Fixing device and image forming apparatus

Abstract

The invention discloses a fixing device and an image forming apparatus. The fixing device includes: a first rotating body; a second rotating body which is disposed so as to be in contact with the first rotating body; a pressing member that is disposed on the inner circumferential surface of the second rotating body and presses the second rotating body from the inner circumferential surface of the second rotating body toward the first rotating body; a sliding member interposed between an inner circumferential surface of the second rotating body and the pressing member; and a lubricant interposed between the inner peripheral surface of the second rotating body and the sliding member, the sliding surface of the sliding member having irregularities, a surface roughness (Ra1) of 0.20 [mu] m or more, and a load length ratio (Rmr) of 35% or more.

Description

Technical Field

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

[0002] For example, Japanese Unexamined Patent Application Publication No. 2005-091557 discloses "a sliding member for an electrophotographic apparatus having irregularities on its surface and interposing a lubricant between the surfaces in contact therewith, characterized in that at least the ten-point mean roughness Rz in the sliding direction of the surface is larger than the ten-point mean surface roughness Rz in the direction perpendicular to the sliding direction."

[0003] In addition, Japanese Unexamined Patent Application Publication No. 2022-184460 discloses "a belt device including: a rotatable annular belt; a sliding member that relatively slides on the inner peripheral surface of the belt; a pressing member that contacts the sliding member with the belt interposed therebetween and forms an engagement portion with the belt; and a lubricant interposed between the inner peripheral surface of the belt and the sliding member, characterized in that in the respective sliding surfaces where the belt and the sliding member slide, the elastic power of the sliding surface of the belt is 55% or more, and the surface roughness of the sliding surface of the sliding member is larger than the surface roughness of the sliding surface of the belt." Summary of the Invention

[0004] Currently, there is known a fixing device (hereinafter, also referred to as a specific fixing device) including: a first rotating body; a second rotating body disposed in contact with the first rotating body; a pressing member disposed on the inner peripheral surface of the second rotating body and pressing the second rotating body against the first rotating body from the inner peripheral surface of the second rotating body; a sliding member interposed between the inner peripheral surface of the second rotating body and the pressing member; and a lubricant interposed between the inner peripheral surface of the second rotating body and the sliding member.

[0005] An object of the present invention is to provide a fixing device that can reduce damage to the inner peripheral surface of a fixing member (i.e., the second rotating body) as compared with a case where the surface roughness Ra1 of the sliding surface of the sliding member in a specific fixing device is less than 0.20 μm or the load length ratio Rmr of the sliding surface of the sliding member is less than 35%.

[0006] According to a first aspect of the present invention, a fixing device can be provided, which includes: a first rotating body; a second rotating body disposed in contact with the first rotating body; a pressing member disposed 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. The sliding surface of the sliding member has irregularities, the surface roughness Ra1 is 0.20 μm or more, and the load length ratio Rmr is 35% or more.

[0007] According to a second aspect of the present invention, in the fixing device based on the first aspect, the surface roughness Ra1 is 0.20 μm or more and 5.00 μm or less.

[0008] According to a third aspect of the present invention, in the fixing device based on the first or second aspect, the load length ratio Rmr is 36% or more and 75% or less.

[0009] According to a fourth aspect of the present invention, in the fixing device based on any one of the first to third aspects, the sliding member has a planar heating element.

[0010] According to a fifth aspect of the present invention, in the fixing device based on the fourth aspect, the sliding member has a glass layer on the sliding surface.

[0011] According to a sixth aspect of the present invention, in the fixing device based on any one of the first to fifth aspects, the surface roughness Ra1 of the sliding surface of the sliding member is a value smaller than the surface roughness Ra2 of the inner circumferential surface of the second rotating body.

[0012] According to a seventh aspect of the present invention, in the fixing device based on the sixth aspect, the difference (Ra2 - Ra1) between the surface roughness Ra1 of the sliding surface of the sliding member and the surface roughness Ra2 of the inner circumferential surface of the second rotating body is 0.05 μm or more and 2.00 μm or less.

[0013] According to an eighth aspect of the present invention, in the fixing device based on any one of the first to seventh aspects, the hardness A of the sliding surface of the sliding member is a value higher than the hardness B of the inner circumferential surface of the second rotating body.

[0014] According to a ninth aspect of the present invention, in the fixing device based on the eighth aspect, the difference (A - B) between the hardness A of the sliding surface of the sliding member and the hardness B of the inner circumferential surface of the second rotating body is 10 or more and 600 or less.

[0015] According to the tenth aspect of the present invention, in the fixing device according to any one of the first to ninth aspects, the viscosity of the lubricant is 20 mm 2 / s or more and 1000 mm 2 / s or less.

[0016] According to the eleventh aspect of the present invention, an image forming apparatus can be provided, which includes: an image holding member; a latent image forming device that forms a latent image on the surface of the image holding member; a developing device that develops the latent image into a toner image using a developer; a transfer device that transfers the developed toner image onto a recording medium; and the fixing device according to any one of the first to tenth aspects, which fixes the toner image on the recording medium.

[0017] (Effect)

[0018] According to the first aspect, a fixing device can be provided, which can reduce damage to the inner peripheral surface of the fixing member as compared with a case where, in a specific fixing device, the surface roughness Ra1 of the sliding surface of the sliding member is less than 0.20 μm, or the load length ratio Rmr of the sliding surface of the sliding member is less than 35%.

[0019] According to the second aspect, a fixing device can be provided, which can reduce damage to the inner peripheral surface of the fixing member as compared with a case where, in a specific fixing device, the surface roughness Ra1 is less than 0.20 μm or exceeds 5.00 μm.

[0020] According to the third aspect, a fixing device can be provided, which can reduce damage to the inner peripheral surface of the fixing member as compared with a case where, in a specific fixing device, the load length ratio Rmr is less than 36% or exceeds 75%.

[0021] According to the fourth aspect, a fixing device can be provided, which can reduce damage to the inner peripheral surface of the fixing member as compared with a case where, in a specific fixing device, the sliding member is a pressing member without a heater.

[0022] According to the fifth aspect, a fixing device can be provided, which can reduce damage to the inner peripheral surface of the fixing member as compared with a case where, in a specific fixing device, the sliding member does not have a glass layer on the sliding surface.

[0023] According to the sixth aspect, a fixing device can be provided, which can reduce damage to the inner peripheral surface of the fixing member as compared with a case where, in a specific fixing device, the surface roughness Ra1 of the sliding surface of the sliding member is a value larger than the surface roughness Ra2 of the inner peripheral surface of the second rotating body.

[0024] According to the seventh aspect, a fixing device can be provided which can reduce damage to the inner peripheral surface of a fixing member as compared with a case where, in a specific fixing device, the difference (Ra2 - Ra1) between the surface roughness Ra1 of the sliding surface of a sliding member and the surface roughness Ra2 of the inner peripheral surface of a second rotating body is less than 0.05 μm or more than 2.00 μm.

[0025] According to the eighth aspect, a fixing device can be provided which can reduce damage to the inner peripheral surface of a fixing member as compared with a case where, in a specific fixing device, the hardness A of the sliding surface of a sliding member is lower than the hardness B of the inner peripheral surface of a second rotating body.

[0026] According to the ninth aspect, a fixing device can be provided which can reduce damage to the inner peripheral surface of a fixing member as compared with a case where, in a specific fixing device, the difference (A - B) between the hardness A of the sliding surface of a sliding member and the hardness B of the inner peripheral surface of a second rotating body is less than 10 or more than 600.

[0027] According to the tenth aspect, a fixing device can be provided which can reduce damage to the inner peripheral surface of a fixing member as compared with a case where, in a specific fixing device, the viscosity of a lubricant is lower than 20 mm 2 / s or higher than 1000 mm 2 / s.

[0028] According to the eleventh aspect, an image forming device can be provided which can reduce damage to the inner peripheral surface of a fixing member as compared with an image forming device of a fixing device having a sliding surface roughness Ra1 of a sliding member lower than 0.20 μm or a load length ratio Rmr of the sliding surface of the sliding member lower than 35%. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 is a schematic diagram showing an example of the image forming device of the present embodiment;

[0030] Figure 2 is a schematic diagram showing an example of the fixing device of the present embodiment;

[0031] Figure 3 is a top view showing an example of the surface heating element 64 of the fixing device of the present embodiment;

[0032] Figure 4 is a schematic diagram regarding the method for obtaining the load length ratio Rmr. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] Hereinafter, an embodiment as an example of the present invention will be described. These descriptions and examples are illustrative of the embodiments and do not limit the scope of the disclosure.

[0034] In the numerical ranges described stepwise in this specification, the upper limit value or the lower limit value described in one numerical range may also be replaced with the upper limit value or the lower limit value of another numerically described stepwise range. Further, in the numerical ranges described in this specification, the upper limit value or the lower limit value of the numerical range may also be replaced with the value shown in the examples.

[0035] Each component may also contain a plurality of corresponding substances.

[0036] When referring to the amounts of the respective components in the composition, in the case where there are a plurality of substances corresponding to each component in the composition, unless otherwise specified, it means the total amount of the plurality of substances present in the composition.

[0037] When describing the embodiments with reference to the drawings, components having substantially the same function are denoted by the same reference numerals throughout the drawings, and repeated descriptions may sometimes be omitted.

[0038] <Fixing device / Image forming device>

[0039] The fixing device of the present embodiment includes: a first rotating body; a second rotating body disposed in contact with the first rotating body; a pressing member disposed on the inner peripheral surface of the second rotating body for pressing the second rotating body against the first rotating body from the inner peripheral surface of the second rotating body; a sliding member interposed between the inner peripheral surface of the second rotating body and the pressing member; and a lubricant interposed between the inner peripheral surface of the second rotating body and the sliding member, wherein the sliding surface of the sliding member has irregularities, the surface roughness Ra1 is 0.20 μm or more, and the load length ratio Rmr is 35% or more.

[0040] The image forming device of the present embodiment includes:

[0041] An image holding body;

[0042] A latent image forming device that forms a latent image on the surface of the image holding body;

[0043] A developing device that develops the latent image into a toner image using a developer;

[0044] A transfer device that transfers the developed toner image onto a recording medium; and

[0045] A fixing device that fixes the toner image on the recording medium.

[0046] Moreover, the image forming device of the present embodiment applies the fixing device of the above-described present embodiment.

[0047] With the above structure, the fixing device and the image forming apparatus according to the present embodiment can reduce the damage to the inner peripheral surface of the fixing member. The reason is presumably as follows.

[0048] Conventionally, when forming an image in an electrophotographic image forming apparatus such as a printer, a copier, or a fax machine, after transferring the toner image onto a recording medium such as a recording paper, the fixing device heats and presses the recording medium onto which the toner image has been transferred, thereby fixing the toner image on the surface of the recording medium.

[0049] Conventionally, as such a fixing device, various types of devices have been proposed, and among them, the above-described specific fixing device is known.

[0050] In a conventional specific fixing device, from the viewpoint of maintaining a lubricant between the inner peripheral surface of the second rotating body and the sliding surface of the sliding member, a sliding member having irregularities on the sliding surface has been proposed. However, in the conventional sliding member, due to the irregular shape of its sliding surface, damage tends to occur on the inner peripheral surface of the second rotating body (for example, a fixing belt such as a pressure belt) during sliding. Therefore, in the region where such local damage occurs, it is difficult to maintain the lubricant and the sliding member and the second rotating body come into direct contact, so an increase in rotational torque or wear of the second rotating body tends to occur.

[0051] In contrast, in the fixing device according to the present embodiment, the sliding surface of the sliding member has irregularities, the surface roughness Ra1 is 0.20 μm or more, and the load length ratio Rmr is 35% or more.

[0052] Here, the load length ratio Rmr will be described with reference to the drawings. Figure 4 It is a schematic diagram of the method for obtaining the load length ratio Rmr. As Figure 4 shown, first, for the sliding surface of the sliding member, a roughness curve in the axial direction is obtained, and a reference length L is extracted in the direction of the average line of the roughness curve. Then, the roughness curve of the extracted portion is cut with a cut-off level c (%) parallel to the peak line, and the ratio of the sum of the cut-off lengths (load length ηp = b1 + b2 +... + bn) obtained at this time to the reference length L expressed as a percentage is the load length ratio Rmr (= ηp / L × 100). In addition, the cut-off level c when obtaining the load length ratio Rmr is a value expressed as a percentage of the ratio of the distance between the peak line and the valley line of the extracted portion, that is, the maximum height Ry, and is a value when the highest peak is set to 0% and the lowest valley is set to 100%.

[0053] As described above, the load length ratio Rmr represents the smoothness of the convex portions on the sliding surface of the sliding member. Thus, when the load length ratio Rmr is 35% or more and the surface roughness Ra1 is 0.20 μm or more, it means that the sliding surface of the sliding member that abuts against the inner circumferential surface of the second rotating body has irregularities. On the other hand, the front ends of the convex portions are blunted, that is, moderately smoothed. Therefore, damage to the inner circumferential surface of the second rotating body is also reduced during sliding. As a result, it is considered that the lubricant interposed between the inner circumferential surface of the second rotating body and the sliding member is easily retained, suppressing an increase in rotational torque or wear of the inner circumferential surface of the second rotating body.

[0054] Hereinafter, an example of the image forming apparatus according to the present embodiment will be described with reference to the drawings.

[0055] Figure 1 FIG. is a schematic diagram showing an example of the image forming apparatus according to the present embodiment.

[0056] Figure 2 FIG. is a schematic diagram showing an example of the fixing device according to the present embodiment.

[0057] Figure 3 FIG. is a plan view showing an example of the surface heating element 64 of the fixing device according to the present embodiment.

[0058] (Structure of the image forming apparatus)

[0059] As Figure 1 shown, the image forming apparatus 100 according to the present embodiment includes first to fourth processing cartridges 10Y, 10M, 10C, 10K (an example of an image forming unit) of the electrophotographic method, which respectively output images of yellow (Y), magenta (M), cyan (C), and black (K) colors based on color-separated image data. These processing cartridges 10Y, 10M, 10C, 10K are arranged side by side separately along the outer circumferential surface of the intermediate transfer belt 20. In addition, these processing cartridges 10Y, 10M, 10C, 10K are detachable from the image forming apparatus main body.

[0060] Above each of the processing cartridges 10Y, 10M, 10C, 10K ( Figure 1 inside), an intermediate transfer belt 20 serving as an intermediate transfer member is provided, and the intermediate transfer belt 20 is arranged such that its outer circumferential surface faces each processing cartridge. The intermediate transfer belt 20 is wound around a driving roller 22 and a support roller 24 that are separately arranged, and is provided with tension, and travels annularly in the direction from the first processing cartridge 10Y toward the fourth processing cartridge 10K, and the support roller 24 is in contact with the inner circumferential surface of the intermediate transfer belt 20.

[0061] In addition, the support roller 24 is pressed away from the driving roller 22 by an elastic member such as a spring (not shown), and tension is applied to the intermediate transfer belt 20 wound between the two. Further, on the outer peripheral surface of the intermediate transfer belt 20, an intermediate transfer body cleaning device 20a is provided opposite to the driving roller 22.

[0062] The first to fourth processing cartridges 10Y, 10M, 10C, and 10K have substantially the same structure. Therefore, the first processing cartridge 10Y will be described as a representative here. The first processing cartridge 10Y is disposed on the upstream side in the traveling direction of the intermediate transfer belt and forms a yellow image. In addition, for the parts that are the same as those of the first processing cartridge 10Y, the same reference signs of magenta (M), cyan (C), and black (K) are marked instead of yellow (Y), thereby omitting the description of the second to fourth processing cartridges 10M, 10C, and 10K.

[0063] The first processing cartridge 10Y has a photoreceptor 1Y that functions as an image holding body. Around the photoreceptor 1Y, a charging roller (an example of a charging device) 2Y that charges the surface of the photoreceptor 1Y to a predetermined potential, a developing device 4Y that supplies charged toner contained in the developer to the electrostatic latent image to develop the electrostatic latent image, and a photoreceptor cleaning device 6Y that removes the toner remaining on the surface of the photoreceptor 1Y after primary transfer are sequentially arranged. They are integrally formed within a housing 11Y (frame). Similarly, for the second to fourth processing cartridges 10M to 10K, each component is integrally formed within a housing 11M to 11K (frame).

[0064] Moreover, together with the first processing 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 with laser light 3Y based on the color-separated image signal to form an electrostatic latent image are arranged, thereby constituting an image forming unit.

[0065] In addition, the charging roller 2Y and the exposure device 3 are examples of a latent image forming device.

[0066] In addition, the primary transfer roller 5Y is disposed inside the intermediate transfer belt 20 and is provided at a position opposite to the photoreceptor 1Y. Moreover, a bias power source (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 source can change the transfer bias applied to each primary transfer roller under the control of a control unit (not shown).

[0067] (Structure of the fixing device)

[0068] As Figure 2As shown, the fixing device 60 includes a cylindrical pressure roller 52 (an example of a first rotating body), a pressure belt 62 (an example of a second rotating body), and a planar heating element 64 (an example of a sliding member) that extend in the depth direction of the device. The fixing device 60 further includes a pressing member 68 that holds the planar heating element 64 and a frame member 72 that supports the pressing member 68.

[0069] The planar heating element 64 generates heat for heating. The planar heating element 64 is disposed inside the pressure belt 62 and on the side opposite to the pressure roller 52 with the pressure belt 62 interposed therebetween. The planar heating element 64 is a plate-shaped member with its plate surface facing the width direction of the device, and extends from one end in the depth direction of the pressure belt 62 to the other end.

[0070] As Figure 3 shown, when viewed from the plate thickness direction, the planar heating element 64 is rectangular and extends in the depth direction of the device. The planar heating element 64 has an electrically insulating base material 64A, an insulating layer 64B formed of a heat-resistant resin material, and a pair of electrodes 64C for applying voltage. The planar heating element 64 further has a plurality of resistance heating portions 64D that generate heat by applying voltage to the electrodes 64C, and a pair of connection portions 64E that electrically connect both ends of each of the electrodes 64C and the resistance heating portions 64D. Moreover, the electrodes 64C, the resistance heating portions 64D, and the connection portions 64E are formed on the base material 64A, and the resistance heating portions 64D and the connection portions 64E are covered with the insulating layer 64B from the opposite side of the base material 64A.

[0071] Next, the operation of the fixing device 60 will be described.

[0072] When fixing the toner image transferred onto the sheet member P onto the sheet member P, the pressure roller 52 is transmitted a rotational force from a motor (not shown) and rotates in the direction of arrow R1 as Figure 2 shown. As a result, the pressure belt 62 in contact with the pressure roller 52 circulates in the direction of arrow R2 following the rotation of the pressure roller 52 while sliding on the planar heating element 64. A lubricant S is held between the inner peripheral surface 90 of the pressure belt 62 and the planar heating element 64. Through this lubricant S, an increase in the sliding resistance generated between the pressure belt 62 and the planar heating element 64 is suppressed.

[0073] · Surface roughness Ra

[0074] The surface roughness Ra1 of the sliding surface of the sliding member is 0.20 μm or more, preferably 0.20 μm or more and 5.00 μm or less, more preferably 0.20 μm or more and 2.00 μm or less, and further preferably 0.20 μm or more and 1.00 μm or less.

[0075] If the surface roughness Ra1 is below the upper limit value, damage to the inner peripheral surface of the second rotating body caused by the unevenness on the sliding surface of the sliding member can be suppressed. If the surface roughness Ra1 is above the lower limit value, it is easier to appropriately retain the lubricant between the sliding member and the second rotating body.

[0076] The method for making the surface roughness Ra1 of the sliding surface of the sliding member within the above range is not particularly limited. For example, there can be mentioned: a method of making the sliding surface of the sliding member a glass layer and grinding the surface of the glass layer into a convex shape with sandpaper having a specified particle size (for example, 0.05 μm or more and 0.15 μm or less); a method of making the sliding surface of the sliding member a glass layer and setting the firing temperature after forming the glass layer to 550 °C or more and 1000 °C or less (more preferably 700 °C or more and 900 °C or less), etc.

[0077] The surface roughness Ra2 of the inner peripheral surface of the second rotating body is preferably 0.20 μm or more and 3.00 μm or less, more preferably 0.25 μm or more and 2.00 μm or less, and still more preferably 0.30 μm or more and 1.00 μm or less.

[0078] If the surface roughness Ra2 of the inner peripheral surface of the second rotating body is below the upper limit value, the discharge of the lubricant between the inner peripheral surface of the second rotating body and the sliding member from the uneven portions on the inner peripheral surface of the second rotating body can be further suppressed. If the surface roughness Ra2 of the inner peripheral surface of the second rotating body is above the lower limit value, it is easier to appropriately retain the lubricant between the sliding member and the second rotating body.

[0079] The method for making the surface roughness Ra2 of the inner peripheral surface of the second rotating body within the above range is not particularly limited. For example, there can be mentioned: a method of performing uneven processing on the inner peripheral surface (for example, the pressure belt) of the second rotating body by shot peening or the like (more preferably, adjusting the shot peening time per unit area, the bead diameter, etc. in shot peening), etc.

[0080] The surface roughness Ra1 and the surface roughness Ra2 are obtained by the following operations.

[0081] A part of the surface layer of the sliding surface of the sliding member or the inner peripheral surface of the second rotating body is cut off with a cutter or the like to obtain a measurement specimen. This measurement specimen is measured using a stylus type surface roughness measuring machine (such as SURFCOM 1400A: manufactured by Tokyo Seimitsu (ACCRETECH) Co., Ltd., etc.). As its measurement conditions, in accordance with JIS B0601 - 1994, the evaluation length Ln = 2.5 mm, the reference length L = 0.8 mm, and the cutoff value = 0.008 mm are set.

[0082] The surface roughness Ra1 of the sliding surface of the sliding member is preferably smaller than the surface roughness Ra2 of the inner peripheral surface of the second rotating body.

[0083] When the surface roughness Ra1 is smaller than the surface roughness Ra2, the unevenness of the sliding surface of the sliding member is smaller than that of the inner peripheral surface of the second rotating body. Therefore, when the sliding member abuts against and slides on the second rotating body, damage to the inner peripheral surface of the second rotating body is further suppressed.

[0084] The difference (Ra2 - Ra1) between the surface roughness Ra1 of the sliding surface of the sliding member and the surface roughness Ra2 of the inner peripheral surface of the second rotating body is preferably 0.05 μm or more and 2.00 μm or less, more preferably 0.07 μm or more and 1.00 μm or less, and further preferably 0.08 μm or more and 0.60 μm or less. If the above difference is below the upper limit value, damage to the inner peripheral surface of the pressure belt 62 caused by the convex portions in the unevenness of the sliding surface of the sliding member is further suppressed. If the above difference is above the lower limit value, the unevenness of the sliding surface of the sliding member can be appropriately maintained, and it is easier to maintain the lubricant between the pressure belt 62 and the sliding member. As a result, damage to the inner peripheral surface of the pressure belt 62 is further suppressed.

[0085] · Load length ratio Rmr

[0086] The load length ratio Rmr of the sliding surface of the sliding member is 35% or more, preferably 36% or more and 75% or less, more preferably 37% or more and 70% or less, and further preferably 38% or more and 65% or less. In addition, these values are the values when the cut-off level is 10%. If the load length ratio Rmr is above the lower limit value, damage to the inner peripheral surface of the pressure belt 62 caused by the convex portions in the unevenness of the sliding surface of the sliding member is further suppressed. If the load length ratio Rmr is below the upper limit value, the unevenness of the sliding surface of the sliding member can be appropriately maintained, and it is easier to maintain the lubricant between the pressure belt 62 and the sliding member. As a result, damage to the inner peripheral surface of the pressure belt 62 is further suppressed.

[0087] The load length ratio Rmr (c%) of the sliding surface of the sliding member (where c represents the cut-off level (%)) is a value measured by the above operation according to JIS B 0601 - 1994.

[0088] The method for setting the load length ratio Rmr of the sliding surface of the sliding member within the above range is not particularly limited. For example, it may include: a method of setting the sliding surface of the sliding member as a glass layer and grinding the surface of the glass layer into a convex shape with sandpaper having a specified particle size (e.g., 0.05 μm or more and 0.15 μm or less); a method of setting the sliding surface of the sliding member as a glass layer and setting the firing temperature after forming the glass layer to 550°C or more and 1000°C or less (more preferably 700°C or more and 900°C or less), etc.

[0089] · Hardness

[0090] The hardness A of the sliding surface of the sliding member is preferably higher than the hardness B of the inner peripheral surface of the second rotating body. Thereby, it further suppresses damage to the inner peripheral surface of the pressure belt 62 due to the sliding surface of the sliding member being too hard.

[0091] The difference (A - B) between the hardness A of the sliding surface of the sliding member and the hardness B of the inner peripheral surface of the second rotating body is preferably 10 or more and 600 or less, more preferably 10 or more and 500 or less, and still more preferably 50 or more and 100 or less. Thereby, it further suppresses damage to the inner peripheral surface of the pressure belt 62 due to the sliding surface of the sliding member being too hard.

[0092] The hardness A of the sliding surface of the sliding member is preferably 100 or more and 600 or less, more preferably 500 or more and 600 or less. If the hardness A of the sliding surface of the sliding member is below the upper limit value, it further suppresses damage to the inner peripheral surface of the pressure belt 62 due to the material of the sliding member being too hard. On the other hand, when the hardness A of the sliding surface of the sliding member is above the lower limit value, it is easier to maintain the lubricant between the sliding member and the inner peripheral surface of the pressure belt 62.

[0093] The method for setting the hardness A of the sliding surface of the sliding member within the above range is not particularly limited. For example, it may include: a method of setting the sliding surface of the sliding member as a glass layer, etc.

[0094] The hardness B of the inner peripheral surface of the second rotating body is preferably 70 or more and 500 or less, more preferably 100 or more and 400 or less. If the hardness B of the inner peripheral surface of the second rotating body is within the above range, excessive friction will not occur when the sliding member slides with the second rotating body, and damage to the inner peripheral surface of the second rotating body can be further reduced.

[0095] The method for setting the hardness B of the inner peripheral surface of the second rotating body within the above range is not particularly limited. For example, it may include: a method of setting the inner peripheral surface of the second rotating body as a resin layer or a plating layer, a method of adding ceramic or carbon-based fillers, etc.

[0096] The hardness of the sliding surface of the sliding member and the inner peripheral surface of the second rotating body is Vickers hardness, which is measured by the following method. Using a microhardness tester (MVK-HVL, manufactured by Akashi Seisakusho), a indenter is pressed into the surface of the object to be measured, and the Vickers hardness Hv is measured under the conditions of an indentation load of 10 gf and an indentation time of 20 s. The surface of the object to be measured is cut, and the measurement is performed at a depth of 20 μm from the surface. Then, this operation is carried out at five places, and the average value is taken as the Vickers hardness Hv.

[0097] - Pressing roller 52 (an example of the first rotating body)-

[0098] The pressing roller 52 includes, for example, a metal shaft portion 54 having a heat source such as a halogen lamp inside and extending in the depth direction of the apparatus, a cylindrical elastic body layer 56 through which the shaft portion 54 passes, and a release layer 58 covering the elastic body layer 56.

[0099] The shaft portion 54 is constituted by, for example, a cylindrical body made of a metal such as aluminum or stainless steel.

[0100] The elastic body layer 56 is constituted by, for example, HTV silicone rubber or fluororubber (rubber hardness of about 45 degrees in JIS-A, and the rubber hardness is measured by a spring-type A hardness tester manufactured by Teclock Corporation according to JIS K6301 with an additional load of 1,000 gf) with a thickness of about 2 mm or more and 5 mm or less.

[0101] The release layer 58 is constituted by, for example, fluororubber, silicone rubber, fluororesin, silicone resin, etc. with a thickness of 20 μm or more and 50 μm or less. Of course, it is not limited thereto, and it may also be constituted by conventionally known materials.

[0102] The pressing roller 52 functions as a fixing roller, and its speed is adjusted by a drive source (not shown). For example, it is rotationally driven at a peripheral speed of 260 mm / sec. The outer diameter of the pressing roller 52 is generally, for example, 25 mm or more and 80 mm or less.

[0103] The surface temperature of the pressing roller 52 is detected by a temperature sensor (not shown) in contact with the surface, and the surface temperature is controlled by a control circuit (not shown) to reach, for example, 175°C.

[0104] - Pressing belt 62 (an example of the second rotating body)-

[0105] The pressing belt 62 is constituted by at least including a resin. This resin is a heat-resistant resin. In addition, "heat resistance" means the property of not melting or decomposing even when reaching the temperature rise temperature (for example, the fixing temperature) of the fixing device. The same applies hereinafter.

[0106] The pressure band 62 can be a single-layer body of a resin base material layer, or a laminate having a resin base material layer, an elastic layer provided on the resin base material layer, and a release layer provided on the elastic layer; or a laminate having a resin base material layer and a release layer provided on the resin base material layer. The resin base material layer may also contain a conductive material other than the resin as needed.

[0107] Examples of the resin contained in the resin base material layer include: polyimide resin, polyamideimide resin, polyetheretherketone resin, polyphenylene sulfide resin, polyethersulfone resin, polysulfone resin, polyarylene sulfone resin, etc. The resin can be a single type or two or more types can be used in combination. Among them, as the resin, it is more preferably a polyimide resin-containing resin.

[0108] Examples of the polyimide resin include: an imide compound of a copolymer of tetracarboxylic dianhydride and a diamine compound, namely polyamic acid (a precursor of the polyimide resin).

[0109] Examples of the polyimide resin include: a resin having a structural unit represented by the following general formula (I).

[0110]

[0111] In the general formula (I), R 1 represents a tetravalent organic group, and R 2 represents a divalent organic group.

[0112] Examples of the tetravalent organic group represented by R 1 include: an aromatic group, an aliphatic group, a cycloaliphatic group, a group combining an aromatic group and an aliphatic group, or a substituted group thereof. Specifically, examples of the tetravalent organic group include: the residue of the tetracarboxylic dianhydride described later.

[0113] Examples of the divalent organic group represented by R 2 include: an aromatic group, an aliphatic group, a cycloaliphatic group, a group combining an aromatic group and an aliphatic group, or a substituted group thereof. Specifically, examples of the divalent organic group include: the residue of the diamine compound described later.

[0114] Examples of the tetracarboxylic dianhydrides used as raw materials for polyimide resins include, specifically: pyromellitic dianhydride, 3,3',4,4'-benzophenone tetracarboxylic dianhydride, 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, ethylenetetracarboxylic dianhydride, etc.

[0115] Specific examples of the 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-naphthalenediamine, m-phenylenediamine, p-phenylenediamine, 3,3'-dimethyl-4,4'-diaminobiphenyl, benzidine, 3,3'-dimethylbenzidine, 3,3'-dimethoxybenzidine, 4,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl propane, 2,4-bis(β-aminotert-butyl)toluene, bis(p-β-aminotert-butylphenyl)ether, bis(p-β-methyl-δ-aminophenyl)benzene, bis-p-(1,1-dimethyl-5-aminopentyl)benzene, 1-isopropyl-2,4-m-phenylenediamine, m-xylylenediamine, p-xylylenediamine, bis(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, 3-methylheptamethylenediamine, 5-methylnonamethylenediamine, 2,17-diaminoeicosadecane, 1,4-diaminocyclohexane, 1,10-diamino-1,10-dimethyldecane, 1,2-diaminooctadecane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, piperazine, H2N(CH2)3O(CH2)2O(CH2)NH2, H2N(CH2)3S(CH2)3NH2, H2N(CH2)3N(CH3)2(CH2)3NH2, etc.

[0116] Examples of polyamideimide resins include resins having imide bonds and amide bonds in the repeating units.

[0117] More specifically, examples of polyamideimide resins include polymers of trivalent carboxylic acid compounds (also referred to as tricarboxylic acids) having acid anhydride groups and diisocyanate compounds or diamine compounds.

[0118] As the tricarboxylic acid, trimellitic anhydride and its derivatives are preferred. In addition to the tricarboxylic acid, a tetracarboxylic dianhydride, an aliphatic dicarboxylic acid, an aromatic dicarboxylic acid, etc. may also be used in combination.

[0119] 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, naphthalene-2,6-diisocyanate, etc.

[0120] Examples of the diamine compound include: a compound having the same structure as the above-mentioned isocyanate and having an amino group instead of an isocyanate group.

[0121] In the resin base material layer, other components may be included in addition to the resin. Examples of other components include, for example: a conductive material, a filler for improving mechanical strength, an antioxidant for preventing thermal deterioration, a surfactant, a heat-resistant anti-aging agent, etc.

[0122] Here, an example in which the first rotating body is a pressure roller and the second rotating body is a pressure belt is given, and a mode in which the first rotating body is a pressure roller and the second rotating body is a heating belt is also included.

[0123] When the first rotating body is a pressure roller, the structure of the pressure roller is preferably the same as the structure of the above-mentioned pressure roller 52.

[0124] When the second rotating body is a heating belt, the structure of the heating belt is preferably the same as the structure of the above-mentioned pressure belt 62.

[0125] In particular, when the second rotating body is a heating belt, it may be a single layer body of the resin base material layer constituting the inner peripheral surface of the heating belt, or a laminate having a resin base material layer constituting the inner peripheral surface of the heating belt, an elastic layer provided on the resin base material layer, and a release layer provided on the elastic layer; or a laminate having a resin base material layer constituting the inner peripheral surface of the heating belt and a release layer provided on the resin base material layer; or a laminate in which a metal layer is provided on the inner peripheral surface of the resin base material layer constituting the heating belt, an elastic layer is provided thereon, and a release layer is provided on the elastic layer.

[0126] The elastic layer will be described.

[0127] The elastic layer is composed of a heat-resistant elastic material.

[0128] As heat-resistant elastic materials, for example, silicone rubber, fluororubber, etc. can be cited.

[0129] As silicone rubber, for example, RTV (Room Temperature Vulcanizing) silicone rubber, HTV (High Temperature Vulcanizing) silicone rubber, liquid silicone rubber, etc. can be cited. Specifically, polydimethylsilicone rubber, methyl vinyl silicone rubber, methyl phenyl silicone rubber, fluorosilicone rubber, etc. can be cited.

[0130] As fluororubber, vinylidene fluoride-based rubber, tetrafluoroethylene / propylene-based rubber, tetrafluoroethylene / perfluoromethyl vinyl ether rubber, phosphazene-based rubber, fluoropolyether, etc. can be cited.

[0131] The elastic layer may also contain other components. As other components, for example, filler materials, conductive materials, softeners (such as paraffin-based), processing aids (such as stearic acid), anti-aging agents (such as amine-based), vulcanizing agents (such as sulfur, metal oxides, peroxides, etc.), functional filler materials (such as alumina), etc. can be cited.

[0132] The release layer will be described.

[0133] The release layer contains, for example, a heat-resistant release material.

[0134] As heat-resistant release materials, fluororubber, fluororesin, silicone resin, polyimide resin, etc. can be cited.

[0135] Among them, as the heat-resistant release material, fluororesin is preferably used. As fluororesin, specifically, for example, polytetrafluoroethylene (PTFE); tetrafluoroethylene-perfluoromethyl vinyl ether copolymer (MFA), tetrafluoroethylene-perfluoroethyl vinyl ether copolymer (EFA), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) such as tetrafluoroethylene-perfluoropropyl vinyl ether copolymer, etc. can also be cited. Tetrafluoroethylene-hexafluoropropylene copolymer (FEP), ethylene-tetrafluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), polyvinyl fluoride (PVF), etc. can also be cited.

[0136] Among them, especially considering heat resistance, mechanical properties, etc., it is suitable to use polytetrafluoroethylene (PTFE), and tetrafluoroethylene-perfluoromethyl vinyl ether copolymer (MFA), tetrafluoroethylene-perfluoroethyl vinyl ether copolymer (EFA) and other tetrafluoroethylene-perfluoroalkyl vinyl ether copolymers (PFA).

[0137] The thickness of the release layer is preferably set to 5 μm to 100 μm, and more preferably set to 10 μm to 30 μm.

[0138] - Pressing member 68 (an example of a pressing member)-

[0139] As shown in Figure 2 , the pressing member 68 is disposed on the inner peripheral surface 90 of the pressing belt 62 and on the side opposite to the pressing roller 52 with the planar heating element 64 interposed therebetween. The pressing member 68 is formed of a resin material such as LCP (liquid crystal polymer) having high heat resistance and extends in the device depth direction.

[0140] Moreover, the cross-section orthogonal to the length direction of the pressing member 68 is U-shaped with an opening on the side of the planar heating element 64. When viewed from the device depth direction, the pressing member 68 is in contact with the planar heating element 64 at both ends of the pressing member 68 and holds the planar heating element 64.

[0141] - Planar heating element 64 (an example of a sliding member)-

[0142] The sliding member is interposed between the inner peripheral surface of the second rotating body and the pressing member.

[0143] The sliding member may be a resin sheet made of a heat-resistant resin or may be in a form having a planar heating element such as a metal plate, as long as it is a member having irregularities on the sliding surface and the surface roughness Ra1 and the load length ratio Rmr satisfy the values within the above ranges. In addition, when the sliding member is a resin sheet, well-known other additives may be added to the sliding member. The sliding member may be a single type or two or more types may be used in combination. Moreover, when two or more sliding members include the planar heating element 64, the sliding member serving as the planar heating element 64 is disposed on the sliding surface side.

[0144] Examples of the heat-resistant resin include: fluororesin, polyimide resin, polyamide resin, polyamideimide resin, polyetherimide resin, polyethersulfone resin, polyetherketone resin, bismaleimide triazine resin, aramid resin, polyphenylene resin, polyphenylene sulfide resin, etc. However, from the viewpoints of heat resistance and slidability, fluororesin is preferred.

[0145] Among fluororesins, fluororesin subjected to electron beam crosslinking is also preferably cited. Specifically, for example, polytetrafluoroethylene (PTFE) subjected to electron beam crosslinking is preferably cited. In addition, fluororesin subjected to electron beam crosslinking (for example, electron beam crosslinked PTFE) may be used in combination with non-crosslinked fluororesin (for example, non-crosslinked PTFE).

[0146] In addition, the heat-resistant resin means a resin that does not melt or decompose even when reaching the temperature rise temperature of the device (for example, the fixing temperature).

[0147] The sliding part may also be a porous part (a part having a plurality of pores). Thus, the lubricant retention capacity is improved. Examples of the porous sliding part include a part made porous by foaming a heat-resistant resin, a part made porous by extending a heat-resistant resin in a uniaxial or biaxial direction, or a sintered part.

[0148] When a porous sliding member is used, it is preferable to interpose a lubricant penetration preventing member (sheet member) for preventing the lubricant S from penetrating toward the pressing member 68 side between the sliding member and the pressing member 68 .

[0149] From the viewpoint of appropriately satisfying the above ranges for the surface roughness Ra1 and the load length ratio Rmr and further improving the fixability to the recording medium, the sliding component is preferably a planar heating element such as a metal plate, and more preferably a planar heating element having a glass layer on the sliding surface.

[0150] The planar heating element is formed of a plate-like body that is long along the length direction of the heating part such as the bite part, and has: an electrically insulating substrate; an insulating layer formed of a heat-resistant resin of the polyimide series; a pair of electrodes for power supply; and a resistor body, such as stainless steel, that generates heat by supplying power from the electrodes. In addition, the electrode and the resistor body are connected through a power supply part, and the electrode, the power supply part and the resistive heating part are buried in the insulating layer. Moreover, the electrode of the planar heating element is grounded through the resistor body.

[0151] In addition, the glass layer refers to the following concepts: silica glass; water glass (including a sodium salt of metasilicic acid, sodium silicate and other aqueous solutions); oxide glass (for example, borate glass with B2O3 as the main component, glass with P2O5, GeO2, TeO2, V2O5 and the like as the main component); non-oxide glass (for example, including glass with chalcogenides such as As2S3, GeS2, As2Se3 as the main component); halide glass such as ZrF4, BaF2, AlF3, etc. In addition, silica glass refers to a layer of silicon dioxide that does not have a clear crystalline state (that is, in an amorphous state) in the diffraction spectrum obtained by the powder X-ray diffraction method. Among the above, the glass layer is preferably silica glass.

[0152] -Lubricant S-

[0153] The lubricant S is interposed between the inner peripheral surface of the pressure belt 62 and the sliding member.

[0154] As the lubricant S, for example, the following can be cited: grease, silicone oil (e.g., dimethyl silicone oil, methylphenyl silicone oil, amino-modified silicone oil, carboxyl-modified silicone oil, silanol-modified silicone oil, sulfonic acid-modified silicone oil, etc.), fluorine oil (e.g., fluorinated silicone oil, perfluoropolyether oil, etc.). Among them, from the viewpoint of making the viscosity of the lubricant within the range described below, the lubricant preferably contains silicone oil, and more preferably contains long-chain alkyl-modified silicone oil (e.g., having 3 or more carbon atoms).

[0155] The lubricant may also contain other additives (such as antioxidants, etc.).

[0156] The viscosity of the lubricant is preferably 20 mm 2 / s or more and 1000 mm 2 / s or less, more preferably 50 mm 2 / s or more and 600 mm 2 / s or less, further preferably 50 mm 2 / s or more and 300 mm 2 / s or less.

[0157] If the viscosity of the lubricant is set within the above range, appropriate fluidity and retention are imparted, and the lubricant is easily interposed between the inner peripheral surface of the second rotating body and the pressing member. In addition, when damage or the like occurs on the inner peripheral surface of the second rotating body, it is also easy to fill the lubricant into the portion where such damage or the like has occurred.

[0158] The method of making the viscosity of the lubricant within the above range is not particularly limited. For example, the following method can be cited: using a lubricant in which the side chain is a low-molecular-weight long-chain alkyl-modified silicone oil with relatively low intermolecular interaction and the molecular weight of the main chain is adjusted.

[0159] The viscosity of the lubricant is the viscosity at room temperature (23 °C) and is measured by a rotational viscometer RHEOMAT 115 (manufactured by Contraves).

[0160] In addition to oil, the lubricant S may also contain other components. As other components, the following can be cited: grease (such as silicone grease), heat conductive agent, antioxidant, surfactant, silicon particles, organic metal salt, hindered amine, etc.

[0161] (Image forming operation of the image forming apparatus)

[0162] Next, the image forming operation of the image forming apparatus of the present embodiment will be described. In addition, the image forming operation will be described by taking the operation of forming a yellow image in the first processing cartridge 10Y as an example.

[0163] First, before the image forming operation, the surface of the photoreceptor 1Y is charged to a potential of about -600 V, for example, by the charging roller 2Y.

[0164] The photoreceptor 1Y is formed, for example, by laminating a photosensitive layer on a conductive substrate. This photosensitive layer has, for example, the property of being generally highly resistive but having its specific resistance changed in the portion irradiated with the laser light 3Y when irradiated with the laser light. Then, according to the yellow image data sent from a control unit (not shown), the laser light 3Y is output to the surface of the charged photoreceptor 1Y via the exposure device 3. The laser light 3Y irradiates the photosensitive layer on the surface of the photoreceptor 1Y, whereby an electrostatic latent image of the yellow printing pattern is formed on the surface of the photoreceptor 1Y.

[0165] In this way, the electrostatic latent image formed on the photoreceptor 1Y rotates to the developing position as the photoreceptor 1Y travels. Then, at this developing position, the electrostatic latent image on the photoreceptor 1Y becomes a visible image (toner image) through the developing device 4Y.

[0166] In the developing device 4Y, for example, a developer containing yellow toner and a carrier is housed. The yellow toner is agitated and triboelectrically charged inside the developing device 4Y and has a charge of the same polarity (negative polarity) as the charge carried on the photoreceptor 1Y. The surface of the photoreceptor 1Y passes through the developing device 4Y, whereby the yellow toner electrostatically adheres only to the discharged latent image portion on the surface of the photoreceptor 1Y, and the latent image is developed with the yellow toner. The photoreceptor 1Y having the yellow toner image formed thereon continues to travel, and the toner image developed on the photoreceptor 1Y is transferred to the primary transfer position.

[0167] When the yellow toner image on the photoreceptor 1Y is transferred to the primary transfer position, a primary transfer bias is applied to the primary transfer roller 5Y, and an electrostatic force from the photoreceptor 1Y toward the primary transfer roller 5Y acts on the toner image, and the toner image on the photoreceptor 1Y is transferred to the intermediate transfer belt 20. The transfer bias applied at this time is of the opposite polarity (+) to the polarity (-) of the toner, and is, for example, controlled to be about +10 μA by a constant current by a control unit (not shown) in the first process cartridge 10Y.

[0168] In addition, the primary transfer biases applied to the primary transfer rollers 5M, 5C, 5K after the second process cartridge 10M are also controlled in the same manner.

[0169] In this way, the intermediate transfer belt 20 having the yellow toner image transferred thereon in the first process cartridge 10Y is sequentially conveyed through the second to fourth process cartridges 10M, 10C, 10K, and the toner images of each color are similarly overlapped and multi-transferred.

[0170] Through the first to fourth processing cartridges, the intermediate transfer belt 20 that has transferred toner images of all colors multiple times reaches the secondary transfer section, which is composed of the intermediate transfer belt 20, a support roller 24 that contacts the inner peripheral surface of the intermediate transfer belt 20, and a secondary transfer roller (an example of a secondary transfer device) 26 disposed on the image holding surface side of the intermediate transfer belt 20. On the other hand, the recording medium P is supplied 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 is a (-) polarity that is the same polarity as the polarity (-) of the toner. An electrostatic force acting from the intermediate transfer belt 20 toward the recording medium P acts on the toner image, and the toner image on the intermediate transfer belt 20 is transferred onto the recording medium P. In addition, the secondary transfer bias at this time is determined based on the resistance detected by a resistance detection unit (not shown) that detects the resistance of the secondary transfer section, and is controlled with a constant voltage.

[0171] In addition, the intermediate transfer belt 20, the primary transfer roller 5Y, and the secondary transfer roller 26 are examples of a transfer device.

[0172] After that, the recording medium P is conveyed to the fixing device 60 and is inserted into the contact area formed by the pressure roller 52 and the pressure belt 62 that are rotationally driven in the arrow direction and are in pressure contact. At this time, the recording medium P is inserted in such a manner that the surface of the recording medium P on which the unfixed toner image is formed faces the surface of the pressure roller 52. When the recording medium P passes through this contact area, by applying heat and pressure to the recording medium P, the unfixed toner image is fixed on the recording medium P. After the fixed recording medium passes through the contact area, it is peeled off from the pressure roller 52 and discharged from the fixing device 60.

[0173] In this way, the fixing process is completed and permanently fixed on the recording medium P. The recording medium P on which the fixing of the color image has been completed is conveyed toward the discharge section, and a series of color image forming operations are completed.

[0174] [Embodiment]

[0175] The following describes embodiments, but the present invention is not limited to these embodiments. In addition, in the following description, unless otherwise specified, "parts" and "%" are based on mass.

[0176] <Manufacture of the Pressure Belt>

[0177] (Manufacture of the Pressure Belt (1))

[0178] By setting the shot peening time per unit area to 1 min / mm 2On the surface of an aluminum cylindrical core body with an uneven shape formed on the surface by shot peening (with a bead diameter of 100 μm), a silicone-based release agent was applied, and after drying at 300 °C for 1 hour, an N-methylpyrrolidone solution containing a precursor of polyimide resin was dip-coated on the surface and dried at 100 °C for 1 hour. Thus, a resin base material layer constituting the inner peripheral surface of the pressure belt was formed.

[0179] Next, a fluororesin dispersion (specifically, a PTFE dispersion) was applied to the outer peripheral surface of the resin base material layer. Then, after drying at 60 °C for 10 minutes in a baking furnace, it was gradually heated to 380 °C, baked for 20 minutes, and then cooled to room temperature to form a release layer.

[0180] After that, the resin base material layer with the release layer formed was removed from the core body and cut into the target size by a cutting machine to obtain the pressure belt (1).

[0181] (Manufacture of pressure belt (2))

[0182] Except that the shot peening time per unit area was set to 5 min / mm 2 To adjust the surface roughness of the aluminum cylindrical core body with an uneven shape formed on the surface by shot peening, the pressure belt (2) was obtained in the same manner as the manufacture of the pressure belt (1).

[0183] (Manufacture of pressure belt (3))

[0184] Except that the shot peening time per unit area was set to 0 min / mm 2 To adjust the surface roughness of the aluminum cylindrical core body with an uneven shape formed on the surface by shot peening, the pressure belt (3) was obtained in the same manner as the manufacture of the pressure belt (1).

[0185] (Manufacture of pressure belt (4))

[0186] Except that 30 parts of SiC particles (FUJIMI INCORPORATED) were added to the polyimide precursor solution, the pressure belt (4) was obtained in the same manner as the manufacture of the pressure belt (1).

[0187] (Manufacture of pressure belt (5))

[0188] Except that 15 parts of SiC particles (FUJIMI INCORPORATED) were added to the polyimide precursor solution, the pressure belt (5) was obtained in the same manner as the manufacture of the pressure belt (1).

[0189] <Manufacture of sliding member>

[0190] (Manufacture of sliding member (1))

[0191] Print a resistive heating part made of stainless steel on an alumina substrate and bake it at 850 °C. After that, after measuring the resistance value, print a pair of electrodes and further bake them at 850 °C. Then, coat the surface with silica glass to cover the electrodes and the resistive heating part. After baking at 850 °C, bake it again at 870 °C. After that, grind the surface with sandpaper having a particle size of 0.1 μm until the load length ratio Rmr reaches the value shown in Table 1, and obtain the sliding member (1) as a planar heating element.

[0192] (Manufacture of sliding member (2))

[0193] Obtain the sliding member (2) as a planar heating element in the same manner as the manufacture of the sliding member (1), except that the re-baking temperature after coating the surface with silica glass is set to 950 °C.

[0194] (Manufacture of sliding member (3))

[0195] Obtain the sliding member (3) as a planar heating element in the same manner as the manufacture of the sliding member (1), except that the re-baking temperature after coating the surface with silica glass is set to 600 °C.

[0196] (Manufacture of sliding member (4))

[0197] Obtain the sliding member (4) as a planar heating element in the same manner as the manufacture of the sliding member (1), except that the processing time using sandpaper is set to twice.

[0198] (Manufacture of sliding member (5))

[0199] Obtain the sliding member (5) as a planar heating element in the same manner as the manufacture of the sliding member (1), except that the processing time using sandpaper is set to 0.75 times.

[0200] (Manufacture of sliding member (6))

[0201] Obtain the sliding member (6) as a planar heating element in the same manner as the manufacture of the sliding member (1), except that the re-baking temperature after coating the surface with silica glass is set to 870 °C, and after cooling, bake it again at 870 °C.

[0202] (Manufacture of sliding member (7))

[0203] Obtain the sliding member (7) as a planar heating element in the same manner as the manufacture of the sliding member (1), except that the silica glass is changed to tempered glass (product name Panda King, manufacturer Xuhong).

[0204] (Manufacture of the sliding member (8))

[0205] Except for electroless nickel plating on the glass surface, the sliding member (8) as a planar heating element is obtained by the same method as the manufacture of the sliding member (1).

[0206] (Manufacture of the sliding member (9))

[0207] The polyether ether ketone resin (PEEK) (Victrex450G, manufactured by Victrex Corporation) is heated and melted at 380 °C using a twin-screw compression melting mixer (twin-screw melting and kneading extruder L / D60, manufactured by Parker Corporation). Silicone resin particles are supplied from the side of the mixer using a side feeder, and melted and kneaded. The kneaded melt is put into a water tank and cooled and solidified, and cut into a target size to obtain mixed resin pellets containing silicone resin particles.

[0208] The obtained mixed resin pellets are put into a single-screw extrusion device, and the molten mixed resin is extruded into a sheet through a T-die (molten discharge gap 200 μm) heated to 380 °C, and wound around a cooling roll at 190 °C and cooled. A roll with a 100-mesh SUS wire mesh wound around its surface is used to give a shape to the cooled sheet at 400 °C and a pressure of 10 Mpa to obtain a sheet with unevenness. The sheet with unevenness is cut into a specified size. This is used as the sliding member (9).

[0209] (Manufacture of the sliding member (10))

[0210] Except that the re-baking temperature after coating the surface with silica glass is set to 600 °C and the treatment time using sandpaper is set to 1.5 times, the sliding member (10) as a planar heating element is obtained by the same method as the manufacture of the sliding member (1).

[0211] (Manufacture of the sliding member (11))

[0212] Except that the sandpaper treatment time is set to 0.9 times, the sliding member (11) as a planar heating element is obtained by the same method as the manufacture of the sliding member (1).

[0213] The ten-point average roughness of the sliding surface on each sliding member is measured based on the JIS B-0601 standard. The respective results are shown in Table 1. In addition, the following properties obtained by the above measurement method are summarized and shown in Table 1.

[0214] · Surface roughness Ra1 of the sliding surface of the sliding member

[0215] · Load length ratio Rmr of the sliding surface of the sliding member

[0216] ·Surface roughness Ra2 of the inner peripheral surface of the second rotating body

[0217] ·Hardness A of the sliding surface of the sliding member

[0218] ·Hardness B of the inner peripheral surface of the second rotating body

[0219] ·Difference (Surface roughness Ra2 of the inner peripheral surface of the second rotating body - Surface roughness Ra1 of the sliding surface of the sliding member)

[0220] ·Difference (Hardness A of the sliding surface of the sliding member - Hardness B of the inner peripheral surface of the second rotating body)

[0221] ·Viscosity of the lubricant

[0222] <Lubricant>

[0223] ·Lubricant (1): Long-chain alkyl-modified silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., product name KF-4003)

[0224] ·Lubricant (2): Fluoroalkyl-modified silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., product name FL-100-1000CS)

[0225] ·Lubricant (3): Long-chain alkyl-modified silicone oil (manufactured by Shin-Etsu Chemical Co., Ltd., product name KF-4917)

[0226] <Examples 1 to 17, Comparative Examples 1 to 6>

[0227] Install the pressure belt, sliding member, and lubricant on the fixing device of the image forming apparatus "modified machine of APEOS PORT Print C5570" manufactured by FUJIFILM Business Innovation Co., Ltd. according to the combinations shown in Table 1.

[0228] Use this device as the image forming apparatus for each example and conduct the following evaluation.

[0229] <Evaluation: Presence or absence of damage on the inner peripheral surface of the pressure belt>

[0230] Continuously output a solid image (blue solid 100% density) onto A4 paper (1000 kPV). Then, remove the pressure belt from the image forming apparatus and visually evaluate the damage to the 100 mm × 100 mm width area on the inner peripheral surface of the pressure belt according to the following criteria.

[0231] A: No damage

[0232] B: One or more damages less than 10 can be confirmed

[0233] C: It is possible to confirm more than 10 and less than 50 damages

[0234] D: It is possible to confirm 50 or more damages

[0235] <Evaluation: Torque Rise of the Pressure Belt>

[0236] Regarding the torque rise of the pressure belt, the measurement is carried out as follows.

[0237] Engage the measuring gear of the direct torque meter (manufactured in Fuji Xerox Co., Ltd.) with the gear part of the fixing roller, and measure the value A0 of the torque during the initial drive of the fixing roller and the value A of the torque required when driving at 100 kPV 100 (Unit: Nm). Evaluate the drive torque rise (A 100 - A0) of the fixing roller as the torque rise value of the pressure belt.

[0238] When the drive torque rises excessively, it places a burden on the drive gear of the fixing roller as the drive source, and there are practical problems. Examples of particularly bad phenomena include: wrinkles are generated on the paper for obtaining an image; or abnormal noises of the gear are generated.

[0239] In addition, in the comparative example, the number of sheets of paper output (kPV = 1000 sheets of paper output) when the drive torque reaches 0.9 N·m is shown.

[0240] [Table 1]

[0241]

[0242] From the above results, it can be seen that the fixing device of the present embodiment suppresses the wear and damage of the inner peripheral surface of the pressure belt (second rotating body) and, moreover, suppresses the rise of the torque of the pressure belt as compared with the fixing device of the comparative example.

[0243] (Supplementary Note) (((1)))

[0245] A fixing device

[0246] It includes:

[0247] A first rotating body

[0248] A second rotating body, which is disposed in contact with the first rotating body

[0249] A pressing member, which is disposed on the inner peripheral surface of the second rotating body and presses the second rotating body from the inner peripheral surface of the second rotating body against the first rotating body

[0250] A sliding member, which is interposed between the inner peripheral surface of the second rotating body and the pressing member; and

[0251] A lubricant is provided between the inner circumferential surface of the second rotating body and the sliding member.

[0252] The sliding surface of the sliding member has irregularities, the surface roughness Ra1 is 0.20 μm or more, and the load length ratio Rmr is 35% or more. ((2))

[0254] The fixing device according to ((1)), wherein

[0255] The surface roughness Ra1 is 0.20 μm or more and 5.00 μm or less. ((3))

[0257] The fixing device according to ((1)) or ((2)), wherein

[0258] The load length ratio Rmr is 36% or more and 75% or less. ((4))

[0260] The fixing device according to any one of ((1)) to ((3)), wherein

[0261] The sliding member has a planar heating element. ((5))

[0263] The fixing device according to ((4)), wherein

[0264] The sliding member has a glass layer on the sliding surface. ((6))

[0266] The fixing device according to any one of ((1)) to ((5)), wherein

[0267] The surface roughness Ra1 of the sliding surface of the sliding member

[0268] is a value smaller than the surface roughness Ra2 of the inner circumferential surface of the second rotating body. ((7))

[0270] The fixing device according to ((6)), wherein

[0271] The surface roughness Ra1 of the sliding surface of the sliding member

[0272] The difference (Ra2 - Ra1) from the surface roughness Ra2 of the inner circumferential surface of the second rotating body is 0.05 μm or more and 2.00 μm or less. (((8)))

[0274] The fixing device according to any one of the above ((1)) to ((7)), wherein,

[0275] The hardness A of the sliding surface of the sliding member

[0276] is a value higher than the hardness B of the inner peripheral surface of the second rotating body. (((9)))

[0278] The fixing device according to the above ((8)), wherein,

[0279] The hardness A of the sliding surface of the sliding member

[0280] The difference (A - B) between the hardness A of the sliding surface of the sliding member and the hardness B of the inner peripheral surface of the second rotating body is 10 or more and 600 or less. (((10)))

[0282] The fixing device according to any one of the above ((1)) to ((9)), wherein,

[0283] The viscosity of the lubricant is 20 mm 2 / s or more and 1000 mm 2 / s or less. (((11)))

[0285] An image forming apparatus, comprising:

[0286] An image holding member;

[0287] A latent image forming device that forms a latent image on the surface of the image holding member;

[0288] A developing device that develops the latent image into a toner image using a developer;

[0289] A transfer device that transfers the developed toner image onto a recording medium; and

[0290] The fixing device according to any one of the above ((1)) to ((10)), which fixes the toner image on the recording medium.

[0291] According to ((1)), a fixing device can be provided that can reduce damage to the inner peripheral surface of the fixing member compared with the case where the surface roughness Ra1 of the sliding surface of the sliding member is less than 0.20 μm or the load length ratio Rmr of the sliding surface of the sliding member is less than 35% in a specific fixing device.

[0292] According to (((2))), a fixing device can be provided which can reduce the damage to the inner peripheral surface of the fixing member as compared with a case where in a specific fixing device, the surface roughness Ra1 is less than 0.20 μm or exceeds 5.00 μm.

[0293] According to (((3))), a fixing device can be provided which can reduce the damage to the inner peripheral surface of the fixing member as compared with a case where in a specific fixing device, the load length ratio Rmr is less than 36% or exceeds 75%.

[0294] According to (((4))), a fixing device can be provided which can reduce the damage to the inner peripheral surface of the fixing member as compared with a case where in a specific fixing device, the sliding member is a pressing member without a heater.

[0295] According to (((5))), a fixing device can be provided which can reduce the damage to the inner peripheral surface of the fixing member as compared with a case where in a specific fixing device, the sliding member does not have a glass layer on the sliding surface.

[0296] According to (((6))), a fixing device can be provided which can reduce the damage to the inner peripheral surface of the fixing member as compared with a case where in a specific fixing device, the surface roughness Ra1 of the sliding surface of the sliding member is a value larger than the surface roughness Ra2 of the inner peripheral surface of the second rotating body.

[0297] According to (((7))), a fixing device can be provided which can reduce the damage to the inner peripheral surface of the fixing member as compared with a case where in a specific fixing device, the difference (Ra2 - Ra1) between the surface roughness Ra1 of the sliding surface of the sliding member and the surface roughness Ra2 of the inner peripheral surface of the second rotating body is less than 0.05 μm or exceeds 2.00 μm.

[0298] According to (((8))), a fixing device can be provided which can reduce the damage to the inner peripheral surface of the fixing member as compared with a case where in a specific fixing device, the hardness A of the sliding surface of the sliding member is a value lower than the hardness B of the inner peripheral surface of the second rotating body.

[0299] According to (((9))), a fixing device can be provided which can reduce the damage to the inner peripheral surface of the fixing member as compared with a case where in a specific fixing device, the difference (A - B) between the hardness A of the sliding surface of the sliding member and the hardness B of the inner peripheral surface of the second rotating body is less than 10 or exceeds 600.

[0300] According to (((10))), a fixing device can be provided which can reduce the damage to the inner peripheral surface of the fixing member as compared with a case where in a specific fixing device, the viscosity of the lubricant is less than 20 mm 2 / s or exceeds 1000 mm 2 / s.

[0301] According to (((11))), an image forming apparatus can be provided that can reduce damage to the inner peripheral surface of a fixing member as compared with an image forming apparatus having a fixing device in which the surface roughness Ra1 of the sliding surface of the sliding member is less than 0.20 μm or the load length ratio Rmr of the sliding surface of the sliding member is less than 35%.

Claims

1. A fixing device, characterized in that: have: a first rotating body; a second rotating body, the second rotating body being arranged in contact with the first rotating body; a pressing member, the pressing member being disposed 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, the sliding member being interposed between the inner peripheral surface of the second rotating body and the pressing member; as well as a lubricant interposed between the inner peripheral surface of the second rotating body and the sliding member, The sliding surface of the sliding member has projections and depressions, a surface roughness Ra1 of 0.20 μm or more, and a load length ratio Rmr of 35% or more.

2. The fixing device according to claim 1, wherein: The surface roughness Ra1 is greater than or equal to 0.20 μm and less than or equal to 5.00 μm.

3. The fixing device according to claim 1 or 2, wherein: The load length ratio Rmr is greater than or equal to 36% and less than or equal to 75%.

4. The fixing device according to any one of claims 1 to 3, wherein: The sliding member has a planar heating element.

5. The fixing device according to claim 4, wherein: The sliding component has a glass layer on the sliding surface.

6. The fixing device according to any one of claims 1 to 5, wherein: The surface roughness Ra1 of the sliding surface of the sliding member is smaller than the surface roughness Ra2 of the inner peripheral surface of the second rotating body.

7. The fixing device according to claim 6, wherein: A difference (Ra2-Ra1) between a surface roughness Ra1 of the sliding surface of the sliding member and a surface roughness Ra2 of an inner peripheral surface of the second rotating body is 0.05 μm or more and 2.00 μm or less.

8. The fixing device according to any one of claims 1 to 7, wherein: A hardness A of the sliding surface of the sliding member is a value higher than a hardness B of an inner peripheral surface of the second rotating body.

9. The fixing device according to claim 8, wherein: A difference (AB) between a hardness A of the sliding surface of the sliding member and a hardness B of an inner peripheral surface of the second rotating body is 10 or more and 600 or less.

10. The fixing device according to any one of claims 1 to 9, wherein: The viscosity of the lubricant is 20 mm 2 / s or more and 1000mm 2 / s or less.

11. An image forming device, characterized in that: have: Like holding body; A latent image forming device, wherein the latent image forming device forms a latent image on the surface of the image holding body; a developing device that develops the latent image into a toner image using a developer; a transfer device for transferring the developed toner image onto a recording medium; as well as The fixing device according to any one of claims 1 to 10, The fixing device fixes the toner image on the recording medium.

Images