Slide member, fixing device, and image forming apparatus

Abstract

To provide a slide member that is excellent in maintainability of slide resistance.SOLUTION: A slide surface includes heat-resistant thermoplastic resin other than fluororesin, and resin particles having a siloxane group other than the heat-resistant thermoplastic resin. The average particle diameter of the resin particles is 0.1 μm or more and 10 μm or less. The surface roughness Rsk of the slide surface is 1.0 or less. The surface exposure ratio of the resin particles on the slide surface is 2% or more.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] For example, Patent Document 1 discloses an image fixing device comprising: "a heat fixing roll arranged to be rotatable; an endless belt arranged to be able to run while in contact with the heat fixing roll; and a pressure pad arranged inside the endless belt and pressing the heat fixing roll via the endless belt so that a nip portion is formed between the endless belt and the heat fixing roll through which a recording sheet carrying an unfixed toner image can pass, the image fixing device being characterized in that modified silicone oil is interposed between the pressure pad and the endless belt as a lubricant."

[0003] The patent document also states that "an image fixing device in which a pressing member disposed inside a tubular film body presses the tubular film body against a heating drive roll to form a nip portion on the outer surface of the tubular film body through which a recording material passes, and a fluororesin is disposed on the sliding contact surface of the pressing member, and a lubricant is interposed between the pressing member and the inner surface of the tubular film body, thereby allowing the tubular film body to run. An image fixing device characterized in that a lipophilic fluororesin is used on the sliding contact surface of the pressing member, or a lipophilic agent is used in combination with the fluororesin."

[0004] In addition, Patent Document 3 describes a low-friction member in which a first fluororesin powder having a median diameter in the range of 10 μm to 100 μm and a second fluororesin powder having a median diameter in the range of 0.1 μm to 5 μm are dispersed in a polyimide resin, the surface roughness Rsk being 0.500 or more and the surface exposure rate of the fluororesin being 15.0% or more. "Low friction member." [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 10-213984 [Patent Document 2] JP 2001-249558 A [Patent Document 2] Patent No. 6142385 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a sliding member which is superior in maintaining sliding resistance compared to a sliding member whose sliding surface is constituted by a glass cloth and a fluororesin impregnated into the glass cloth. [Means for solving the problem]

[0007] Specific means for solving the above problems include the following aspects. <1> The sliding surface is configured to include a heat-resistant thermoplastic resin other than a fluororesin, and resin particles having a siloxane group other than the heat-resistant thermoplastic resin, The resin particles have an average particle size of 0.1 μm or more and 10 μm or less, The surface roughness Rsk of the sliding surface is 1.0 or less, the surface exposure rate of the resin particles on the sliding surface is 2% or more; Sliding member. <2> The average particle size of the resin particles is 0.5 μm or more and 4 μm or less. <1> The sliding member according to claim 1. <3> The surface roughness Rsk of the sliding surface is 0.6 or less. <1> or <2> The sliding member according to claim 1. <4> The surface exposure rate of the resin particles on the sliding surface is 3% or more. <1> ~ <3> 13. The sliding member according to claim 12 . <5> The heat-resistant thermoplastic resin is at least one resin selected from the group consisting of polyether ether ketone resin, polyphenylene sulfide resin, polyetherimide resin, and polyphenylsulfone resin. <1> ~ <4> 13. The sliding member according to claim 12 . <6> The heat-resistant thermoplastic resin is at least one resin selected from the group consisting of polyether ether ketone resin and polyphenylene sulfide resin. <1> ~ <5> 13. The sliding member according to claim 12 . <7> The resin particles are thermosetting silicone resin particles. <1> ~ <6> 13. The sliding member according to claim 12 . <8> The thermosetting silicone resin particles are modified thermosetting silicone resin particles. <7> The sliding member according to claim 1. <9> The content of the resin particles is 1.0% by mass or more and 20.0% by mass or less with respect to the heat-resistant thermoplastic resin. <1> ~ <8> 13. The sliding member according to claim 12 . <10> The content of the resin particles is 3% by mass or more and 25% by mass or less with respect to the heat-resistant thermoplastic resin. <9> The sliding member according to claim 1. <11> The resin particles have an average particle size of 0.5 μm or more and 4 μm or less, The surface roughness Rsk of the sliding surface is 0.6 or less, The surface exposure rate of the resin particles on the sliding surface is 3% or more. <1> ~ <10> 13. The sliding member according to claim 12 . <12> the heat-resistant thermoplastic resin is at least one resin selected from the group consisting of polyether ether ketone resin, polyphenylene sulfide resin, polyetherimide resin, and polyphenylsulfone resin; The content of the resin particles is 1.0% by mass or more and 20.0% by mass or less with respect to the heat-resistant thermoplastic resin, The resin particles are thermosetting silicone resin particles. <1> ~ <11> 13. The sliding member according to claim 12 . <13> A first rotating body; a second rotor disposed in contact with the first rotor; a pressing member disposed on an inner circumferential surface of the second rotating body and pressing the second rotating body against the first rotating body from the inner circumferential surface of the second rotating body; Between the inner circumferential surface of the second rotating body and the pressing member, <1> ~ <12> The sliding member according to any one of the above items, a lubricant interposed between an inner circumferential surface of the second rotor and the sliding member; A fixing device comprising: <14> The inner circumferential surface of the second rotor is made of a resin having at least one group selected from the group consisting of an amide group, an imide group, a ketone group, and a sulfide group. <13> The fixing device according to claim 1 . <15> The lubricant contains an oil having a siloxane group as a main chain. <13> or <14> The fixing device according to claim 1 . <16> An image carrier; a latent image forming device for forming a latent image on a surface of an image carrier; a developing device for developing the latent image into a toner image using a developer; a transfer device for transferring the developed toner image onto a recording medium; Fixing the toner image on the recording medium; <13> ~ <15> 13. The fixing device according to claim 12, An image forming apparatus comprising: Effect of the Invention

[0008] <1> According to the present invention, it is possible to provide a sliding member having excellent maintenance of sliding resistance compared to a sliding member having a sliding surface including glass cloth and a fluororesin impregnated into the glass cloth.

[0009] <2> According to the present invention, it is possible to provide a sliding member that is excellent in maintaining sliding resistance, as compared with a case in which the average particle size of the resin particles is less than 0.5 μm or exceeds 4 μm. <3> According to the present invention, it is possible to provide a sliding member which is excellent in maintaining sliding resistance, as compared with a sliding surface having a surface roughness Rsk of more than 0.6. <4> According to the present invention, it is possible to provide a sliding member having excellent maintenance of sliding resistance, as compared with a sliding member in which the surface exposure rate of the resin particles on the sliding surface is less than 3%.

[0010] <5> According to the present invention, it is possible to provide a sliding member which is excellent in maintaining sliding resistance, as compared with the case where the heat-resistant thermoplastic resin is a fluororesin. <6> According to the present invention, it is possible to provide a sliding member which is excellent in maintaining sliding resistance, as compared with the case where the heat-resistant thermoplastic resin is a polyphenylene sulfide resin.

[0011] <7> According to the present invention, it is possible to provide a sliding member which is excellent in maintaining sliding resistance, as compared with a case in which the resin particles are fluororesin particles. <8> According to the present invention, it is possible to provide a sliding member in which the thermosetting silicone resin particles are excellent in maintaining the sliding resistance compared to unmodified thermosetting silicone resin particles.

[0012] <9> According to the present invention, a sliding member having excellent maintenance of sliding resistance can be provided, compared to a case where the content of the resin particles is less than 1.0% by mass or more than 20.0% by mass with respect to the heat-resistant thermoplastic resin. <10> According to the invention, it is possible to provide a sliding member having excellent maintenance of sliding resistance, compared to a case where the content of the resin particles is less than 3% by mass or more than 25% by mass with respect to the heat-resistant thermoplastic resin.

[0013] <11> According to the invention, it is possible to provide a sliding member having excellent maintenance of sliding resistance, compared with a case in which the average particle size of the resin particles is less than 0.5 μm or exceeds 4 μm, a case in which the surface roughness Rsk of the sliding surface exceeds 0.6, or a case in which the surface exposure rate of the resin particles on the sliding surface is less than 3%. <12> According to the invention, it is possible to provide a sliding member having excellent retention of sliding resistance, compared to a case in which the heat-resistant thermoplastic resin is a fluororesin, the resin particles are fluororesin particles, or the content of the resin particles is less than 1.0 mass % or more than 20.0 mass % with respect to the heat-resistant thermoplastic resin.

[0014] <13> According to the invention, there is provided a fixing device that can suppress an increase in the rotation torque of the second rotating body and form an image with reduced gloss unevenness, as compared to a case in which a sliding member having a sliding surface comprising glass cloth and a fluororesin impregnated into the glass cloth is used. <14> According to the invention, a fixing device is provided that can suppress an increase in rotational torque of the second rotating body and form an image with reduced gloss unevenness, compared to when the inner surface of the second rotating body is made of polyimide resin. <15> According to the present invention, a fixing device is provided that can suppress an increase in the rotational torque of the second rotating body and form an image with reduced gloss unevenness, compared to a case in which the lubricant is composed only of fluoropolyether oil.

[0015] <16> According to the invention, an image forming apparatus is provided that can suppress an increase in the rotational torque of the second rotating body of the fixing device and form an image with reduced gloss unevenness, compared to the case where a sliding member having a sliding surface composed of glass cloth and a fluororesin impregnated into the glass cloth is used. [Brief description of the drawings]

[0016] [Figure 1] 1 is a schematic diagram illustrating an example of an image forming apparatus according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a schematic diagram illustrating an example of a fixing device according to the present embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of the present invention will be described as an example. The description and examples are merely illustrative of the embodiment, and are not intended to limit the scope of the present invention. In the present specification, the upper or lower limit of one numerical range may be replaced with the upper or lower limit of another numerical range. In addition, in the present specification, the upper or lower limit of the numerical range may be replaced with a value shown in the examples.

[0018] Each component may contain multiple types of the corresponding substance. When referring to the amount of each component in a composition, if the composition contains multiple substances corresponding to each component, the amount refers to the total amount of those multiple substances present in the composition, unless otherwise specified.

[0019] When describing the embodiments with reference to the drawings, components having substantially the same functions are given the same reference numerals throughout the drawings, and duplicated descriptions may be omitted.

[0020] <Sliding parts> The sliding surface of the sliding member according to this embodiment is configured to contain a heat-resistant thermoplastic resin other than a fluororesin, and resin particles having a siloxane group, the resin being other than the heat-resistant thermoplastic resin. The resin particles have an average particle size of 0.1 μm or more and 10 μm or less. The surface roughness Rsk of the sliding surface is 1.0 or less. The surface exposure rate of the resin particles on the sliding surface is 2% or more.

[0021] The sliding member according to this embodiment has the above-mentioned structure, and is therefore excellent in maintaining the sliding resistance. The reason for this is presumed to be as follows.

[0022] Generally, fluororesin is used for the sliding member because it provides low friction and heat resistance. Specifically, the sliding member may be a fluororesin sheet, a sheet in which fibrous fluororesin is woven, a sheet in which glass cloth is impregnated with fluororesin, or a sheet in which fluororesin particles are dispersed in polyimide resin. However, fluororesin wears rapidly and, due to its low strength, it deforms significantly when subjected to tensile or compressive force, which causes an increase in the sliding resistance of the sliding surface.

[0023] In addition, in a sheet in which glass cloth is impregnated with a fluororesin, when the fluororesin wears away, the sliding resistance of the sliding surface becomes dominated by the sliding resistance of the glass cloth, which in turn causes an increase in the sliding resistance of the sliding surface over time. Furthermore, in a sheet in which fluororesin particles are dispersed in polyimide resin, when the fluororesin particles wear away or fall off, the sliding resistance of the sliding surface becomes dominated by the sliding resistance of the polyimide resin, causing an increase in the sliding resistance of the sliding surface over time.

[0024] In contrast, the sliding member according to this embodiment contains resin particles having an average particle size of 0.1 μm or more and 10 μm or less and having a fluororesin group in a heat-resistant thermoplastic resin other than a fluororesin, and the surface roughness Rsk of the sliding surface and the surface exposure rate of the resin particles on the sliding surface are 2% or more. As a result, the exposed resin particles on the sliding surface exhibit lubricating properties, are less likely to separate from the sliding surface, and extend on the sliding surface to form a thin film.

[0025] From the above, it is presumed that the sliding member according to this embodiment is excellent in maintaining sliding resistance.

[0026] The sliding member according to this embodiment will be described in detail below.

[0027] The sliding surface of the sliding sheet is configured to contain a heat-resistant thermoplastic resin other than a fluororesin, and resin particles having a siloxane group, the resin particles being other than the heat-resistant thermoplastic resin. Specifically, the sliding sheet is composed of a single layer of a resin substrate layer containing a heat-resistant thermoplastic resin other than a fluororesin and resin particles having a siloxane group other than the heat-resistant thermoplastic resin. In other words, the sliding sheet is a resin sheet containing these components. However, the sliding sheet may be a laminate of a resin substrate layer constituting the sliding surface and another layer provided on the opposite side of the resin substrate layer to the sliding surface.

[0028] Examples of the heat-resistant thermoplastic resin include polyether ether ketone resin, polyphenylene sulfide resin, polyetherimide resin, polyphenylsulfone resin, polyethersulfone resin, polysulfone resin, and polyphenylsulfone resin.

[0029] Among these, the heat-resistant thermoplastic resin is preferably at least one resin selected from the group consisting of polyether ether ketone resins, polyphenylene sulfide resins, polyetherimide resins, and polyphenylsulfone resins, and more preferably at least one resin selected from the group consisting of polyether ether ketone resins and polyphenylene sulfide resins. These resins (particularly polyether ether ketone resin and polyphenylene sulfide resin) are preferred because they have high abrasion resistance, high toughness, and high elastic modulus.

[0030] Examples of resin particles having a siloxane group include resins having a polysiloxane structure in the main chain or side chain. Specific examples of resin particles having a siloxane group include thermosetting silicone resin particles, silicone oil gum, silicone elastomer, and siloxane-modified polyetherimide particles.

[0031] Among these, the resin particles having a siloxane group are preferably thermosetting silicone resin particles, since this component reduces the sliding resistance of the sliding surface and facilitates improving the maintenance of the sliding resistance.

[0032] Here, the thermosetting silicone resin particles are silicone resin particles that are cured by heat and have rubber-like elasticity. If the thermosetting silicone resin particles are unmodified thermosetting silicone resin particles, the affinity with the lubricant is increased, and the increase in the rotation torque of the pressure belt 40 is easily suppressed, so that it is preferable. Silicone gum is silicone oil with a molecular weight of 300,000 or more molded into pellets.

[0033] The average particle size of the resin particles having a siloxane group is from 0.1 to 10 μm. From the viewpoint of improving the maintenance of the sliding resistance, the average particle size is preferably from 0.5 to 4 μm, more preferably from 1 to 3 μm.

[0034] The average particle size of the resin particles is measured as follows. A sample having a cut surface cut along the thickness direction of the sliding member to be measured is obtained. The cut surface of the sample is observed by an electron microscope, the area value of the resin particles is obtained by image analysis, and the circle-equivalent diameter is calculated from the area value. This calculation of the circle-equivalent diameter is performed for 100 resin particles. Then, the 50% diameter (D50) of the volume-based cumulative frequency of the obtained circle-equivalent diameters is taken as the average particle size of the resin particles.

[0035] The content of the resin particles having a siloxane group is preferably from 1.0 to 20.0% by mass, more preferably from 2.0 to 15.0% by mass, and even more preferably from 5.0 to 10.0% by mass, based on the heat-resistant thermoplastic resin. By setting the content of the resin having a siloxane group within the above range, it becomes easy to adjust the surface roughness Rsk of the sliding surface and the surface exposure rate of the resin particles on the sliding surface to within the above range. Therefore, the sliding sheet has wear resistance and the sliding resistance is reduced, and the maintenance of the sliding resistance is easily improved.

[0036] The resin substrate layer constituting the sliding surface may contain other components in addition to the resin, such as a conductive agent, a filler for improving mechanical strength, an antioxidant for preventing thermal deterioration, a surfactant, and a heat-resistant anti-aging agent.

[0037] In the sliding member according to the present embodiment, the surface roughness Rsk of the sliding surface is 1.0 or less. From the viewpoint of improving the maintenance of the sliding resistance, the surface roughness Rsk is preferably 0.6 or less, and more preferably 0.5 or less. However, from the viewpoint of the amount of lubricant retained and the resistance to catching with the counter material due to the shape, the lower limit of the surface roughness Rsk is, for example, 0.2 or more. The above range of the surface roughness Rsk indicates an absolute value. The surface roughness Rsk is the skewness Rsk of the roughness curve in the sliding direction on the sliding surface.

[0038] The surface roughness Rsk of the sliding surface is measured in accordance with JIS B0601 (2001). Specifically, it is measured under the following conditions using a surface roughness meter (Surfcom 1500SD, manufactured by Tokyo Seimitsu Co., Ltd.). Measurement type: Roughness measurement Measurement length: 1.0mm Cutoff wavelength: 0.025mm Measurement range: ±32.0μm ·Measurement speed: 0.03mm / s Cutoff type: 2RC (non-phase compensated) Tilt correction least squares linear correction · λs cutoff 300 λs cutoff: 0.0833μm

[0039] In the sliding member according to the present embodiment, the surface exposure rate of the resin particles on the sliding surface is 2% or more. From the viewpoint of improving the maintenance of the sliding resistance, the surface exposure rate of the resin particles is preferably 3% or more, and more preferably 5% or more. However, from the viewpoint of the abrasion resistance strength of the sliding surface, the upper limit of the surface exposure rate of the resin particles is, for example, 10% or less.

[0040] The surface exposure rate of the resin particles is measured as follows. A sample having a sliding surface is obtained from the sliding member to be measured. The sliding surface of the sample is observed with an electron microscope at a magnification of 2000 times, and the area value of the exposed resin particles is obtained by image analysis. The ratio of the area value of the exposed resin particles to the area value of the observation field is calculated. This calculation of the ratio of the area value of the resin particles is performed for five fields of view. Then, the arithmetic average value of the ratio of the area value of the resin particles, which is the 50% diameter (D50) in the cumulative frequency based on the volume of the obtained circle equivalent diameter, is determined as the surface exposure rate of the resin particles.

[0041] Here, the surface roughness Rsk of the sliding surface and the surface exposure rate of the resin particles on the sliding surface are adjusted, for example, by the average particle size and content of the resin particles.

[0042] <Fixing device / image forming device> The fixing device according to this embodiment is a specific fixing device, and includes a first rotating body, a second rotating body arranged in contact with the first rotating body, a pressing member arranged on the inner circumferential surface of the second rotating body and pressing the second rotating body against the first rotating body from the inner circumferential surface of the second rotating body, a sliding member interposed between the inner circumferential surface of the second rotating body and the pressing member, and a lubricant interposed between the inner circumferential surface of the second rotating body and the sliding member. Hereinafter, a fixing device including these members will also be referred to as a "specific fixing device." The fixing device according to this embodiment uses the sliding member according to this embodiment as a sliding member.

[0043] The image forming apparatus according to the present embodiment includes: An image carrier; a latent image forming device for forming a latent image on a surface of an image carrier; a developing device for developing the latent image into a toner image using a developer; a transfer device for transferring the developed toner image onto a recording medium; a fixing device that fixes the toner image on the recording medium; Equipped with. In the image forming apparatus according to the present embodiment, the fixing device according to the present embodiment is applied as a fixing device.

[0044] In the fixing device and image forming apparatus according to this embodiment, when the sliding member according to the above-described embodiment is applied as a sliding member, for example, an increase in the rotational torque of the second rotating body of the fixing device can be suppressed and an image with reduced gloss unevenness can be formed.

[0045] In particular, in the fixing device and image forming apparatus according to this embodiment, from the viewpoint of suppressing an increase in the rotational torque of the second rotating body and reducing uneven gloss, it is preferable that the inner surface of the second rotating body is composed of a resin having at least one type of group selected from the group consisting of an amide group, an imide group, a ketone group, and a sulfide group. From the same viewpoint, the lubricant preferably contains an oil having a siloxane group as a main chain.

[0046] Conventionally, to form an image in an electrophotographic image forming apparatus such as a printer, a copier, or a facsimile, a toner image is transferred onto a recording medium such as recording paper, and then the recording medium onto which the toner image has been transferred is heated and pressurized by a fixing device, thereby fixing the toner image to the surface of the recording medium.

[0047] Various types of fixing devices have been proposed in the past, and the above-mentioned specific fixing device is one of them.

[0048] In a specific fixing device, a fluororesin that provides low friction and heat resistance is used for the sliding member. Specifically, a fluororesin sheet, a sheet woven with fibrous fluororesin, or a sheet impregnated with glass cloth is used for the sliding member. However, fluororesin wears rapidly and, due to its low strength, it deforms significantly when subjected to tensile or compressive force, which causes an increase in the rotational torque of the second rotating body. In addition, sheets made of woven fibrous fluororesin and sheets made of glass cloth impregnated with fluororesin have uneven surfaces, which causes stress concentration at the protruding parts, resulting in uneven gloss in the obtained image.

[0049] In addition, in a specific fixing device, for example, PTFE grease containing perfluoropolyether oil is used as a lubricant. However, the affinity of the lubricant with the inner circumferential surface of the second rotating body and the sliding surface of the sliding member is low, and it becomes difficult for a thin film of the lubricant to be interposed between the inner circumferential surface of the second rotating body and the sliding surface of the sliding member over time, which also causes an increase in the rotational torque of the second rotating body.

[0050] In contrast, in the fixing device and image forming apparatus according to the present embodiment, at least one group selected from the group consisting of an amide group, an imide group, a ketone group, and a sulfide group is present on the inner circumferential surface of the second rotating body. The inner circumferential surface of the second rotating body on which these polar groups are present has a high affinity with oil having a siloxane group as a main chain, which is used as a lubricant. In addition, the sliding surface of the sliding member contains siloxane groups derived from the resin particles having the siloxane groups, and therefore the sliding surface of the sliding member also has a high affinity with the oil having a siloxane group as a main chain, which is used as a lubricant. This makes it possible to suppress an increase in the rotation torque of the second rotating body and form an image with reduced gloss unevenness.

[0051] In addition, since the sliding surface of the sliding member contains a heat-resistant thermoplastic resin other than fluororesin, wear is unlikely to progress in a short period of time, thereby reducing an increase in the rotational torque of the second rotating body.

[0052] Hereinafter, an example of an image forming apparatus according to the present embodiment will be described with reference to the drawings.

[0053] Fig. 1 is a schematic diagram showing an example of an image forming apparatus according to the present embodiment, and Fig. 2 is a schematic diagram showing an example of a fixing device according to the present embodiment.

[0054] (Configuration of Image Forming Apparatus) 1, the image forming apparatus 100 according to the present embodiment includes first to fourth electrophotographic process cartridges 10Y, 10M, 10C, and 10K (examples of image forming units) that output images of each color of yellow (Y), magenta (M), cyan (C), and black (K) based on color-separated image data. These process cartridges 10Y, 10M, 10C, and 10K are arranged side by side and spaced apart from each other along the outer circumferential surface of the intermediate transfer belt 20. These process cartridges 10Y, 10M, 10C, and 10K are detachable from the image forming apparatus main body.

[0055] Above each of the process cartridges 10Y, 10M, 10C, and 10K (in FIG. 1), an intermediate transfer belt 20 serving as an intermediate transfer body is provided with its outer circumferential surface facing each of the process cartridges. The intermediate transfer belt 20 is wound around a drive roller 22 and a support roller 24 that are spaced apart from each other and are in contact with the inner circumferential surface of the intermediate transfer belt 20, and is arranged while being tensioned, so that it travels endlessly in a direction from the first process cartridge 10Y to the fourth process cartridge 10K.

[0056] The support roller 24 is pressed in a direction away from the drive roller 22 by an elastic member such as a spring (not shown), and tension is applied to the intermediate transfer belt 20 wound between them. In addition, an intermediate transfer body cleaning device 20a is provided on the outer circumferential surface of the intermediate transfer belt 20 facing the drive roller 22.

[0057] Since the first to fourth process cartridges 10Y, 10M, 10C, and 10K have substantially the same configuration, the first process cartridge 10Y that forms a yellow image and is disposed upstream in the direction in which the intermediate transfer belt runs will be described here as a representative example. Note that the same reference numerals as those in the first process cartridge 10Y are used to designate the same parts, but with magenta (M), cyan (C), and black (K) instead of yellow (Y), and descriptions of the second to fourth process cartridges 10M, 10C, and 10K will be omitted.

[0058] The first process cartridge 10Y has a photoconductor 1Y that acts as an image carrier. Around the photoconductor 1Y, a charging roller (one example of a charging device) 2Y that charges the surface of the photoconductor 1Y to a predetermined potential, a developing device 4Y that supplies the charged toner contained in the developer to the electrostatic latent image to develop the electrostatic latent image, and a photoconductor cleaning device 6Y that removes the toner remaining on the surface of the photoconductor 1Y after the primary transfer are arranged in this order. These are integrally configured in a housing 11Y (casing). Similarly, the first process cartridges 10M to 10Y have each member integrally configured in a housing 11M to 11Y (casing).

[0059] Together with the first process cartridge 10Y, a primary transfer roller 5Y (an example of a primary transfer device) that transfers the developed toner image onto the intermediate transfer belt 20, and an exposure device 3 that exposes the charged surface to a laser beam 3Y based on a color-separated image signal to form an electrostatic latent image are arranged to form an image forming section. The charging roller 2Y and the exposure device 3 correspond to an example of a latent image forming device.

[0060] The primary transfer roller 5Y is disposed inside the intermediate transfer belt 20, and is provided at a position facing the photoconductor 1Y. Furthermore, a bias power supply (not shown) that applies a primary transfer bias is connected to each of the primary transfer rollers 5Y, 5M, 5C, and 5K. Each bias power supply varies the transfer bias applied to each primary transfer roller under the control of a control unit (not shown).

[0061] (Configuration of Fixing Device) 2, the fixing device 28 includes a heating roll 30 (an example of a first rotating body) and a pressure belt 40 (an example of a second rotating body), which are disposed opposite to each other. The pressure belt 40 is pressed against the heating roll 30 by a pressure pad 50 (an example of a pressing member) disposed inside the periphery thereof, and is guided along a belt running guide 52 while being pressed against the heating roll 30 to form a contact portion, and is driven by the driving force from the heating roll 30. A sliding sheet 60 (an example of a sliding member) is interposed between the pressure belt 40 and the pressure pad 50. A lubricant 62 (an example of a lubricant) is interposed between the sliding sheet 60 and the inner circumferential surface of the pressure belt 40. The lubricant 62 is supplied to the inner circumferential surface of the pressure belt 40 by a lubricant supplying member 64 provided in a part of the belt running guide 52, for example, and is interposed between the sliding sheet 60 and the inner circumferential surface of the pressure belt 40. In FIG. 2, T indicates a toner image.

[0062] - Heating roll 30 (an example of a first rotating body) - The heating roll 30 is configured by sequentially forming an elastic layer 30b and a release layer 30c on a hollow metal core 30a made of metal and having a heat source 31 such as a halogen lamp inside.

[0063] The metal core 30a is, for example, a cylindrical body made of metal such as aluminum or stainless steel. The elastic layer 30b is, for example, made of HTV silicone rubber or fluororubber (JIS-A rubber hardness of about 45 degrees, rubber hardness is measured by a Teclock spring-type A-type hardness tester under a load of 1,000 gf in accordance with JIS K6301) with a thickness of about 2 mm to 5 mm. The release layer 30c is, for example, made of fluororubber, silicone rubber, fluororesin, etc. with a thickness of 20 μm to 50 μm. Of course, it is not limited to these and may be made of a conventionally known material.

[0064] The heating roll 30 is a fixing roll, and its speed is adjusted by a driving source (not shown), and it is rotated at a peripheral speed of, for example, 260 mm / sec. The outer diameter of the heating roll 30 is generally, for example, about 25 mm to 80 mm.

[0065] The surface temperature of the heating roll 30 is detected by a temperature sensor (not shown) that contacts the surface, and is controlled by a control circuit (not shown) so that the surface temperature is kept at 175° C., for example.

[0066] -Pressure belt 40 (an example of a second rotating body)- The inner circumferential surface of the pressure belt 40 is made of a resin having at least one group selected from the group consisting of an amide group, an imide group, a ketone group, and a sulfide group. This resin is a heat-resistant resin. Hereinafter, the term "heat-resistant" means a property that the resin does not melt or decompose even when the temperature of the fixing device (e.g., the fixing temperature) is reached. The same applies hereinafter.

[0067] Specifically, the pressure belt 40 has a resin substrate layer that constitutes the inner circumferential surface and contains a resin having at least one type of group selected from the group consisting of an amide group, an imide group, a ketone group, and a sulfide group. The pressure belt 40 may be a single layer body of a resin substrate layer constituting the inner circumferential surface of the pressure belt 40, or a laminate having a resin substrate layer constituting the inner circumferential surface of the pressure belt 40, an elastic layer provided on the resin substrate layer, and a release layer provided on the elastic layer, or a laminate having a resin substrate layer constituting the inner circumferential surface of the pressure belt 40 and a release layer provided on the resin substrate layer.

[0068] The resin substrate layer will be described. Specific examples of resins having at least one type of group selected from the group consisting of an amide group, an imide group, a ketone group, and a sulfide group include polyimide resins, polyamideimide resins, polyether ether ketone resins, polyphenylene sulfide resins, polyethersulfone resins, polysulfone resins, and polyphenylsulfone resins.

[0069] Among these, the resin is preferably at least one resin selected from the group consisting of polyimide resin, polyamideimide resin, polyether ether ketone resin, and polyphenylene sulfide resin, and more preferably a polyimide resin. These resins (particularly polyimide resins) have high abrasion resistance and high affinity with lubricants, which makes it easier to suppress an increase in the rotational torque of the pressure belt 40.

[0070] Examples of polyimide resins include imidized products of polyamic acids (precursors of polyimide resins), which are polymers of tetracarboxylic dianhydrides and diamine compounds. An example of the polyimide resin is a resin having a structural unit represented by the following general formula (I).

[0071] [ka]

[0072] In general formula (I), R 1 represents a tetravalent organic group, R 2 represents a divalent organic group. R 1 Examples of the tetravalent organic group represented by the formula (1) include an aromatic group, an aliphatic group, a cyclic aliphatic group, a group in which an aromatic group and an aliphatic group are combined, and groups in which these groups are substituted. Specific examples of the tetravalent organic group include residues of tetracarboxylic dianhydrides, which will be described later. R 2 Examples of the divalent organic group represented by the formula (1) include an aromatic group, an aliphatic group, a cyclic aliphatic group, a group in which an aromatic group and an aliphatic group are combined, and groups in which these groups are substituted. Specific examples of the divalent organic group include residues of diamine compounds described below.

[0073] Specific examples of tetracarboxylic dianhydrides used as raw materials for polyimide resins include pyromellitic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, Examples of the dianhydride include 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3,3',4-biphenyltetracarboxylic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 2,2'-bis(3,4-dicarboxyphenyl)sulfonic dianhydride, perylene-3,4,9,10-tetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)ether dianhydride, and ethylenetetracarboxylic dianhydride.

[0074] Specific examples of diamine compounds used as raw materials for polyimide resins include 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenylmethane, 3,3'-dichlorobenzidine, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfone, 1,5-diaminonaphthalene, m-phenylenediamine, p-phenylenediamine, 3,3'-dimethyl 4,4'-biphenyldiamine, benzidine, and 3,3'-dimethyl Benzidine, 3,3'-dimethoxybenzidine, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenylpropane, 2,4-bis(β-amino tert-butyl)toluene, bis(p-β-amino-tert-butylphenyl)ether, bis(p-β-methyl-δ-aminophenyl)benzene, bis-p-(1,1-dimethyl-5-amino-pentyl)benzene, 1-isopropyl-2,4-m-phenylenediamine, m-xylylenediamine, p-xylylenediamine, di(p -aminocyclohexyl)methane, hexamethylenediamine, heptamethylenediamine, octamethylenediamine, nonamethylenediamine, decamethylenediamine, diaminopropyltetramethylene, 3-methylheptamethylenediamine, 4,4-dimethylheptamethylenediamine, 2,11-diaminododecane, 1,2-bis-3-aminopropoxyethane, 2,2-dimethylpropylenediamine, 3-methoxyhexamethylenediamine, 2,5-dimethylheptamethylenediamine, Examples include 3-methylheptamethylenediamine, 5-methylnonamethylenediamine, 2,17-diaminoeicosadecane, 1,4-diaminocyclohexane, 1,10-diamino-1,10-dimethyldecane, 12-diaminooctadecane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, piperazine, H2N(CH2)3O(CH2)2O(CH2)NH2, H2N(CH2)3S(CH2)3NH2, and H2N(CH2)3N(CH3)2(CH2)3NH2.

[0075] The polyamide-imide resin may be a resin having an imide bond and an amide bond in the repeating unit. More specifically, the polyamide-imide resin may be a polymer of a trivalent carboxylic acid compound (also called tricarboxylic acid) having an acid anhydride group, and a diisocyanate compound or a diamine compound.

[0076] As the tricarboxylic acid, trimellitic anhydride and its derivatives are preferable. In addition to the tricarboxylic acid, tetracarboxylic dianhydride, aliphatic dicarboxylic acid, aromatic dicarboxylic acid, etc. may be used in combination.

[0077] Examples of the diisocyanate compound include 3,3'-dimethylbiphenyl-4,4'-diisocyanate, 2,2'-dimethylbiphenyl-4,4'-diisocyanate, biphenyl-4,4'-diisocyanate, biphenyl-3,3'-diisocyanate, biphenyl-3,4'-diisocyanate, 3,3'-diethylbiphenyl-4,4'-diisocyanate, 2,2'-diethylbiphenyl-4,4'-diisocyanate, 3,3'-dimethoxybiphenyl-4,4'-diisocyanate, 2,2'-dimethoxybiphenyl-4,4'-diisocyanate, naphthalene-1,5-diisocyanate, and naphthalene-2,6-diisocyanate. The diamine compound has the same structure as the above-mentioned isocyanate and has an isocyanato group. Compounds having an amino group instead of the above may be mentioned. The resin substrate layer may contain other components in addition to the resin, such as a conductive agent, a filler for improving mechanical strength, an antioxidant for preventing thermal deterioration, a surfactant, and a heat-resistant anti-aging agent.

[0078] Here, an example has been given in which the first rotating body is a heating roll and the second rotating body is a pressure belt, but the present invention also includes an embodiment in which the first rotating body is a pressure roll and the second rotating body is a heating belt. When the first rotating body is a pressure roll, the configuration of the pressure roll is preferably the same as the configuration of the heating roll 30 described above. When the second rotating body is a heating belt, the configuration of the heating belt is preferably the same as the configuration of the pressure belt 40 described above. In particular, when the second rotating body is a heating belt, the second rotating body may be a single layer body of a resin substrate layer constituting the inner circumferential surface of the heating belt, or a laminate having a resin substrate layer constituting the inner circumferential surface of the heating belt, an elastic layer provided on the resin substrate layer, and a release layer provided on the elastic layer, or a laminate having a resin substrate layer constituting the inner circumferential surface of the heating belt and a release layer provided on the resin substrate layer, or a laminate in which a metal layer and an elastic layer are provided on the resin substrate layer constituting the inner circumferential surface of the heating belt, and a release layer is provided on the elastic layer.

[0079] The elastic layer will now be described. The elastic layer is comprised of a heat resistant elastic material. Examples of the heat-resistant elastic material include silicone rubber and fluororubber. Examples of silicone rubber include RTV (Room Temperature Vulcanizing) silicone rubber, HTV (High Temperature Vulcanizing) silicone rubber, and liquid silicone rubber. Specific examples of silicone rubber include polydimethyl silicone rubber, methyl vinyl silicone rubber, methyl phenyl silicone rubber, and fluoro silicone rubber. Examples of the fluororubber include vinylidene fluoride rubber, tetrafluoroethylene / propylene rubber, tetrafluoroethylene / perfluoromethylvinyl ether rubber, phosphazene rubber, and fluoropolyether.

[0080] The elastic layer may contain other components, such as fillers, conductive agents, softeners (paraffin-based, etc.), processing aids (stearic acid, etc.), antioxidants (amine-based, etc.), vulcanizing agents (sulfur, metal oxides, peroxides, etc.), and functional fillers (alumina, etc.).

[0081] The release layer will now be described. The release layer includes, for example, a heat resistant release material. Examples of the heat-resistant release material include fluororubber, fluororesin, silicone resin, and polyimide resin. Among these, fluororesins are preferable as the heat-resistant release material.Specific examples of fluororesins include polytetrafluoroethylene (PTFE); tetrafluoroethylene-perfluoromethylvinylether copolymer (MFA), tetrafluoroethylene-perfluoroethylvinylether copolymer (EFA), tetrafluoroethylene-perfluoropropylvinylether copolymer, and other tetrafluoroethylene-perfluoroalkylvinylether copolymers (PFA).Further examples include tetrafluoroethylene-hexafluoropropylene copolymer (FEP), ethylene-tetrafluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), polyvinyl fluoride (PVF), and the like. Among these, polytetrafluoroethylene (PTFE) and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymers (PFA) such as tetrafluoroethylene-perfluoromethyl vinyl ether copolymer (MFA) and tetrafluoroethylene-perfluoroethyl vinyl ether copolymer (EFA) are preferably used, particularly from the standpoint of heat resistance, mechanical properties, and the like. The thickness of the release layer is preferably set to 5 μm to 100 μm, and more preferably 10 μm to 30 μm.

[0082] -Pressing pad 50 (an example of a pressing member)- The pressure pad 50 has two pressure parts 51a, 51b of different hardness along the traveling direction of the recording medium P. The pressure part 51a on the recording medium P entry side of the pressure pad 50 is made of a rubber-like elastic member, and the pressure part 51b on the recording medium P exit side is made of a hard pressure applying member such as metal, so that the pressure of the contact area is higher on the recording medium P exit side than on the recording medium P entry side. The pressure parts 51a, 51b are supported by a holder 51c, and press the heating roll 30 from the inner circumferential surface of the pressure belt 40 via a sliding sheet 60 (an example of a sliding member).

[0083] -Sliding sheet 60 (an example of a sliding member)- The sliding sheet 60 is made of the sliding member according to this embodiment.

[0084] -Lubricant 62 (an example of a lubricant)- The lubricant 62 includes an oil having a siloxane group as the main chain. The oil having a siloxane group in the main chain is an oil having a polysiloxane structure in the main chain, and examples of the oil include silicone oil and various modified silicone oils.

[0085] Here, the oil having a siloxane group as the main chain is preferably an oil having a structure having a polar group in the side chain. If the oil has a polar group, it has a high affinity with the inner circumferential surface of the pressure belt 40, and the increase in the rotation torque of the pressure belt 40 is easily suppressed. Examples of the polar group include an amino group, a hydroxyl group, a carboxyl group, a sulfonic acid group, a phenyl group, an epoxy group, a mercapto group, a methacryl group, a phenol group, a polyether group, and a fluorine group. Among these, an amino group is preferred as the polar group, from the viewpoint of high affinity with the inner circumferential surface of the pressure belt 40 and easy suppression of an increase in the rotation torque of the pressure belt 40.

[0086] Specific examples of the lubricant 62 include modified oils such as alkyl-modified silicone oil (dimethyl-modified silicone oil, etc.), amino-modified silicone oil, methylphenyl-modified silicone oil, epoxy-modified silicone oil, phenol-modified silicone oil, polyether-modified silicone oil, and fluorine-modified silicone oil. Among these, amino-modified silicone oil is preferable as the lubricant 62 from the viewpoint of high affinity with the inner circumferential surface of the pressure belt 40 and easy suppression of an increase in the rotation torque of the pressure belt 40 .

[0087] The lubricant 62 may contain other components in addition to oil, such as grease (such as silicone grease), a thermal conductive agent, an antioxidant, a surfactant, silicone particles, an organic metal salt, and a hindered amine.

[0088] (Image forming operation of image forming apparatus) The image forming operation of the image forming apparatus according to this embodiment will be described below, taking the operation of forming a yellow image in the first process cartridge 10Y as a representative example.

[0089] First, prior to the image forming operation, the surface of the photoconductor 1Y is charged to a potential of, for example, about −600V or more and −800V or less by the charging roller 2Y.

[0090] The photoconductor 1Y is formed, for example, by laminating a photosensitive layer on a conductive substrate. This photosensitive layer, for example, is normally highly resistive, but when irradiated with a laser beam 3Y, the resistivity of the portion irradiated with the laser beam changes. A laser beam 3Y is output to the charged surface of the photoconductor 1Y via an exposure device 3 according to image data for yellow sent from a control unit (not shown). The laser beam 3Y is irradiated to the photosensitive layer on the surface of the photoconductor 1Y, thereby forming an electrostatic latent image of a yellow print pattern on the surface of the photoconductor 1Y.

[0091] The electrostatic latent image thus formed on the photoconductor 1Y is rotated to a development position as the photoconductor 1Y travels. Then, at this development position, the electrostatic latent image on the photoconductor 1Y is made into a visible image (toner image) by the developing device 4Y.

[0092] The developing device 4Y contains a developer containing, for example, yellow toner and a carrier. The yellow toner is triboelectrically charged by being stirred inside the developing device 4Y, and has a charge of the same polarity (negative polarity) as the charge on the photoconductor 1Y. As the surface of the photoconductor 1Y passes through the developing device 4Y, the yellow toner electrostatically adheres only to the discharged latent image portion on the surface of the photoconductor 1Y, and the latent image is developed with the yellow toner. The photoconductor 1Y on which the yellow toner image has been formed continues to travel, and the toner image developed on the photoconductor 1Y is transported to the primary transfer position.

[0093] When the yellow toner image on the photoconductor 1Y is transported to the primary transfer position, a primary transfer bias is applied to the primary transfer roller 5Y, and an electrostatic force from the photoconductor 1Y toward the primary transfer roller 5Y acts on the toner image, and the toner image on the photoconductor 1Y is transferred onto the intermediate transfer belt 20. The transfer bias applied at this time has a polarity (+) opposite to the polarity (-) of the toner, and in the first process cartridge 10Y, for example, the transfer bias is controlled to a constant current of about +10 μA by a control unit (not shown).

[0094] Further, the primary transfer bias applied to the primary transfer rollers 5M, 5C, and 5K subsequent to the second process cartridge 10M is also controlled in the same manner.

[0095] In this manner, the intermediate transfer belt 20 onto which the yellow toner image has been transferred in the first process cartridge 10Y is transported successively through the second to fourth process cartridges 10M, 10C, and 10K, and the toner images of each color are similarly superimposed and multi-transferred thereon.

[0096] The intermediate transfer belt 20 onto which the toner images of all colors have been transferred in multiple layers through the first to fourth process cartridges reaches a secondary transfer section that is composed of the intermediate transfer belt 20, a support roller 24 that contacts the inner circumferential surface of the intermediate transfer belt 20, and a secondary transfer roller (an example of a secondary transfer device) 26 arranged on the image bearing surface side of the intermediate transfer belt 20. Meanwhile, the recording medium P is fed between the secondary transfer roller 26 and the intermediate transfer belt 20 via a supply mechanism, and a secondary transfer bias is applied to the support roller 24. The transfer bias applied at this time has a (-) polarity that is the same as the (-) polarity of the toner, and an electrostatic force from the intermediate transfer belt 20 toward the recording medium P acts on the toner image, so that the toner image on the intermediate transfer belt 20 is transferred onto the recording medium P. The secondary transfer bias at this time is determined according to the resistance detected by a resistance detection means (not shown) that detects the resistance of the secondary transfer section, and is controlled at a constant voltage. The intermediate transfer belt 20, the primary transfer roller 5Y, and the secondary transfer roller 26 correspond to an example of a transfer device.

[0097] Thereafter, the recording medium P is sent into the fixing device 28 and passed through a contact area formed by the pressure contact between the heating roll 30, which is driven to rotate in the direction of the arrow, and the pressure belt 40. At this time, the recording medium P is passed through so that the surface of the recording medium P on which the unfixed toner image is formed faces the surface of the heating roll 30. When the recording medium P passes through this contact area, heat and pressure are applied to the recording medium P, so that the unfixed toner image is fixed to the recording medium P. After passing through the contact area, the fixed recording medium is peeled off from the heating roll 30 and discharged from the fixing device 28.

[0098] In this manner, the fixing process is completed, and the color image is permanently fixed onto the recording medium P. The recording medium P on which the color image has been fixed is conveyed toward the discharge section, and a series of color image forming operations is completed. EXAMPLES

[0099] Examples will be described below, but the present invention is not limited to these examples. In the following description, unless otherwise specified, all "parts" and "%" are based on mass.

[0100] <Preparation of pressure belt> (Preparation of Pressure Belt (1)) A silicone-based release agent was applied to the surface of an aluminum cylindrical core, which had been shot blasted to create an uneven surface, and baked at 300°C for 1 hour. After that, a polyimide (PI) precursor in N-methylpyrrolidone solution was dip-coated onto the surface, and dried at 100°C for 1 hour. This formed a resin substrate layer that constitutes the inner surface of the pressure belt. Next, a fluororesin dispersion (specifically, a PTFE dispersion) was coated on the outer surface of the resin substrate layer, and then it was dried at 60°C for 10 minutes in a baking furnace, gradually heated to 380°C, baked for 20 minutes, and then cooled to room temperature to form a release layer. Thereafter, the resin substrate layer on which the release layer was formed was removed from the core and cut to the desired size by a cutter to obtain the pressure belt (1).

[0101] (Preparation of Pressure Belt (2)) A silicone-based release agent was applied to the surface of an aluminum cylindrical core body, which had been shot blasted to form an uneven surface, and baked at 300°C for 1 hour. After that, the surface was dipped into a varnish made by dissolving polyamide-imide resin in N-methylpyrrolidone, and dried at 120°C for 1 hour. This formed a resin substrate layer that constitutes the inner circumferential surface of the pressure belt. Next, a fluororesin dispersion (specifically, a PTFE dispersion) was coated on the outer surface of the resin substrate layer, and then dried at 60°C for 10 minutes in a baking furnace. After that, the coating was gradually heated to 320°C and baked for 20 minutes, and then cooled to room temperature to form a release layer. Thereafter, the resin substrate layer on which the release layer was formed was removed from the core and cut to the desired size by a cutter to obtain the pressure belt (2).

[0102] (Preparation of Pressure Belt (3)) Polyether ether ketone (PEEK) resin pellets (450G manufactured by Victrex) were placed in a material supply hopper in a single-screw extruder, the barrel temperature was set to 360°C, the tubular die temperature for discharging the resin was set to 380°C, and the resin was melt-extruded while being taken up by a take-up machine. Immediately afterwards, the inner surface of the cylindrical molten resin was brought into contact with the surface of a 30 mm cylindrical sizing die, and the cooled film was taken up into a cylindrical shape while cooling air was blown onto the outer surface, and cut by a cutter to obtain a pressure belt (3).

[0103] (Preparation of Pressure Belt (4)) Polyphenylene sulfide (PPS) resin pellets (A900 manufactured by Toray Industries, Inc.) were placed in the material supply hopper in a single-screw extruder, the barrel temperature was set to 260°C, the tubular die temperature for discharging the resin was set to 300°C, and the resin was melt-extruded while being taken up by a take-up machine. Immediately afterwards, the inner surface of the cylindrical molten resin was brought into contact with the surface of a 30 mm cylindrical sizing die, and the cooled film was taken up into a cylindrical shape while cooling air was blown onto the outer surface, and cut by a cutter to obtain a pressure belt (4).

[0104] <Preparation of sliding sheet> (Preparation of sliding sheet (1)) Polyether ether ketone (PEEK) resin (Victrex 450G, manufactured by Victrex) was melted at 380°C in a twin-screw melt kneader (twin-screw melt kneader L / D60, manufactured by Parker Corporation). 10 parts by mass of unmodified thermosetting silicone resin particles (KMP590, manufactured by Shin-Etsu Chemical Co., Ltd., average particle size = 2 μm) were fed into 100 parts by mass of the molten PEEK resin from the side of the kneader using a side feeder and melt-kneaded. The kneaded molten material was placed in a water tank, cooled and solidified, and cut to the desired size to obtain mixed resin pellets containing the silicone resin particles. The obtained mixed resin pellets were put into a single screw extruder, and the molten mixed resin was extruded into a sheet from a T-die mold (melt discharge gap 200 μm) heated to 380° C., and then wrapped around a cooling roll at 190° C. to cool, and the cooled sheet was shaped at a pressure of 40 MPa between a roll heated to 250° C. with a 100 mesh SUS wire netting wrapped around its surface and a roll with a heat-resistant silicone rubber on its surface to obtain a rugged sheet. The rugged sheet was cut to a predetermined size to obtain a sliding sheet (1).

[0105] (Preparation of sliding sheet (2)) A sliding sheet (2) was obtained in the same manner as the sliding sheet (1), except that the amount of unmodified thermosetting silicone resin particles ("KMP590" manufactured by Shin-Etsu Chemical Co., Ltd.) was changed to 15 parts by mass.

[0106] (Preparation of sliding sheet (3)) Polyphenylene sulfide (PPS) resin (TORELINA A900, manufactured by Toray Industries, Inc.) was melted at 300°C in a twin-screw melt kneader (twin-screw melt kneader L / D60, manufactured by Parker Corporation), and 10 parts by mass of unmodified thermosetting silicone resin particles (KMP590, manufactured by Shin-Etsu Chemical Co., Ltd., average particle size = 2 μm) were fed into 100 parts by mass of the molten PPS resin from the side of the kneader using a side feeder and melt-kneaded. The kneaded molten material was placed in a water tank where it was cooled and solidified, and then cut to the desired size to obtain mixed resin pellets containing the silicone resin particles. The resulting mixed resin pellets were put into a single-screw extruder, and the molten mixed resin was extruded into a sheet from a T-die mold (melt discharge gap 200 μm) heated to 300° C., and then wrapped around a cooling roll at 160° C. to cool, and the cooled sheet was shaped at a pressure of 40 MPa between a roll heated to 250° C. with a 100 mesh SUS wire netting wrapped around its surface and a roll with a heat-resistant silicone rubber on its surface to obtain a rugged sheet. The rugged sheet was cut to a predetermined size to obtain a sliding sheet (3).

[0107] (Preparation of sliding sheet (4)) A sliding sheet (2) was obtained in the same manner as the sliding sheet (1), except that the amount of unmodified thermosetting silicone resin particles ("KMP590" manufactured by Shin-Etsu Chemical Co., Ltd.) was changed to 20 parts by mass.

[0108] (Preparation of sliding sheet (C1)) A sliding sheet (C1) was obtained in the same manner as the sliding sheet (1), except that 10 parts by mass of acrylic-modified silicone particles ("Chaline R180S" manufactured by Nissin Chemical Industry Co., Ltd., average particle size = 30 μm) were used instead of unmodified thermosetting silicone resin particles ("KMP590" manufactured by Shin-Etsu Chemical Co., Ltd.).

[0109] (Preparation of sliding sheet (C2)) A sliding sheet (C2) was obtained in the same manner as the sliding sheet (1), except that 10 parts by mass of acrylic-modified silicone resin particles ("Chaline R200" manufactured by Nissin Chemical Industry Co., Ltd., average particle size = 2 μm) were crushed to an average particle size of 0.08 μm, instead of unmodified thermosetting silicone resin particles ("KMP590" manufactured by Shin-Etsu Chemical Co., Ltd.).

[0110] (Preparation of sliding sheet (C3)) A sliding sheet (C3) was obtained in the same manner as the sliding sheet (1), except that 25 parts by mass of acrylic-modified silicone resin particles ("Chaline R200" manufactured by Nissin Chemical Industry Co., Ltd., average particle size = 2 μm) were crushed to an average particle size of 0.08 μm, instead of unmodified thermosetting silicone resin particles ("KMP590" manufactured by Shin-Etsu Chemical Co., Ltd.).

[0111] (Preparation of sliding sheet (C4)) A sliding sheet (C4) was obtained in the same manner as the sliding sheet (1), except that, instead of the unmodified thermosetting silicone resin particles (manufactured by Shin-Etsu Chemical Co., Ltd., "KMP590"), acrylic-modified silicone resin particles (manufactured by Nissin Chemical Co., Ltd., "Chaline R200" (average particle size = 2 μm) were pulverized to 5 parts by mass of particles with an average particle size of 0.08 μm.

[0112] (Production of sliding sheet (C5): Using PTFE) A sliding sheet (C5) was obtained in the same manner as the sliding sheet (1), except that 10 parts by mass of polytetrafluoroethylene resin (PTFE) particles (Techno Chemical Co., Ltd.'s "Microdispers-3000", average particle size = 3 μm) were used instead of unmodified thermosetting silicone resin particles (Shin-Etsu Chemical Co., Ltd.'s "KMP590").

[0113] (Production of sliding sheet (C6): Glass cloth impregnated with fluororesin) A glass cloth was impregnated with a PTFE resin dispersion, dried at 150°C, baked at 380°C, and cooled to obtain a fluororesin (product name FGF400)-impregnated glass cloth sheet manufactured by Chukoh Chemical Industry Co., Ltd., which was used as the sliding sheet (C6).

[0114] <Lubricant> Lubricant (1): Dimethyl silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., product name "KF96") Lubricant (2): Amino-modified silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., product name "KF8009") Lubricant (3): Dimethyl silicone oil-containing silicone grease ("G503" manufactured by Shin-Etsu Chemical Co., Ltd.) Lubricant (C1): Fluoropolyether oil (Daikin Industries, Ltd. "Demnum S100") Lubricant (C2): PTFE grease containing fluoropolyether oil ("HP300" manufactured by Mitsui DuPont Fluorochemicals Co., Ltd.)

[0115] <Examples 1 to 7 and Comparative Examples 1 to 8> The pressure belt, sliding sheet, and lubricant in the combination shown in Table 1 were installed in the fixing device of an image forming apparatus "modified APEOS PORT Print C5570" manufactured by FUJIFILM Business Innovation Co., Ltd.

[0116] This apparatus was used as the image forming apparatus of each example, and the following evaluations were carried out.

[0117] <Evaluation> (Increased torque of pressure belt) The torque increase of the pressure belt was measured as follows. It is known that the torque required to drive the fixing roll is correlated with the current value of the motor that drives the fixing roll. Therefore, the motor current value was measured as a substitute characteristic for torque (unit: A). The increase in the current value of the fixing roll drive motor was evaluated as an increase in the torque of the pressure belt. If the drive torque increases too much, the drive gear of the fixing roll, which is the drive source, is burdened, causing practical problems, such as wrinkles on the paper on which the image is formed and abnormal gear noise. Here, it has been found that when the motor current value doubles to its initial value, the quality issue described above occurs. In this evaluation, 300,000 sheets were passed through, which is the lifespan of this fixing device, and if the motor current value was less than twice the normal value, it was judged to be no problem (denoted as "O"), and if it was more than twice the normal value, it was judged to be problematic (denoted as "X").

[0118] The results are shown in Table 1. The details of the abbreviations in Table 1 are as follows: PI: Polyimide resin PAI: Polyamide-imide resin, PEEK: Polyether ether ketone resin PPS: Polyphenylene sulfide resin PPSU: Polyphenylsulfone resin PEI: Polyetherimide resin PTFE: Polytetrafluoroethylene resin

[0119] KMP590: Unmodified thermosetting silicone resin particles ("KMP-590" manufactured by Shin-Etsu Chemical Co., Ltd., average particle size = 2 μm) R180S: Acrylic modified silicone particles ("Chaline R180S" manufactured by Nissin Chemical Industry Co., Ltd., average particle size = 30 μm) R200: Acrylic modified silicone particles ("Chaline R200" manufactured by Nissin Chemical Industry Co., Ltd., average particle size = 2 μm) Microdispers-3000: Polytetrafluoroethylene resin (PTFE) particles (Techno Chemical Co., Ltd. "Microdispers-3000", average particle size = 3 μm)

[0120] DSO: Dimethyl silicone oil ("KF96" manufactured by Shin-Etsu Chemical Co., Ltd.) ASO: Amino modified silicone oil ("KF8009" manufactured by Shin-Etsu Chemical Co., Ltd.) DSO-G: Dimethyl silicone oil-containing silicone grease (manufactured by Shin-Etsu Chemical Co., Ltd., product name "G503") FPEO: Fluoropolyether oil (Daikin Industries, Ltd. "Demnum S100") FPEO-PTFEG: PTFE grease containing fluoropolyether oil ("HP300" manufactured by Mitsui DuPont Fluorochemicals Co., Ltd.)

[0121] [Table 1]

[0122] From the above results, it is apparent that the present embodiment is superior in maintaining the sliding resistance of the sliding member as compared with the comparative example. Also, it can be seen that in this embodiment, the increase in the rotational torque of the pressure belt is suppressed compared to the comparative example.

[0123] The present embodiment includes the following aspects. (((1))) The sliding surface is configured to include a heat-resistant thermoplastic resin other than a fluororesin, and resin particles having a siloxane group other than the heat-resistant thermoplastic resin, The resin particles have an average particle size of 0.1 μm or more and 10 μm or less, The surface roughness Rsk of the sliding surface is 1.0 or less, the surface exposure rate of the resin particles on the sliding surface is 2% or more; Sliding member. (((2))) The sliding member according to (((1))), wherein the resin particles have an average particle size of 0.5 μm or more and 4 μm or less. (((3))) The sliding member according to (((1))) or (((2))), wherein the sliding surface has a surface roughness Rsk of 0.6 or less. (((4))) The sliding member according to any one of (((1))) to (((3))), wherein the surface exposure rate of the resin particles on the sliding surface is 3% or more. (((5))) ))) The sliding member according to any one of (((1))) to (((4))), wherein the heat-resistant thermoplastic resin is at least one resin selected from the group consisting of polyether ether ketone resins, polyphenylene sulfide resins, polyetherimide resins, and polyphenylsulfone resins. (((6))) The sliding member according to any one of ((1))) to (((5))), wherein the heat-resistant thermoplastic resin is at least one resin selected from the group consisting of polyether ether ketone resins and polyphenylene sulfide resins. (((7))) The sliding member according to any one of (((1))) to (((6))), wherein the resin particles are thermosetting silicone resin particles. (((8))) The sliding member according to (((7))), wherein the thermosetting silicone resin particles are modified thermosetting silicone resin particles. (((9))) The sliding member according to any one of (((1))) to (((8))), wherein the content of the resin particles is from 1.0% by mass to 20.0% by mass with respect to the heat-resistant thermoplastic resin. (((10))) The sliding member according to (((9))), wherein the content of the resin particles is 3% by mass or more and 25% by mass or less with respect to the heat-resistant thermoplastic resin. (((11))) The resin particles have an average particle size of 0.5 μm or more and 4 μm or less, The surface roughness Rsk of the sliding surface is 0.6 or less, The sliding member according to any one of (((1))) to (((10))), wherein the surface exposure rate of the resin particles on the sliding surface is 3% or more. (((12))) the heat-resistant thermoplastic resin is at least one resin selected from the group consisting of polyether ether ketone resin, polyphenylene sulfide resin, polyetherimide resin, and polyphenylsulfone resin; The content of the resin particles is 1.0% by mass or more and 20.0% by mass or less with respect to the heat-resistant thermoplastic resin, The sliding member according to any one of (((1))) to (((11))), wherein the resin particles are thermosetting silicone resin particles. (((13))) A first rotating body; a second rotor disposed in contact with the first rotor; a pressing member disposed on an inner circumferential surface of the second rotating body and pressing the second rotating body against the first rotating body from the inner circumferential surface of the second rotating body; a sliding member according to any one of (((1))) to (((12))) interposed between an inner circumferential surface of the second rotating body and the pressing member; a lubricant interposed between an inner circumferential surface of the second rotor and the sliding member; A fixing device comprising: (((14))) The fixing device according to (((13))), wherein the inner circumferential surface of the second rotating body is formed containing a resin having at least one type of group selected from the group consisting of an amide group, an imide group, a ketone group, and a sulfide group. (((15))) The fixing device according to (((13))) or (((14))), wherein the lubricant contains oil having a siloxane group as its main chain. (((16))) An image carrier; a latent image forming device for forming a latent image on a surface of an image carrier; a developing device for developing the latent image into a toner image using a developer; a transfer device for transferring the developed toner image onto a recording medium; The fixing device according to any one of (((13))) to (((15))) above, which fixes the toner image on the recording medium; An image forming apparatus comprising:

[0124] The advantages of the above aspect are as follows. According to the invention related to (((1))), it is possible to provide a slide member having excellent maintenance of sliding resistance compared to a slide member having a sliding surface including a glass cloth and a fluororesin impregnated into the glass cloth.

[0125] According to the invention related to (((2))), it is possible to provide a sliding member which is excellent in maintaining sliding resistance, as compared with a case in which the average particle size of the resin particles is less than 0.5 μm or exceeds 4 μm. According to the invention related to (((3))), it is possible to provide a sliding member which is excellent in maintaining sliding resistance, compared with a sliding surface having a surface roughness Rsk of more than 0.6. According to the invention related to (((4))), it is possible to provide a sliding member which is excellent in maintaining sliding resistance, compared to a case in which the surface exposure rate of the resin particles on the sliding surface is less than 3%.

[0126] According to the invention related to (((5))), it is possible to provide a sliding member which is excellent in maintaining sliding resistance, as compared with the case where the heat-resistant thermoplastic resin is a fluororesin. According to the invention related to (((6))), it is possible to provide a sliding member which is excellent in maintaining sliding resistance, as compared with the case where the heat-resistant thermoplastic resin is a polyphenylene sulfide resin.

[0127] According to the invention related to (((7))), it is possible to provide a sliding member which is excellent in maintaining sliding resistance, as compared with a case in which the resin particles are fluororesin particles. According to the invention related to (((8))), it is possible to provide a sliding member in which the thermosetting silicone resin particles are excellent in maintaining the sliding resistance compared to unmodified thermosetting silicone resin particles.

[0128] According to the invention related to (((9))), a sliding member having excellent retention of sliding resistance can be provided, compared to a case in which the content of resin particles is less than 1.0 mass % or more than 20.0 mass % relative to the heat-resistant thermoplastic resin. According to the invention related to (((10))), a sliding member having excellent retention of sliding resistance can be provided, compared to a case in which the content of resin particles is less than 3 mass % or more than 25 mass % relative to the heat-resistant thermoplastic resin.

[0129] According to the invention related to (((11))), it is possible to provide a sliding member which is excellent in maintaining sliding resistance, compared with a case in which the average particle size of the resin particles is less than 0.5 μm or exceeds 4 μm, a case in which the surface roughness Rsk of the sliding surface exceeds 0.6, or a case in which the surface exposure rate of the resin particles on the sliding surface is less than 3%. According to the invention related to (((12))), it is possible to provide a sliding member which is excellent in maintaining sliding resistance, compared with a case in which the heat-resistant thermoplastic resin is a fluororesin, a case in which the resin particles are fluororesin particles, or a case in which the content of the resin particles is less than 1.0 mass % or more than 20.0 mass % relative to the heat-resistant thermoplastic resin.

[0130] According to the invention pertaining to (((13))), there is provided a fixing device which can suppress an increase in the rotation torque of the second rotating body and form an image with reduced gloss unevenness, as compared to the case where a sliding member having a sliding surface containing glass cloth and a fluororesin impregnated into the glass cloth is used. According to the invention pertaining to (((14))), there is provided a fixing device which can suppress an increase in the rotational torque of the second rotating body and form an image with reduced gloss unevenness, compared to when the inner surface of the second rotating body is made of polyimide resin. According to the invention (((15))), there is provided a fixing device which can suppress an increase in the rotational torque of the second rotating body and form an image with reduced gloss unevenness, compared to a case in which the lubricant is composed only of fluoropolyether oil.

[0131] According to the invention pertaining to (((16))), there is provided an image forming apparatus which can suppress an increase in the rotation torque of the second rotating body of the fixing device and form an image with reduced gloss unevenness, as compared to the case where a sliding member having a sliding surface comprising glass cloth and a fluororesin impregnated into the glass cloth is used. [Explanation of symbols]

[0132] 1Y, 1M, 1C, 1K photoconductor 2Y, 2M, 2C, 2K Charging roller 3Y, 3M, 3C, 3K laser beam 3. Exposure equipment 4Y, 4M, 4C, 4K developing device 5Y, 5M, 5C, 5K Primary transfer roller 6Y, 6M, 6C, 6K Photoconductor Cleaning Device 10Y, 10M, 10C, 10K process cartridges 20 Intermediate transfer belt 20a Intermediate transfer body cleaning device 22 Drive roller 24 Support roller 26 Secondary transfer roller 28 Fixing device 30 Heating Roll 40 Pressure Belt 50 Pressure Pad 52 Belt guide 60 Sliding Sheet 62 Lubricants 64 Lubricant supply member 100 Image forming device P Recording medium

Claims

1. The sliding surface is configured to include a heat-resistant thermoplastic resin other than a fluororesin, and resin particles having a siloxane group other than the heat-resistant thermoplastic resin, The resin particles have an average particle size of 0.1 μm or more and 10 μm or less, The surface roughness Rsk of the sliding surface is 1.0 or less, a surface exposure rate of the resin particles on the sliding surface is 2% or more; Sliding member.

2. 2. The sliding member according to claim 1, wherein the resin particles have an average particle size of 0.5 μm or more and 4 μm or less.

3. 2. The sliding member according to claim 1, wherein the surface roughness Rsk of the sliding surface is 0.6 or less.

4. 2. The sliding member according to claim 1, wherein the resin particles are exposed on the sliding surface at a rate of 3% or more.

5. 2. The sliding member according to claim 1, wherein the heat-resistant thermoplastic resin is at least one resin selected from the group consisting of polyether ether ketone resins, polyphenylene sulfide resins, polyetherimide resins, and polyphenylsulfone resins.

6. 2. The sliding member according to claim 1, wherein the heat-resistant thermoplastic resin is at least one resin selected from the group consisting of polyether ether ketone resins and polyphenylene sulfide resins.

7. 2. The sliding member according to claim 1, wherein the resin particles are thermosetting silicone resin particles.

8. 8. The sliding member according to claim 7, wherein the thermosetting silicone resin particles are modified thermosetting silicone resin particles.

9. 2. The sliding member according to claim 1, wherein the content of the resin particles is 1.0% by mass or more and 20.0% by mass or less with respect to the heat-resistant thermoplastic resin.

10. 10. The sliding member according to claim 9, wherein the content of the resin particles is 3% by mass or more and 25% by mass or less with respect to the heat-resistant thermoplastic resin.

11. The resin particles have an average particle size of 0.5 μm or more and 4 μm or less, The surface roughness Rsk of the sliding surface is 0.6 or less, 2. The sliding member according to claim 1, wherein the resin particles are exposed on the sliding surface at a rate of 3% or more.

12. the heat-resistant thermoplastic resin is at least one resin selected from the group consisting of polyether ether ketone resin, polyphenylene sulfide resin, polyetherimide resin, and polyphenylsulfone resin; The content of the resin particles is 1.0% by mass or more and 20.0% by mass or less with respect to the heat-resistant thermoplastic resin, 2. The sliding member according to claim 1, wherein the resin particles are thermosetting silicone resin particles.

13. A first rotating body; a second rotor disposed in contact with the first rotor; a pressing member disposed on an inner circumferential surface of the second rotating body and pressing the second rotating body against the first rotating body from the inner circumferential surface of the second rotating body; The sliding member according to any one of claims 1 to 12, which is interposed between an inner circumferential surface of the second rotating body and the pressing member; a lubricant interposed between an inner circumferential surface of the second rotor and the sliding member; A fixing device comprising:

14. 14. The fixing device according to claim 13, wherein the inner circumferential surface of the second rotating member is formed containing a resin having at least one type of group selected from the group consisting of an amide group, an imide group, a ketone group, and a sulfide group.

15. The fixing device according to claim 13 , wherein the lubricant contains oil having a siloxane group as a main chain.

16. An image carrier; a latent image forming device for forming a latent image on a surface of an image carrier; a developing device for developing the latent image into a toner image using a developer; a transfer device for transferring the developed toner image onto a recording medium; The fixing device according to claim 13 , which fixes the toner image on the recording medium; An image forming apparatus comprising:

Images