenyl silicone rubber having methyl and phenyl groups, and vinyl silicone rubber having vinyl groups (vinyl group-containing silicone rubber) are preferred. Furthermore, as the silicone rubber, vinyl silicone rubber having vinyl groups is more preferred, and silicone rubber having an organopolysiloxane structure having vinyl groups and a hydrogen organopolysiloxane structure having hydrogen atoms (SiH) bonded to silicon atoms is even more preferred.

[0027] Examples of fluororubbers include vinylidene fluoride rubber, tetrafluoroethylene / propylene rubber, tetrafluoroethylene / perfluoromethyl vinyl ether rubber, phosphophazene rubber, and fluoropolyether.

[0028] The rubber material used in the rubber foam preferably has silicone rubber as its main component (i.e., it contains 50% or more by mass of silicone rubber relative to the total mass of the rubber material). The silicone rubber content is more preferably 90% by mass or more, even more preferably 99% by mass or more, and may be 100% by mass, based on the total mass of rubber material contained in the rubber foam.

[0029] In addition to the rubber material described above, the rubber foam may also 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.). In addition, inorganic fillers include carbon materials such as carbon black and carbon nanotubes, but if the rubber foam contains carbon materials, it is preferable that they be used in a manner that does not impair the effects of the rubber molded article of this disclosure.

[0030] There are no particular restrictions on the shape and size of the rubber foam; they should be determined appropriately according to the intended use.

[0031] The diameter of the foam cells in the rubber foam can be determined appropriately according to the intended use of the rubber molded product and the physical properties required for that use. The diameter of the foam cells in the rubber foam is preferably, for example, 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 should be determined appropriately according to the intended use of the rubber molded product and the physical properties required for that use.

[0033] [Granular hollow aggregate of carbon material] A first embodiment of the rubber molded article of this disclosure comprises a foam cell of rubber foam containing a granular hollow aggregate of carbon material. Granular hollow aggregates of carbon materials act as thermal conductors.

[0034] The maximum diameter of the granular hollow aggregate of carbon material is preferably smaller than the diameter of the foam cell (the foam cell diameter X as described above), from the viewpoint of being enclosed within the foam cell. For example, the maximum diameter of the granular hollow aggregate of 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 granular hollow aggregate of carbon material can be any shape that fits within the foam cell, and there are no particular restrictions on its shape. The granular hollow aggregate of carbon material can be, for example, spherical, ellipsoidal, or of any irregular shape.

[0036] From the viewpoints of mechanical strength, elasticity, and manufacturing, the ratio of the minor axis B to the major axis A of the granular hollow aggregate of carbon material (minor axis B / major axis A) 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 by the following method. Similar to measuring the diameter X of foam cells in a rubber molded product, the measurement cross-section is observed with an electron microscope, and the longest axis A of the granular hollow aggregate of carbon material within the foam cell, and the longest axis B in the direction perpendicular to the long axis A are measured. Ten samples of the granular hollow aggregate of carbon material are measured, and the arithmetic mean values ​​of the 10 samples are taken for both the "long axis A" and the "short axis B".

[0038] The granular hollow aggregate of carbon material is preferably a granular hollow aggregate formed by the entanglement of multiple fibrous carbons, or a granular hollow aggregate formed by the combination of multiple graphenes. From the viewpoint of ease of availability and the ability to obtain high thermal conductivity, a granular hollow aggregate formed by the entanglement of multiple fibrous carbons (hereinafter also referred to as a fibrous aggregate) is more preferable.

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

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

[0041] The length and diameter of the fibrous carbon constituting the fiber aggregate are measured by the following method. Similar to measuring the diameter X of foam cells in a rubber molded product, the measurement cross-section is observed with an electron microscope to measure the length and diameter of the fibrous carbon constituting the fiber aggregate. Ten measurement samples of the fiber aggregate are used, and measurements are taken on two fibrous carbons per fiber polymer. The "length of the fibrous carbon constituting the fiber aggregate" and the "diameter of the fibrous carbon constituting the fiber aggregate" are calculated as the arithmetic mean of the 20 measurements (10 samples × 2 carbons).

[0042] The number of fibrous carbon atoms contained in the fiber aggregate is not particularly limited; it only needs to be multiple (i.e., two or more).

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

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

[0045] [Physical properties of rubber molded products] (Thermal conductivity) In the first embodiment of the rubber molded article of this disclosure, it is preferable, for example, that the thermal conductivity is 1.0 W / m·K or more and 100 W / m·K or less.

[0046] The thermal conductivity of a rubber molded body is measured as follows: Specifically, a flat test piece is cut from the target rubber molded body, and the thermal conductivity is determined from the thermal diffusivity in the thickness direction of the test piece. More precisely, the test piece is placed on the probe of the iPhase Mobile thermal conductivity measuring device (manufactured by iPhase Corporation), a 50gf weight is placed on top, and the thermal conductivity is measured three times in manual mode under the conditions of 1.41V, 3Hz~100Hz divided into 10 sections, and a measurement time of 2 seconds. The arithmetic mean of the three measured values ​​is taken as the thermal conductivity of the belt.

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

[0048] The Asker C hardness of a rubber molded article is the hardness obtained by the Type C test method described in Annex 2 of JIS K 7312:1996, and is measured using an Asker C hardness tester (e.g., Asker Rubber Hardness Tester Type C, manufactured by Polymer Instruments Co., Ltd.).

[0049] <Second embodiment of the belt> A second embodiment of the rubber molded article of the present disclosure is a rubber molded article comprising a rubber foam and a carbon material enclosed within the foam cells of the rubber foam, wherein the thermal conductivity is 1.0 W / m·K or more and 100 W / m·K or less, and the Asker C hardness is 10 or more and 60 or less. As is clear from the above configuration, the second embodiment of the rubber molded article of this 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 the Asker C hardness is 15 or more and 50 or less.

[0051] A second embodiment of the rubber molded article of the present disclosure preferably includes a rubber foam and granular hollow aggregates of carbon material enclosed within the foam cells of the rubber foam, similar to the first embodiment of the rubber molded article of the present disclosure. In the second embodiment, the rubber foam and the granular hollow aggregate of carbon material are the same as the rubber foam and the granular hollow aggregate of carbon material described in the first embodiment, respectively, and are the same as in the preferred embodiment. Furthermore, in the second embodiment of the rubber molded article of this disclosure, the rubber foam may also contain well-known additives. Furthermore, the shape of the second embodiment of the rubber molded article of this disclosure may be determined as appropriate depending on the application, similar to the first embodiment of the rubber molded article of this disclosure.

[0052] [Manufacturing method] The rubber molded articles of this disclosure are manufactured by the following method. In other words, the rubber molded article of this disclosure is obtained by preparing a rubber molded article forming composition containing each component constituting the rubber molded article, pouring the obtained rubber molded article forming composition into a predetermined mold, and drying it. If the rubber molded article is a layered article, the rubber molded article may be obtained by applying the rubber molded article forming composition onto a support and drying it. If the support is cylindrical or columnar, an endless belt-shaped layered article can be formed. The composition for forming rubber molded articles includes rubber raw materials, granular hollow aggregates of carbon material, and other components (additives, etc.) used as needed.

[0053] Furthermore, when preparing the above-mentioned rubber molded article formation composition, it is preferable to also produce granular hollow aggregates of carbon material. The following explanation will take the case where fiber aggregates are used as granular hollow aggregates of carbon material as an example. First, a precursor liquid containing rubber raw materials and fibrous carbon is prepared (also called the precursor liquid preparation step), and a fiber aggregate is manufactured in this precursor liquid system (also called the fiber aggregate manufacturing step) to obtain a rubber molded article forming composition containing rubber raw materials and fiber aggregate. The following describes the precursor liquid preparation process and the fiber assembly manufacturing process.

[0054] (Preparation process for precursor solution) In the precursor solution preparation step, it is preferable to first mix fibrous carbon with a dispersion medium to prepare a dispersion in which fibrous carbon is dispersed. Here, the dispersion medium can be one that does not dissolve or dissolves fibrous carbon and rubber raw materials in any way. For example, when silicone rubber raw materials are used as the rubber raw materials, water can be used as the dispersion medium. Here, the water used as the dispersion medium only needs to be clean, and its type is not limited. Examples of water include tap water, well water, ion-exchanged water, and distilled water. Furthermore, the dispersion preferably contains an emulsifier for forming an emulsion. The emulsifier is added to form a stable emulsion, and its type is not particularly limited, but generally a nonionic emulsifier is preferred. Examples of nonionic surfactants used as nonionic emulsifiers include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, ethylene glycol monofatty acid esters, propylene glycol monofatty acid esters, sorbitan monofatty acid esters, sorbitan trifatty acid esters, polyoxyethylene sorbitan trifatty acid esters, polyoxyethylene monofatty acid esters, polyoxyethylene difatty 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 types.

[0055] It is preferable to subject the resulting dispersion to high-pressure dispersion treatment. High-pressure dispersion treatment breaks down the fibrous carbon in the dispersion, allowing it to be isolated individually, and further, the length of the fibrous carbon in the dispersion is adjusted. Here, the conditions for the high-pressure dispersion treatment should be such that the fibrous carbon is individually isolated and the length of the fibrous carbon can be adjusted to the desired value. For example, the high-pressure dispersion treatment is preferably carried out at a pressure of 1 MPa to 100 MPa (preferably 3 MPa to 80 MPa) with a liquid temperature of 25°C to 90°C. High-pressure dispersion processing uses equipment such as high-pressure homogenizers.

[0056] Furthermore, it is preferable that the length of the fibrous carbon in the dispersion be adjusted to approximately 1 μm to 100 μm (preferably 3 μm to 50 μm). 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; specifically, longer fibrous carbon tends to produce aggregates with larger maximum diameters.

[0057] In the precursor solution preparation step, rubber raw materials are then added to the dispersion obtained as described above to prepare the precursor solution. The amount of rubber raw material added is preferably 1% by mass or more and 20% by mass or less (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 in a planetary mixer to produce the fiber aggregate in the system. By stirring the precursor liquid with a planetary mixer, the fibrous carbon molecules, which were individually isolated in the precursor liquid, gradually intertwine and form clumps, thereby producing a fibrous aggregate.

[0059] Here, the stirring conditions using the planetary mixer should be such that a fiber aggregate of the desired maximum diameter can be obtained. For example, the stirring conditions are preferably such that the temperature of the precursor liquid is between 25°C and 60°C, 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 in the planetary mixer, the greater the tendency to produce aggregates with a larger maximum diameter.

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

[0061] In this way, a mixed liquid containing dispersed rubber raw materials and fiber aggregates is obtained. By adding other components (such as additives) as needed to the resulting mixture, a rubber molded article forming composition for use in manufacturing rubber molded articles can be obtained. Alternatively, the resulting mixture may be diluted with an organic solvent to adjust the viscosity and other properties of the rubber molded article forming composition.

[0062] Subsequently, when manufacturing a rubber molded article using the rubber molded article forming composition, the rubber molded article of this disclosure can be obtained by adjusting the drying process of the rubber molded article forming composition. In the drying process, first, the rubber raw materials in the rubber molded article composition are reacted at a temperature lower than the vaporization temperature of the dispersion medium to form a rubber body in which the dispersion medium containing dispersed fiber aggregates is scattered inside. Then, the formed rubber body is heated to a temperature above the vaporization temperature of the dispersion medium to remove the dispersion medium, thereby forming a rubber foam, with fiber aggregates remaining within the foam cells of the rubber foam. As a result, a rubber molded article is obtained that includes the rubber foam and the fiber aggregates contained within the foam cells of the rubber foam.

[0063] <Fixing material> The fixing member of this disclosure has an elastic layer made of the rubber molded body of this disclosure as described above. Examples of fixing members in this disclosure include a roll-shaped member (fixing roll) and a belt-shaped member (fixing belt). The fixing member of this disclosure preferably comprises, in this order, a base material, an elastic layer made of a rubber molded body of this disclosure, and a surface layer. Since the fixing member of this disclosure has an elastic layer (the rubber molded body of this disclosure) that is low in hardness and has high thermal conductivity, it is expected that it will be able to conform well to the unevenness of the recording medium, improve fixing performance, shorten the heating time, reduce power consumption, increase the fixing speed, and further extend the lifespan.

[0064] The fixing member of this disclosure will be explained using a fixing belt as an example. Figure 1 is a schematic cross-sectional view showing an example of the fixing belt of this disclosure. The fixing belt 110 shown in Figure 1 comprises 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 configuration of the fixing belt 110 of this disclosure is not limited to the layer configuration shown in Figure 1, and may be a layer configuration in which an adhesive layer is interposed between the base layer 110A and the elastic layer 110B, a layer configuration in which an adhesive layer is interposed between the elastic layer 110B and the surface layer 110C, a layer configuration without the elastic layer 110B, a layer configuration without the surface layer 110C, or a layer configuration that combines these layer configurations.

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

[0066] [Base material layer] The base layer is preferably a layer containing 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, based on the total mass of the base layer.

[0067] [resin] The resin included in the base layer is preferably a heat-resistant resin. Examples of resins include high 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, and polyimideamide are also used. Among these, polyimide is preferred as the resin.

[0068] Examples of polyimides include imidized polyamic acid (a precursor of polyimide resin), which is a polymer of tetracarboxylic dianhydride and a diamine compound. Specifically, examples of polyimides include resins obtained by polymerizing equimolar amounts of tetracarboxylic dianhydride and a diamine compound in a solvent to obtain a solution of polyamic acid, and then imidizing that polyamic acid.

[0069] Examples of tetracarboxylic dianhydrides include both aromatic and aliphatic compounds, but from the viewpoint of heat resistance, aromatic compounds are preferred.

[0070] Examples of aromatic tetracarboxylic dianhydrides include pyromellitic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 3,3',4,4'-biphenylsulfone tetracarboxylic dianhydride, 1,4,5,8-naphthalene tetracarboxylic dianhydride, 2,3,6,7-naphthalene tetracarboxylic dianhydride, 3,3',4,4'-biphenyl ether tetracarboxylic dianhydride, 3,3',4,4'-dimethyldiphenylsilane tetracarboxylic dianhydride, 3,3',4,4'-tetraphenylsilane tetracarboxylic dianhydride, 1,2,3,4-furan tetracarboxylic dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenyl sulfide dianhydride, 4,4 Examples include '-bis(3,4-dicarboxyphenoxy)diphenylsulfone dianhydride, 4,4'-bis(3,4-dicarboxyphenoxy)diphenylpropane dianhydride, 3,3',4,4'-perfluoroisopropylidene diphthalic acid dianhydride, 3,3',4,4'-biphenyltetracarboxylic acid dianhydride, 2,3,3',4'-biphenyltetracarboxylic acid dianhydride, bis(phthalic acid)phenylphosphine oxide dianhydride, p-phenylene-bis(triphenylphthalic acid) dianhydride, m-phenylene-bis(triphenylphthalic acid) dianhydride, bis(triphenylphthalic acid)-4,4'-diphenyl ether dianhydride, and bis(triphenylphthalic acid)-4,4'-diphenylmethane dianhydride.

[0071] Examples of aliphatic tetracarboxylic dianhydrides include butanetetracarboxylic dianhydride, 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,3-dimethyl-1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclopentanetetracarboxylic dianhydride, 2,3,5-tricarboxycyclopentylacetic acid dianhydride, 3,5,6-tricarboxynorbonane-2-acetic acid dianhydride, 2,3,4,5-tetrahydrofurantetracarboxylic dianhydride, 5-(2,5-dioxotetrahydrofuryl)-3-methyl-3-cyclohexene-1,2-dicarboxylic acid dianhydride, and bicyclo[2,2,2]-octo-7-e Examples include aliphatic or alicyclic tetracarboxylic dianhydrides such as n-2,3,5,6-tetracarboxylic dianhydrides; and aliphatic tetracarboxylic dianhydrides having aromatic rings 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, aromatic tetracarboxylic dianhydrides are particularly good as tetracarboxylic dianhydrides. Specifically, for example, pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 3,3',4,4'-biphenylether tetracarboxylic dianhydride, and 3,3',4,4'-benzophenone tetracarboxylic dianhydride are good. Furthermore, pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, and 3,3',4,4'-benzophenone tetracarboxylic dianhydride are good, with 3,3',4,4'-biphenyltetracarboxylic dianhydride being particularly good.

[0073] Furthermore, tetracarboxylic dianhydrides may be used individually or in combination of two or more types. Furthermore, when using two or more tetracarboxylic dianhydrides in combination, aromatic tetracarboxylic dianhydrides or aliphatic tetracarboxylic dianhydrides may be used individually, or aromatic tetracarboxylic dianhydrides and aliphatic tetracarboxylic dianhydrides may be used in combination.

[0074] On the other hand, diamine compounds are diamine compounds that have two amino groups in their molecular structure. Diamine compounds can be either aromatic or aliphatic compounds, but aromatic compounds are preferred.

[0075] Examples of diamine compounds 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-trimethylindan, and 6-amino-1-(4'-aminophenyl)-1,3 ,3-trimethylindan, 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'-dimethyl Toxybiphenyl, 3,3'-dimethoxy-4,4'-diaminobiphenyl, 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 such as diaminotetraphenylthiophene having two amino groups bonded to an aromatic ring and heteroatoms other than the nitrogen atom of the amino groups;1,1-Metaxylylenediamine, 1,3-Propanediamine, Tetramethylenediamine, Pentamethylenediamine, Octamethylenediamine, Nonameethylenediamine, 4,4-Diaminoheptamethylenediamine, 1,4-Diaminocyclohexane, Isophoronediamine, Tetrahydrodicyclopentadienylenediamine, Hexahydro-4,7-Methanoindanidinemethylenediamine, Tricyclo[6,2,1,0; 2.7 Examples include aliphatic diamines such as ]-undecylendimethyldiamine and 4,4'-methylenebis(cyclohexylamine), as well as alicyclic diamines.

[0076] Among these, aromatic diamine compounds are particularly good as diamine compounds. Specifically, for example, p-phenylenediamine, m-phenylenediamine, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfide, and 4,4'-diaminodiphenyl sulfone are good, with 4,4'-diaminodiphenyl ether and p-phenylenediamine being particularly good.

[0077] Furthermore, the diamine compounds may be used individually or in combination of two or more. Furthermore, when using two or more diamine compounds in combination, aromatic diamine compounds or aliphatic diamine compounds may be used individually, or aromatic diamine compounds and aliphatic diamine compounds may be used in combination.

[0078] Among these, from the viewpoint of heat resistance, aromatic polyimides (specifically, imidides of polyamic acid (a precursor of polyimide resin), which is a polymer of aromatic tetracarboxylic dianhydride and aromatic diamine compounds) are preferred as polyimides. Furthermore, it is more preferable that the aromatic polyimide is a polyimide having a structural unit represented by the following general formula (PI1).

[0079] [ka]

[0080] In the general formula (PI1), R P1 R represents a phenyl group or a biphenyl group. P2 This indicates a divalent aromatic group. R P2 Examples of divalent aromatic groups include phenylene groups, naphthyl groups, biphenyl groups, and diphenyl ether groups. From the viewpoint of bending durability, phenylene groups and biphenyl groups are preferred as divalent aromatic groups.

[0081] The number-average molecular weight of polyimide is preferably 5,000 to 100,000, more preferably 7,000 to 50,000, and even more preferably 10,000 to 30,000.

[0082] The number-average molecular weight of polyimide is measured by gel permeation chromatography (GPC) under the following measurement conditions. • Column: Tosoh TSKgelα-M (7.8mm ID x 30cm) • Eluent: DMF (dimethylformamide) / 30 mM iBr / 60 mM phosphoric acid ·Flow rate: 0.6mL / min ·Injection volume: 60μL • Detector: RI (Differential Refractive Index Detector)

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

[0084] [Formation of the base layer] The base layer is obtained by preparing a coating solution for forming the base layer containing a resin and additives as needed, applying the obtained coating solution to a cylindrical base material, and drying it. In the case of polyimide resin, the base layer is obtained by preparing a coating solution for forming the base layer containing polyamic acid (a precursor of polyimide resin) and additives as needed, applying the obtained coating solution to a cylindrical or columnar support, and firing it (i.e., imidization).

[0085] [Elastic layer] The elastic layer is a layer made of the rubber molded body of this disclosure. The thickness (film thickness) of the elastic layer is preferably, for example, 30 μm or more and 600 μm or less, and more preferably 100 μm or more and 500 μm or less. The elastic layer can be formed by applying the rubber molded article manufacturing method described above.

[0086] [Surface layer] The surface layer is a layer that prevents the molten toner image from adhering to the surface (outer periphery) that comes into contact with the recording medium during the fixing process.

[0087] The surface layer requires, for example, heat resistance and release properties. From this viewpoint, it is preferable to use a heat-resistant release material for the material constituting the surface layer, and specific examples include fluororubber, fluororesin, silicone resin, polyimide resin, etc. Among these, fluororesin is a good choice as a heat-resistant release material. 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 vinyl fluoride (PVF).

[0088] The elastic layer side of the surface layer may be subjected to a surface treatment. The surface treatment may be a wet treatment or a dry treatment, and examples include liquid ammonia treatment, excimer laser treatment, plasma treatment, etc.

[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 can be formed by applying known methods, such as a coating method. Alternatively, a tubular surface layer may be prepared in advance and coated onto the outer circumference of the elastic layer to form the surface layer. Alternatively, an adhesive layer (for example, an adhesive layer containing a silane coupling agent with epoxy groups) may be formed on the inner surface of the tubular surface layer before coating its outer circumference.

[0091] The film thickness of the fixing belt is preferably, for example, 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 the fixing member of this disclosure has been described above using a fixing belt as an example, the fixing member of this disclosure may also be a fixing roll. When the fixing member of this disclosure is a fixing roll, it is preferable that the fixing roll has, for example, a cylindrical or columnar base material, an elastic layer made of the rubber molded body of this disclosure, and a surface layer (also called a release layer) in this order.

[0093] [Applications of fixing members] The fixing member of this disclosure is applicable to both heated belts and pressurized belts if they are fixing belts. Furthermore, the fixing member of this disclosure is applicable to both heated rolls and pressurized rolls if they are fixing rolls. 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 applying the fixing belt to a heating belt that heats by electromagnetic induction, it is preferable to provide a metal layer (heating layer) that generates heat by electromagnetic induction between the base material layer and the elastic layer.

[0094] <Fusing device> The fixing device of this disclosure can have various configurations. For example, one example is a fixing device comprising a first rotating body and a second rotating body positioned in contact with the outer surface of the first rotating body, wherein a recording medium on which a toner image is formed on its surface is inserted into the contact portion between the first rotating body and the second rotating body to fix the toner image. The fixing member of this disclosure is applied as at least one of the first rotating body and the second rotating body.

[0095] Below, the fixing apparatus of the present disclosure will be described as follows: as a first embodiment, a fixing apparatus comprising a heating roll and a pressure belt; as a second embodiment, a fixing apparatus comprising a heating belt and a heating roll; and as a third embodiment, an electromagnetic induction heating type fixing apparatus comprising a heating belt and a heating roll. 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. Furthermore, the fixing device of this disclosure is not limited to the first to third embodiments, and may be a fixing device comprising a heating roll or heating belt and a pressure belt. The fixing member of this disclosure can be applied to either the heating belt or the pressure belt.

[0096] (First embodiment of the fixing device) A first embodiment of the fixing device will be described with reference to Figure 2. Figure 2 is a schematic diagram showing an example of the first embodiment of the fixing device (i.e., fixing device 60).

[0097] As shown in Figure 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 pressing member) that presses the heating roll 61 via the pressure belt 62. The pressure pad 64 only needs to be relatively pressurized, for example, between the pressure belt 62 and the heating roll 61. Therefore, the pressure belt 62 side may be pressurized against the heating roll 61, or the heating roll 61 side may be pressurized against the heating roll 61.

[0098] A halogen lamp 66 (an example of a heating means) is installed inside the heating roll 61. The heating means is not limited to a halogen lamp; other heat-generating components may be used.

[0099] Meanwhile, a temperature-sensing element 69 is positioned in contact with the surface of the heating roll 61. Based on the temperature measured by this temperature-sensing element 69, the illumination of the halogen lamp 66 is controlled to maintain the surface temperature of the heating roll 61 at a target set temperature (e.g., 150°C).

[0100] The pressure belt 62 is rotatably supported, for example, by an internally positioned pressure pad 64 and a belt travel guide 63. In the clamping region N (nip portion), it is pressed against the heating roll 61 by the pressure pad 64.

[0101] The pressure pad 64 is positioned, for example, inside the pressure belt 62, and is pressed against the heating roll 61 via the pressure belt 62, forming a clamping area N between it and the heating roll 61. The pressing pad 64 includes, for example, a front clamping member 64a positioned on the entrance side of the clamping area N to secure a wide clamping area N, and a peeling clamping member 64b positioned on the exit side of the clamping area N to impart distortion to the heating roll 61.

[0102] To reduce the sliding resistance between the inner circumferential 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 are in contact with the pressure belt 62. The pressure pad 64 and the sliding member 68 are held together by a metal retaining member 65. The sliding member 68 is provided, for example, so that its sliding surface contacts the inner circumferential surface of the pressure belt 62, and is involved in retaining and supplying the oil present between it and the pressure belt 62.

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

[0104] The heating roll 61 rotates in the direction of arrow S by, for example, a drive motor (not shown), and the pressure belt 62 rotates in the direction of arrow R, opposite to the direction of rotation of the heating roll 61, in accordance with this rotation. That is, for example, while the heating roll 61 rotates clockwise in Figure 2, the pressure belt 62 rotates counterclockwise.

[0105] Then, the paper K (an example of a recording medium) having an unfixed toner image is guided, for example, by a fuser entrance guide 56 and transported to the sandwiching area N. As the paper K passes through the sandwiching area N, the unfixed toner image on the paper K is fixed by the pressure and heat acting on the sandwiching area N.

[0106] In the fixing device 60, for example, a concave front clamping member 64a that conforms to the outer surface of the heating roll 61 ensures a wider clamping area N compared to a configuration without the front clamping member 64a.

[0107] Furthermore, the fixing device 60 is configured such that, for example, the peeling and clamping member 64b is positioned to protrude from the outer surface of the heating roll 61, thereby increasing the localized distortion of the heating roll 61 in the exit region of the clamping region N.

[0108] By arranging the peeling and clamping member 64b in this manner, for example, when the fixed paper K passes through the peeling and clamping region, it will pass through a locally large amount of strain, 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 provided downstream of the clamping area N of the heating roll 61. The peeling member 70 is held by a holding member 72 in a position where the peeling claws 71 are in close proximity to the heating roll 61 in a direction opposite to the rotation direction of the heating roll 61 (counter direction).

[0110] (Second embodiment of the fixing device) A second embodiment of the fixing device will be described with reference to Figure 3. Figure 3 is a schematic diagram showing an example of the second embodiment of the fixing device (i.e., fixing device 80).

[0111] As shown in Figure 3, the fixing device 80 is configured to include, 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) pressed against the heating belt 84 (fixing belt module 86). For example, a pinching region N (nip portion) is formed at the contact point between the heating belt 84 (fixing belt module 86) and the pressure roll 88. In the pinching region N, the paper K (an example of a recording medium) is pressurized and heated to fix the toner image.

[0112] The fixing belt module 86 includes, for example, an endless heating belt 84, a heating and pressing roll 89 around which the heating belt 84 is wrapped on the pressure roll 88 side and which is rotationally driven by the rotational force of a motor (not shown) and presses the heating belt 84 toward the pressure roll 88 side from its inner circumferential surface, and a support roll 90 which supports the heating belt 84 from the inside at a position different from the heating and pressing roll 89. The fixing belt module 86 includes, for example, a support roll 92 positioned outside the heating belt 84 to define its circumferential path, a posture correction roll 94 that corrects the posture of the heating belt 84 from the heating pressure roll 89 to the support roll 90, and a support roll 98 that applies tension to the heating belt 84 from its inner circumferential surface downstream of the clamping region N formed by the heating belt 84 and the pressure roll 88.

[0113] The fixing belt module 86 is provided such that, for example, 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 is in contact with the inner circumferential surface of the heating belt 84, and is involved in holding and supplying the oil present between it and the heating belt 84. Here, the sliding member 82 is provided such that both ends are supported by the support member 96.

[0114] Inside the heated pressing 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) installed inside to heat the heating belt 84 from the inner circumferential side. At both ends of the support roll 90, for example, spring members (not shown) are provided to press the heating belt 84 outwards.

[0116] The support roll 92 is, for example, a cylindrical roll made of aluminum, and a release layer made of fluororesin with a thickness of 20 μm is formed on the surface of the support roll 92. The release layer on the support roll 92 is formed, for example, to prevent toner or paper dust from the outer 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 provided to heat the heating belt 84 from the outer circumferential side.

[0117] In other words, for example, the heating belt 84 is heated by the heating and pressing roll 89, the support roll 90, and the support roll 92.

[0118] The posture correction roll 94 is, for example, a cylindrical roll made of aluminum, and an end position measuring mechanism (not shown) for measuring the end position of the heating belt 84 is located near the posture correction roll 94. The posture correction roll 94 is equipped with, for example, an axial displacement mechanism (not shown) that displaces the contact position of the heating belt 84 in the axial direction according to the measurement results of the end position measuring 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, rotatably supported and pressed against the portion of the heating belt 84 that 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 in the direction of arrow S, the pressure roll 88 rotates in the direction of arrow R, following the heating belt 84 (heating pressure roll 89).

[0120] The paper K, which has an unfixed toner image (not shown), is then transported in the direction of arrow P and guided to the clamping area N of the fixing device 80. As the paper K passes through the clamping area N, the unfixed toner image on the paper K is fixed by the pressure and heat acting on the clamping area N.

[0121] In the fixing device 80, a halogen heater (halogen lamp) was described as one example of a heating means, but the device is not limited to this. Other heating elements such as radiant lamps (heating elements that emit radiation (infrared rays, etc.)) and resistive heating elements (heating elements that generate Joule heat by passing an electric current through a resistor: for example, those made by forming a resistive film on a ceramic substrate and firing it) may also be used.

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

[0123] The fixing device 200 is an electromagnetic induction type fixing device equipped with a belt 220 having a metal layer. In the fixing device 200, the belt 220 is used as the fixing belt of this disclosure. As shown in Figure 4, a pressure roll (pressure member) 211 is positioned to apply pressure to a portion of the belt 220, and a contact area (nip) is formed between the belt 220 and the pressure roll 211 for efficient fixing, and the belt 220 is curved to conform to the circumferential surface of the pressure roll 211. Furthermore, a bent portion is formed at the end of the contact area (nip) where the belt bends, in order to ensure the release of the recording medium.

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

[0125] Inside the belt 220, an opposing member 213 is positioned opposite the pressure roll 211. The opposing member 213 is made of metal, heat-resistant resin, heat-resistant rubber, etc., and has a pad 213B that contacts 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, which incorporates an electromagnetic induction coil (excitation coil) 212a, is provided at a position opposite the pressure roll 211 (an example of a pressure member) with respect to the belt 220. The electromagnetic induction heating device 212 changes the magnetic field generated by applying an alternating current to the electromagnetic induction coil in an excitation circuit, thereby generating eddy currents in a metal layer (not shown) of the belt 220 (for example, an electromagnetic induction metal layer). These eddy currents are converted into heat (Joule heat) by the electrical resistance of the metal layer (not shown), resulting in the surface of the belt 220 heating up. The position of the electromagnetic induction heating device 212 is not limited to the position shown in Figure 4. For example, it may be installed upstream of the contact area of ​​the belt 220 in the rotation direction B, or it may be installed inside the belt 220.

[0127] In the fixing device 200, a driving force is transmitted by a drive device to a gear fixed to the end of the belt 220, causing the belt 220 to rotate on its own 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 in the direction of arrow A through the contact area (nip) between the belt 220 and the pressure roll 211 in the fixing device 200, and the unfixed toner image 214 is fixed to the recording medium 215 by pressure applied while in a molten state.

[0128] <Image forming apparatus> Next, the image forming apparatus of this disclosure will be described. The image forming apparatus disclosed herein comprises an image holder, a charging means for charging the surface of the image holder, an electrostatic latent image forming means for forming an electrostatic latent image on the charged surface of the image holder, a developing means for developing the electrostatic latent image formed on the surface of the image holder 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. Furthermore, the fixing device of this disclosure is applied as the fixing means.

[0129] In this disclosure, the fixing device may be made into a cartridge that can be attached to and detached from the image forming apparatus. In other words, the image forming apparatus of this disclosure may include the fixing device of this disclosure as a component of the process cartridge.

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

[0131] As shown in Figure 5, the image forming apparatus 100 of the present disclosure is, for example, an intermediate transfer type image forming apparatus generally called a tandem type, and comprises a plurality of image forming units 1Y, 1M, 1C, and 1K in which toner images of each color component are formed by an electrophotographic method; 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 transfers (secondary transfer) the superimposed toner images transferred onto the intermediate transfer belt 15 onto a recording medium, paper K; and a fixing device 60 that fixes the secondary transferred image onto the paper K. The image forming apparatus 100 also has a control unit 40 that controls the operation of each device (each part).

[0132] This fixing device 60 is the first embodiment of the fixing device described above. The image forming apparatus 100 may also be configured to include the second embodiment of the fixing device described above.

[0133] Each image forming unit 1Y, 1M, 1C, and 1K of the image forming apparatus 100 is equipped with a photoreceptor 11 that rotates in the direction of arrow A, as an example of an image holder that holds the toner image formed on its surface.

[0134] Around the photoreceptor 11, a charger 12 is provided as an example of a charging means for charging the photoreceptor 11, and a laser exposure unit 13 (indicated by the symbol Bm in the figure) is provided as an example of a latent image forming means for writing an electrostatic latent image onto the photoreceptor 11.

[0135] Furthermore, surrounding the photoreceptor 11, as an example of a developing means, is a developer 14 which contains toners for each color component and visualizes the electrostatic latent image on the photoreceptor 11 using the toner, and a primary transfer roll 16 which transfers the toner images for each color component formed on the photoreceptor 11 to an intermediate transfer belt 15 in a primary transfer unit 10.

[0136] Furthermore, a photoreceptor cleaner 17 is provided around the photoreceptor 11 to remove any residual toner on the photoreceptor 11, and the electrophotographic devices, including the charger 12, laser exposure unit 13, developer unit 14, primary transfer roll 16, and photoreceptor cleaner 17, are sequentially arranged along the rotational direction of the photoreceptor 11. These image forming units 1Y, 1M, 1C, and 1K are arranged in a substantially straight line 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 material, is a film-like pressure belt with a resin such as polyimide or polyamide as the base layer and containing an appropriate amount of an antistatic agent such as carbon black. Its volume resistivity is 10 6 Ωcm or more 10 14 It is formed to be less than or equal to Ωcm, and its thickness is, for example, about 0.1 mm.

[0138] The intermediate transfer belt 15 is driven (rotated) in a circulating manner in direction B shown in Figure 5 at a speed appropriate for the purpose by various rolls. These various rolls include a drive roll 31 that rotates the intermediate transfer belt 15 by a motor (not shown) with excellent constant-speed performance, a support roll 32 that supports the intermediate transfer belt 15 which extends substantially linearly along the arrangement direction of each photoreceptor 11, a tension-applying roll 33 that applies tension to the intermediate transfer belt 15 and functions as a corrective roll to prevent the intermediate transfer belt 15 from meandering, a back roll 25 provided in the secondary transfer section 20, and a cleaning back roll 34 provided in the cleaning section that scrapes off residual toner on the intermediate transfer belt 15.

[0139] The primary transfer section 10 consists of a primary transfer roll 16 positioned opposite the photoreceptor 11, with an intermediate transfer belt 15 in between. The primary transfer roll 16 consists of a core and a sponge layer, which is an elastic layer fixed around the core. The core is a cylindrical rod made of metal such as iron or stainless steel. The sponge layer is made of a blend of NBR, SBR, and EPDM rubber containing a conductive agent such as carbon black, and has a volume resistivity of 10 7.510 or more Ωcm 8.5 It is a sponge-like cylindrical roll with a resistance of 10 Ωcm or less.

[0140] The primary transfer roll 16 is disposed in pressure contact with the photoreceptor 11 with the intermediate transfer belt 15 interposed therebetween, and a voltage (primary transfer bias) having a polarity opposite to the charging polarity of the toner (negative polarity; the same applies hereinafter) is applied to the primary transfer roll 16. Thus, the toner images on the respective photoreceptors 11 are sequentially electrostatically attracted to the intermediate transfer belt 15, and a superimposed toner image is formed on the intermediate transfer belt 15.

[0141] The secondary transfer unit 20 includes a back roll 25 and a secondary transfer roll 22 disposed on the toner image holding surface side of the intermediate transfer belt 15.

[0142] The back roll 25 is composed of a tube of a blend rubber of EPDM and NBR in which carbon is dispersed on the surface and EPDM rubber inside. The surface resistivity thereof is formed to be 10 Ω / □ or more and 10 Ω / □ or less, and 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 surface side of the intermediate transfer belt 15 to form a counter electrode for the secondary transfer roll 22, and a metal power supply roll 26 to which a secondary transfer bias is stably applied is disposed in contact therewith. 7 10 or more Ω / □ 10 The secondary transfer roll 22 is composed of a core and a sponge layer as an elastic layer fixed around the core. The core is a cylindrical rod made of a metal such as iron or SUS. The sponge layer is formed of a blend rubber of NBR, SBR, and EPDM containing a conductive agent such as carbon black, and is a sponge-like cylindrical roll having a volume resistivity of 10 Ωcm or more and 10 Ωcm or less.

[0143] On the other hand, the secondary transfer roll 22 is composed of a core and a sponge layer as an elastic layer fixed around the core. The core is a cylindrical rod made of a metal such as iron or SUS. The sponge layer is formed of a blend rubber of NBR, SBR, and EPDM containing a conductive agent such as carbon black, and is a sponge-like cylindrical roll having a volume resistivity of 10 Ωcm or more and 10 Ωcm or less. 7.5 10 or more Ωcm 8.5 It is a sponge-like cylindrical roll with a resistance of 10 Ωcm or less.

[0144] The secondary transfer roll 22 is then pressed against the back roll 25 with the intermediate transfer belt 15 in between, and the secondary transfer roll 22 is grounded to form a secondary transfer bias between itself and the back roll 25, thereby secondary transferring the toner image onto the paper K that is transported to the secondary transfer section 20.

[0145] Furthermore, an intermediate transfer belt cleaner 35 is provided downstream of the secondary transfer section 20 of the intermediate transfer belt 15, which removes residual toner and paper dust from the intermediate transfer belt 15 after secondary transfer and cleans the surface of the intermediate transfer belt 15. The cleaner is positioned to be able to move toward and away from 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) are examples of transfer means.

[0147] Meanwhile, upstream of the yellow image forming unit 1Y, a reference sensor (home position sensor) 42 is provided that generates a reference signal, which serves as a reference for determining the image forming timing in each image forming unit 1Y, 1M, 1C, and 1K. This reference sensor 42 recognizes a mark provided on the back side of the intermediate transfer belt 15 and generates a reference signal. Based on the recognition of this reference signal, each image forming unit 1Y, 1M, 1C, and 1K is configured to start image forming according to instructions from the control unit 40. Furthermore, an image density sensor 43 for image quality adjustment is located downstream of the black image forming unit 1K.

[0148] Furthermore, the image forming apparatus of this disclosure includes, as a means for transporting paper K, a paper storage section 50 for storing paper K, a paper feed roll 51 for taking out and transporting the paper K accumulated in the paper storage section 50 at a predetermined timing, a transport roll 52 for transporting the paper K fed out by the paper feed roll 51, a transport guide 53 for sending the paper K transported by the transport roll 52 to the secondary transfer section 20, a transport belt 55 for transporting the paper K that has been secondarily transferred by the secondary transfer roll 22 to the fixing device 60, and a fixing inlet guide 56 for guiding the paper K to the fixing device 60.

[0149] Next, the basic image-forming process of the image-forming apparatus disclosed herein will be described. In the image forming apparatus disclosed herein, image data output from an image reading device (not shown) or a personal computer (PC) (not shown) is processed 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 applies various image processing steps to the input reflectance data, including shading correction, positional shift correction, brightness / color space conversion, gamma correction, frame removal, color editing, and movement editing. The processed image data is converted into four-color chromatic data (Y, M, C, K) and output to the laser exposure unit 13.

[0151] In the laser exposure unit 13, according to the input color tone data, an exposure beam Bm emitted from, for example, a semiconductor laser is irradiated onto each of the photoreceptors 11 of the image forming units 1Y, 1M, 1C, and 1K. After the surface of each photoreceptor 11 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 unit 13, and an electrostatic latent image is formed. The formed electrostatic latent image is then developed as toner images of the respective colors Y, M, C, and K by the respective image forming units 1Y, 1M, 1C, and 1K.

[0152] The toner images formed on the photoreceptors 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 photoreceptor 11 comes into contact with the intermediate transfer belt 15. More specifically, in the primary transfer section 10, a primary transfer roll 16 applies a voltage (primary transfer bias) with the opposite polarity to the toner's charge polarity (negative polarity) to the substrate of the intermediate transfer belt 15, and the toner images are sequentially superimposed on the surface of the intermediate transfer belt 15 to perform primary transfer.

[0153] After the toner image is sequentially transferred to the surface of the intermediate transfer belt 15, the intermediate transfer belt 15 moves and the toner image is transported to the secondary transfer section 20. When the toner image is transported to the secondary transfer section 20, the transport mechanism rotates the paper feed roll 51 in time with the transport of the toner image to the secondary transfer section 20, and paper K of the desired size is supplied from the paper storage section 50. The paper K supplied by the paper feed roll 51 is transported by the transport roll 52 and reaches the secondary transfer section 20 via the transport guide 53. Before reaching the secondary transfer section 20, the paper K is temporarily stopped, and the position of the paper K and the position of the toner image are aligned by rotating the alignment roll (not shown) in time with the movement of the intermediate transfer belt 15 holding the toner image.

[0154] In the secondary transfer section 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 transported in sync with the timing, is sandwiched between the intermediate transfer belt 15 and the secondary transfer roll 22. When a voltage (secondary transfer bias) with 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 image held on the intermediate transfer belt 15 is electrostatically transferred all at once onto the paper K in the secondary transfer section 20, which is pressed by the secondary transfer roll 22 and the back roll 25.

[0155] Subsequently, the paper K on which the toner image has been electrostatically transferred is peeled off the intermediate transfer belt 15 by the secondary transfer roll 22 and transported to the transport belt 55 located downstream of the secondary transfer roll 22 in the paper transport direction. The transport belt 55 transports the paper K to the fuser 60 at an optimal transport speed for the fuser 60. The unfixed toner image on the paper K transported to the fuser 60 is fixed to the paper K by the fuser 60 through a fixing process using heat and pressure. The paper K with the fixed image then transported to the paper discharge and storage section (not shown) located in the discharge section of the image forming apparatus.

[0156] Meanwhile, after the transfer to paper K is completed, any 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 this embodiment has been described above, it is not intended to be interpreted as being limited to the above embodiment, and various modifications, changes, and improvements are possible. [Examples]

[0158] The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the following examples.

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

[0160] (Formation of an elastic layer) 65 parts by mass of water and 30 parts by mass of carbon nanotubes (manufactured by Showa Denko K.K.) were mixed, and 5 parts by mass of an emulsifier (a mixture of polyoxyethylene dilaurate and polyoxyethylene dioleate (manufactured by Takemoto Oil & Fat Co., Ltd.) in a mass ratio of 1:3) was added to prepare a dispersion. The obtained dispersion was subjected to high-pressure dispersion treatment using a high-pressure homogenizer (HC3, manufactured by Sanmaru Machinery Industry Co., Ltd.) (conditions: liquid temperature 45°C, 50 MPa, 3 cycles (i.e., 3 valve passes)). Next, 50 parts by mass of silicone rubber stock (X34-1053, manufactured by Shin-Etsu Chemical Co., Ltd.) were added to 50 parts by mass of the dispersion after high-pressure dispersion treatment to prepare a precursor solution. The obtained precursor solution was stirred in a planetary mixer (ACM-5LVT, manufactured by Aikousha Seisakusho Co., Ltd.) under the following conditions: liquid temperature 25°C, under vacuum, for 10 minutes. Based on the above, we obtained a coating liquid for forming an elastic layer (composition for forming a rubber molded article) containing 33% by mass of aggregates (i.e., fiber aggregates) in which multiple carbon nanotubes are intertwined with each other in the solid content. Next, the obtained elastic layer-forming coating solution was applied to the substrate layer to form a coating film, and this 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 consisted of a rubber molded body containing rubber foam and fiber aggregates enclosed within the foam cells of the rubber foam.

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

[0162] The fixing belt was obtained through the above process.

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

[0164] <Examples 4-6> The fixing belts of Examples 4 to 6 were obtained in the same manner as in Example 1, except that the method for forming the elastic layer in Example 1 was changed as shown below. In other words, 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 elastic layer forming solution onto the substrate layer to form the coating film was changed to 120 minutes (Example 4), 15 minutes (Example 5), or 10 minutes (Example 6), respectively.

[0165] <Examples 7-10> The fixing belts of Examples 7 to 10 were obtained in the same manner as in Example 1, except that the method for forming the elastic layer in Example 1 was changed as shown below. In other words, the elastic layer was formed in the same manner as in Example 1, except that the stirring time of the dispersion and the temperature at which the coating film was heated after applying the elastic layer forming solution to the substrate layer were changed as follows. Example 7: Stirring time 20 minutes, heating temperature 100℃ Example 8: Stirring time 5 minutes, heating temperature 140℃ Example 9: Stirring time 40 minutes, heating temperature 105℃ Example 10: Stirring time 3 minutes, heating temperature 140℃

[0166] <Examples 11-13> The fixing belts of Examples 11 to 13 were obtained in the same manner as in Example 1, except that the method for forming the elastic layer in Example 1 was changed as shown below. Specifically, the elastic layer was formed in the same manner as in Example 1, except that 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) in the formation of the elastic layer in Example 1.

[0167] <Examples 14, 15> The fixing belts of Examples 14 and 15 were obtained in the same manner as in Example 1, except that the method for forming the elastic layer in Example 1 was changed as shown below. Specifically, the elastic layer was formed in the same manner as in Example 1, except that the amount of carbon nanotubes used when preparing the dispersion was changed to 15 parts by mass (Example 14) or 50 parts by mass (Example 15) in the formation of the elastic layer in Example 1.

[0168] <Example 16> An anchoring belt of Example 16 was obtained in the same manner as in Example 1, except that the method for forming the elastic layer in Example 1 was changed as shown below.

[0169] (Formation of an elastic layer) -Manufacturing of spheroidal graphene- A graphene film was generated and deposited in a mold with a particle size of 20 μm using CaCO3 (Shiraishi Kogyo Co., Ltd.) with a CVD apparatus (Ishikawa Sangyo Co., Ltd.). After that, the mold was removed by washing with hydrochloric acid to obtain spherical graphene. -Film formation- A dispersion was prepared by dispersing 30 parts by mass of the above-mentioned spherical graphene in 70 parts by mass of water. To 50 parts by mass of this dispersion, 50 parts by mass of silicone rubber stock solution (X34-1053, manufactured by Shin-Etsu Chemical Co., Ltd.) was added to obtain a coating solution for forming an elastic layer (composition for forming a rubber molded article). An elastic layer was formed in the same manner as in Example 1, except that the obtained coating solution for forming an elastic layer was used.

[0170] <Comparative Example 1> A fixing belt for Comparative Example 1 was obtained in the same manner as in Example 1, except that the method for forming the elastic layer in Example 1 was changed as shown below. In other words, the elastic layer was formed in the same manner as in Example 1, except that the silicone rubber stock solution (X34-1053, manufactured by Shin-Etsu Chemical Co., Ltd.) was used directly as the coating solution for forming the elastic layer.

[0171] <Comparative Example 2> A fixing belt for Comparative Example 2 was obtained in the same manner as in Example 1, except that the method for forming the elastic layer in Example 1 was changed as shown below. Specifically, an elastic layer was formed in the same manner as in Example 1, except that instead of using the dispersion used in Example 1, a coating solution for forming an elastic layer was used, which was obtained by adding azobisisobutyronitrile, a foaming agent, to a silicone rubber stock solution (X34-1053, manufactured by Shin-Etsu Chemical Co., Ltd.).

[0172] <Comparative Example 3> A fixing belt for Comparative Example 3 was obtained in the same manner as in Example 1, except that the method for forming the elastic layer in Example 1 was changed as shown below. 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 replaced with 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 and 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 brought into pressure contact with 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 passing 450,000 sheets of A4 paper. 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 set to 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 in the anchoring belt. B: There is a slight offset (between 1 and 3 locations) in the anchoring belt. C: An offset is observed in some parts of the anchoring belt (between 4 and 7 locations).

[0177] [Table 1]

[0178] From the above results, it can be seen that the fixing belt of this embodiment has higher thermal conductivity and superior bending durability compared to the fixing belt of the comparative example. Furthermore, it can be seen that the fixing belt of this embodiment also has superior compression durability and paper surface conformability. [Explanation of Symbols]

[0179] 60 Fixing device 62 Compression belt 63 Belt Drive Guide 64 Pressure Pads 64a Front clamping member 64b Peeling and clamping member 65 Retaining member 66 Halogen lamps 68 Sliding member 69 Temperature sensing element 70 Release Member 71. Detachable nails 72 Retaining member 80 Fixing device 82 Sliding member 84. Heated belt 86 Fixing belt module 88 Pressure Roll 89A Halogen Heater 89. Heated pressing roll 90A halogen heater 90 support rolls 92A Halogen Heater 92 Support Roll 94 Posture Correction Roll 96 Support member 98 Support Roll 100 Image forming apparatus 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 roll-shaped or belt-shaped fixing member having a base material, an elastic layer, and a surface layer in this order, The elastic layer is composed of a rubber molded body comprising a rubber foam and granular hollow aggregates of carbon material enclosed within the foam cells of the rubber foam, A fixing member used to fix a toner image formed on the surface of a recording medium onto the recording medium.

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

3. The fixing member according to claim 2, wherein the diameter X of the foam cell is more than 1.0 times and 50 times or less the maximum diameter Y of the granular hollow aggregate of carbon material.

4. The fixing member according to any one of claims 1 to 3, wherein the cell density of the rubber foam is less than 100%.

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

6. The fixing member according to any one of claims 1 to 5, wherein the occupancy rate of the granular hollow aggregate of carbon material in the foam cell is greater than 0% and less than 100%.

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

8. The fixing member according to any one of claims 1 to 7, wherein the granular hollow aggregate of the carbon material is a granular hollow aggregate formed by a plurality of fibrous carbons intertwined with each other.

9. A fixing member according to any one of claims 1 to 8, wherein the thermal conductivity is 1.0 W / m·K or more and 100 W / m·K or less, and the AskerC hardness is 10 or more and 60 or less.

10. It comprises a first rotating body and a second rotating body positioned in contact with the 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 for fixing a toner image by inserting a recording medium on which a toner image has been formed on its surface into the contact area between the first rotating body and the second rotating body.

11. A first rotating body and a second rotating body disposed in contact with the outer surface of the first rotating body, At least one of the first rotating body and the second rotating body is a fixing member having an elastic layer made of a rubber molded body containing a rubber foam and granular hollow aggregates of carbon material enclosed within the foam cells of the rubber foam. A fixing device for fixing a toner image by inserting a recording medium on which a toner image has been formed on its surface into the contact area between the first rotating body and the second rotating body.

12. Image holder and, A charging means for charging the surface of the image holder, An electrostatic latent image forming means for forming an electrostatic latent image on the charged surface of the image holder, A developing means that develops an electrostatic latent image formed on the surface of the image holder with a developer containing toner to form a toner image, A transfer means for transferring the toner image onto the surface of a recording medium, Fixing means comprising a fixing device according to claim 10 or claim 11 for fixing the toner image onto the recording medium, An image forming apparatus equipped with the following features.

Images