JP2018036595A - Fixing roll, fixing device, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce peeling of a surface layer from an elastic layer when a fixing roll is used, compared with a case where an elastic layer including periodic irregularities on its surface is not formed on the axial direction surface of a fixing roll.SOLUTION: A fixing roll 52 comprises: a cylindrical substrate 60; an elastic layer 62 that is formed on the periphery of the substrate 60 and includes periodic irregularities 63 on its surface on the axial direction cross section; and a surface layer 66 that is provided on the surface of the elastic layer 62 with an adhesion layer 64 therebetween.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a fixing roll, a fixing device, and an image forming apparatus.

  In the following Patent Document 1, as an application method by flow coating, the tip of the dispenser is brought into contact with the outer peripheral surface of the core body, and the movement speed V (mm / second) of the dispenser supply unit in the direction of the axis of rotation of the core body, A method is disclosed in which the ratio of the rotational speed R (rotation / second) of the core body is within a range represented by V / R <1.5 (mm / rotation).

  In the following Patent Document 2, there is a method of applying a solution by supplying a solution to a coating nozzle with a rotary volume moving pump while rotating the core for the purpose of making the film thickness uniform by a flow coat coating method. It is disclosed.

JP 09-85756 A JP 2004-160310 A

  In a state where the opposing member is pressed against the fixing roll in the image forming apparatus, the fixing roll may be repeatedly subjected to thermal deterioration stress and shear stress, and peeling between layers of the fixing roll may occur.

  The present invention relates to a fixing roll, a fixing device, and an image forming apparatus in which peeling between a surface layer and an elastic layer during use of the fixing roll is suppressed as compared with a configuration in which an elastic layer has a smooth surface.

  The fixing roll according to the first aspect of the present invention includes a cylindrical base material, an elastic layer that is formed around the base material and has periodic irregularities on the surface in an axial cross section, and the elastic layer And a surface layer provided on the surface via an adhesive layer.

  According to a second aspect of the present invention, in the fixing roll according to the first aspect, the waviness Wc-t which is a periodic unevenness on the surface of the elastic layer is 5 μm or more and 30 μm or less.

  According to a third aspect of the present invention, in the fixing roll according to the first or second aspect, the width of the periodic unevenness on the surface of the elastic layer is 1 mm or more and 30 mm or less.

  According to a fourth aspect of the present invention, a fixing device includes the fixing roll according to any one of the first to third aspects, and a facing member that is pressed against the fixing roll.

  According to a fifth aspect of the present invention, an image forming apparatus includes: an image forming unit that forms a toner image on a medium; and the fixing device according to the fourth aspect that fixes the toner image formed on the medium.

  According to the first aspect of the present invention, the peeling between the surface layer and the elastic layer during use of the fixing roll is suppressed as compared with the configuration in which the elastic layer has a smooth surface.

  According to the second aspect of the present invention, the undulation Wc-t, which is the unevenness of the surface of the elastic layer, is less than 5 μm, and the peeling between the surface layer and the elastic layer during use of the fixing roll is suppressed. In addition, the generation of vertical streaks is suppressed as compared to the case where the undulation Wc-t, which is the unevenness of the surface of the elastic layer, is larger than 30 μm.

  According to the invention described in claim 3, the surface layer and the elastic layer are prevented from being peeled off when the fixing roll is used, as compared with the case where the width of the unevenness on the surface of the elastic layer is smaller than 1 mm. The occurrence of vertical streaks is suppressed as compared with the case where the width (period) of the unevenness on the surface is larger than 30 mm.

  According to the fourth aspect of the present invention, the life of the fixing roll is extended when the opposing member is pressed against the fixing roll, as compared with the configuration in which the fixing roll having the smooth surface of the elastic layer is provided. Is realized.

  According to the fifth aspect of the present invention, the life of the fixing roll is extended when the opposing member is brought into pressure contact with the fixing roll, as compared with the configuration in which the fixing roll having a smooth surface of the elastic layer is provided. Is realized.

1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an embodiment of the present invention. FIG. 2 is a cross-sectional view illustrating a fixing roll according to an embodiment used in the image forming apparatus illustrated in FIG. 1. FIG. 3 is an enlarged cross-sectional view showing an enlarged state of the surface side of the fixing roll shown in FIG. 2. FIG. 3 is a cross-sectional view illustrating a part of a fixing device including the fixing roll illustrated in FIG. 2. FIG. 6 is a diagram showing the results of evaluating the image quality of the fixing rolls of Examples 1 to 5 and the fixing roll of Comparative Example 1.

  Hereinafter, an image forming apparatus according to an embodiment of the present invention will be described with reference to the drawings. In addition, in this specification, when there exists a numerical range represented using "to", a numerical range means the range which includes the numerical value described before and behind "to" as a lower limit and an upper limit.

<Overall configuration of image forming apparatus>
FIG. 1 is a schematic configuration diagram illustrating an example of a configuration of an image forming apparatus including a fixing roll according to an embodiment. As shown in FIG. 1, the image forming apparatus 40 is a first electrophotographic system that outputs images of each color of yellow (Y), magenta (M), cyan (C), and black (K) based on image data. To fourth image forming units 10Y, 10M, 10C, and 10K. These image forming units (hereinafter sometimes simply referred to as “units”) 10Y, 10M, 10C, and 10K are arranged in parallel at a predetermined distance from each other in the horizontal direction. Here, the image forming unit 10 is an example of an image forming unit.

  Above each of the units 10Y, 10M, 10C, and 10K, an intermediate transfer belt 20 is provided so as to straddle each unit. The intermediate transfer belt 20 is supported from the inner surface of the intermediate transfer belt 20 by a drive roll 22 and a support roll 24 that are spaced apart from each other in the left-right direction (direction intersecting the up-down direction) in the drawing. The vehicle travels in a direction from the unit 10Y toward the fourth unit 10K. The support roll 24 is applied with a force in a direction away from the drive roll 22 by a spring or the like (not shown), and tension is applied to the intermediate transfer belt 20 supported by both. A cleaning device 30 that cleans the surface of the intermediate transfer belt 20 is provided outside the intermediate transfer belt 20 at a position facing the drive roll 22. The cleaning device 30 includes a cleaning blade 42 and a cleaning roll 44 that come into contact with the intermediate transfer belt 20. Here, the intermediate transfer belt 20 is an example of an image forming unit.

  Each of the developing devices 4Y, 4M, 4C, and 4K of the units 10Y, 10M, 10C, and 10K has four colors of yellow, magenta, cyan, and black contained in the toner cartridges 8Y, 8M, 8C, and 8K. Toner including toner is supplied.

  Since the first to fourth units 10Y, 10M, 10C, and 10K have the same configuration, the first unit that forms the yellow image disposed on the upstream side in the running direction of the intermediate transfer belt 20 is used here. The unit 10Y will be described as a representative. It should be noted that reference numerals with magenta (M), cyan (C), and black (K) are attached to the same parts as those of the first unit 10Y instead of yellow (Y). Description of the units 10M, 10C, and 10K will be omitted.

  The first unit 10Y has a photoreceptor 1Y. Around the photoconductor 1Y, a charging roll 2Y that charges the surface of the photoconductor 1Y to a predetermined potential, and exposure of the charged surface with a laser beam 3Y based on an image signal to form an electrostatic latent image. The apparatus 3, the developing device 4Y that develops the electrostatic latent image with toner, the primary transfer roll 5Y that transfers the developed toner image onto the intermediate transfer belt 20, and the toner remaining on the surface of the photoreceptor 1Y after the primary transfer are removed. Cleaning devices 6Y are sequentially arranged.

  The primary transfer roll 5Y is disposed inside the intermediate transfer belt 20, and is provided at a position facing the photoreceptor 1Y. Further, a bias power source (not shown) for applying a primary transfer bias is connected to each of the primary transfer rolls 5Y, 5M, 5C, and 5K.

  Next, an operation for forming a yellow image in the first unit 10Y will be described. The surface of the photoreceptor 1Y is charged by the charging roll 2Y. By exposing the surface of the photoreceptor 1Y with the laser beam 3Y from the exposure device 3, an electrostatic latent image is formed on the surface of the photoreceptor 1Y. Further, the electrostatic latent image on the photoreceptor 1Y is visualized as a toner image by the developing device 4Y. The toner image developed on the photoreceptor 1Y is conveyed to a predetermined primary transfer position, and a primary transfer bias is applied to the primary transfer roll 5Y, so that the toner image on the photoreceptor 1Y is transferred to the intermediate transfer belt 20. Transcribed above. The toner remaining on the photoreceptor 1Y is removed and collected by the cleaning device 6Y.

  In the second to fourth units 10M, 10C, and 10K, toner images corresponding to the respective colors are formed on the photoreceptors 1M, 1C, and 1K by the same operation as that of the first unit 10Y. The intermediate transfer belt 20 onto which the yellow toner image has been transferred by the first unit 10Y is sequentially conveyed to the second to fourth units 10M, 10C, and 10K, and the photoreceptors 1M, The toner images of the colors 1C and 1K are superimposed and transferred multiple times.

  The intermediate transfer belt 20 onto which four color toner images have been transferred in multiples is disposed on the intermediate transfer belt 20, a support roll 24 that contacts the inner surface of the intermediate transfer belt 20, and an image holding surface side of the intermediate transfer belt 20. It moves to the secondary transfer section 23 composed of the next transfer roll 26. Here, the support roll 24 and the secondary transfer roll 26 are examples of an image forming unit. On the other hand, a recording paper P as an example of a medium is stored in the storage unit 32, and a contact portion between the secondary transfer roll 26 and the intermediate transfer belt 20 is previously provided by a paper feed roll 34 and a plurality of transport rolls 36. Paper is fed at a predetermined timing. The toner image on the intermediate transfer belt 20 is transferred onto the recording paper P by applying a secondary transfer bias to the support roll 24. Thereafter, the recording paper P is fed into a nip portion where the fixing roll 52 and the opposing member 54 in the fixing device 28 are pressed against each other, and the toner image is fixed on the recording paper P, thereby forming a fixed image. The recording paper P on which the color image has been fixed is carried out toward the discharge unit, and a series of color image forming operations is completed.

<Configuration of fixing device>
Next, the fixing device 28 including the fixing roll 52 according to one embodiment will be described.

  FIG. 2 is a sectional view of the fixing roll 52 according to the embodiment. Further, FIG. 3 is a cross-sectional view showing a state in which the surface side of the fixing roll 52 is developed. As shown in FIGS. 2 and 3, the fixing roll 52 includes a cylindrical base 60, an elastic layer 62 formed around the base 60, and an adhesive layer 64 on the surface of the elastic layer 62. And a surface layer 66 provided. That is, the surface layer 66 constitutes the outermost surface of the fixing roll 52 and is adhered to the surface of the elastic layer 62 by the adhesive layer 64.

  As the base material 60, for example, a metal base material (core metal) such as nickel, aluminum, or stainless steel is used. Although not shown, a heat source for fixing the toner image on the recording paper P by heating is provided inside the substrate 60. For example, a halogen lamp is used as the heat source.

  As shown in FIG. 3, the elastic layer 62 includes periodic uneven portions 63 on the surface thereof in the axial section (axial section of the fixing roll 52 along the arrow D). The concavo-convex portion 63 has a configuration in which the concave portions 63A and the convex portions 63B are alternately arranged. Here, the uneven part 63 is an example of an uneven part. In FIG. 3, the configuration of the elastic layer 62 of the fixing roll 52 is schematically illustrated for easy understanding. In the present embodiment, the waviness (Wc-t), which is the periodic uneven portion 63 on the surface of the elastic layer 62, is 5 μm or more and 30 μm or less. Here, the swell (Wc-t) is a value measured by Surfcom from Tokyo Seimitsu. Specifically, the swell (Wc-t) was measured using a surfcom manufactured by Tokyo Seimitsu Co., Ltd., filtered centerline swell measurement, measurement length 32 mm, measurement speed 3.00 mm / s, cutoff type: Gaussian, calculation standard: JIS '94 standard, inclination correction: least square curve correction, cut-off wavelength: measured from 0.08 mm to 2.5 mm.

  In the present embodiment, the width (period) of the periodic uneven portion 63 on the surface of the elastic layer 62 is 1 mm or more and 30 mm or less. Specifically, the width (period) of the concavo-convex portion 63 is obtained by cutting the surface of the elastic layer 62 along the axial direction (D direction) and the circumferential direction, and from the concave portion 63A to the convex portion 63B based on the state of the cross section. The width (cycle) is measured at a plurality of locations, and the average value is taken.

  The elastic layer 62 includes a heat resistant elastic material as an example. Examples of the heat resistant elastic material include silicone rubber and fluoro rubber. Examples of the silicone rubber include RTV silicone rubber, HTV silicone rubber, and liquid silicone rubber. Specifically, polydimethyl silicone rubber (MQ), methyl vinyl silicone rubber (VMQ), methyl phenyl silicone rubber (PMQ). ), Fluorosilicone rubber (FVMQ) and the like. Examples of the fluororubber include vinylidene fluoride rubber, ethylene tetrafluoride / propylene rubber, ethylene tetrafluoride / perfluoromethyl vinyl ether rubber, phosphazene rubber, and fluoropolyether.

  The thickness of the elastic layer 62 is, for example, preferably 30 μm or more and 600 μm or less, and more preferably 100 μm or more and 500 μm or less.

  The elastic layer 62 is formed as follows, for example. With the axis of the cylindrical substrate 60 rotated horizontally, the material of the elastic layer (for example, a silicone rubber composition) is flowed down or dropped from the upper part by a nozzle, and the blade is pressed at the lower part. The film is formed to have a predetermined film thickness (for example, 600 μm). Then, the elastic layer 62 is obtained by baking the base material 60 on which the material of the elastic layer is disposed at a predetermined temperature and time (for example, 200 ° C./1 hour). In the present embodiment, by adjusting the diameter of the nozzle, for example, a spiral periodic uneven portion 63 is formed on the surface of the elastic layer 62.

  Since the adhesive layer 64 functions to suppress the occurrence of peeling by adhering the elastic layer 62 and the surface layer 66, in general, in addition to the adhesiveness between the elastic layer 62 and the surface layer 66, the adhesive layer 64 is constant. It is required to have the above strength. Examples of the material for forming the adhesive layer 64 include glycidoxypropyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, glycidoxypropyltrimethoxysilane, glycidoxypropylmethyldiethoxysilane, methacrylate, and the like. Examples include loxypropylmethyldiethoxysilane, methacryloxypropyltriethoxysilane, and allyltriethoxysilane.

  The adhesive layer 64 is preferably formed so as to fill the uneven portion 63 of the elastic layer 62. The thickness of the adhesive layer 64 from the average height of the convex portions 63B of the elastic layer 62 is, for example, preferably 5 μm or more and 50 μm or less, and more preferably 10 μm or more and 40 μm or less.

  The surface layer 66 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, a fluororesin is preferable as the heat-resistant release material. Specific examples of the fluororesin include, for example, tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), polyethylene / tetra Examples include fluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), polychloroethylene trifluoride (PCTFE), and vinyl fluoride (PVF).

  The thickness of the surface layer 66 is, for example, preferably 5 μm or more and 50 μm or less, and more preferably 10 μm or more and 40 μm or less. In the present embodiment, the irregularities 63 having the recesses 63 </ b> A and the projections 63 </ b> B are formed on the surface of the elastic layer 62, so that the irregularities corresponding to the irregularities 63 are formed on the surface 66 </ b> A of the surface layer 66. May come out. In that case, the undulation of the surface 66 </ b> A of the surface layer 66 is smaller than the undulation (Wc−t) of the uneven portion 63 of the elastic layer 62.

  The formation of the surface layer 66 is not particularly limited. For example, a tubular body (tube) manufactured using a heat-resistant release material as a surface layer is decompressed and placed along the inner wall of a cylindrical mold, and then the elastic layer coated with the above adhesive composition The base material 60 provided with 62 is inserted into the mold. Then, after the base material 60 provided with the elastic layer 62 has been inserted into the mold, the decompression is released, and the elastic layer 62 is covered with a tubular body (tube) as the surface layer 66, thereby fixing. A roll 52 is obtained.

  As shown in FIG. 4, the fixing device 28 includes a fixing roll 52 and an opposing member 54 that is pressed against the fixing roll 52. The fixing roll 52 is configured to be rotationally driven in the direction of arrow R1 by a motor (not shown). Although not shown, the facing member 54 includes, as an example, an endless pressure belt, and a pressure unit that is disposed in the pressure belt and contacts the fixing roll 52 with the pressure belt. . When the facing member 54 is pressed against the fixing roll 52, a nip portion N1 where the facing member 54 and the fixing roll 52 come into contact is formed. The pressure belt constituting the facing member 54 is moved in the direction of the arrow R <b> 2 following the rotation of the fixing roll 52.

  FIG. 4 schematically shows the nip portion N1 where the fixing roll 52 and the facing member 54 are pressed against each other. In the present embodiment, at the nip portion N1 where the fixing roll 52 and the facing member 54 are pressed against each other, at least one convex portion 63B on the surface of the elastic layer 62 is disposed along the circumferential direction of the fixing roll 52. Has been.

<Action and effect>
Next, the operation and effect of this embodiment will be described.

  As shown in FIG. 4, the recording paper P is conveyed to the nip portion N <b> 1 where the facing member 54 is pressed against the fixing roll 52. As a result, the toner image T on the recording paper P is heated and pressurized at the nip portion N1, and the toner image T is fixed on the recording paper P.

  The elastic layer 62 of the fixing roll 52 includes a periodic concavo-convex portion 63 including a concave portion 63A and a convex portion 63B on the surface in the axial cross section. In the present embodiment, at the nip portion N1 where the fixing roll 52 and the opposing member 54 are pressed against each other, at least one concave portion 63A and convex portion 63B on the surface of the elastic layer 62 are arranged along the circumferential direction of the fixing roll 52. It is set as the structure. As a result, the shearing force when the recording paper P passes through the nip portion N1 where the fixing roll 52 and the opposing member 54 are pressed against each other is supported by the convex portion 63B, and the shearing (shear) stress is effectively dispersed.

  For this reason, in the fixing roll 52, the peeling between the surface layer 66 and the elastic layer 62 during use of the fixing roll 52 is suppressed as compared with a configuration in which the elastic layer has a smooth surface.

  Further, in the fixing roll 52 described above, the waviness (Wc-t) that is the periodic uneven portion 63 on the surface of the elastic layer 62 is set to 5 μm or more and 30 μm or less. For this reason, in the fixing roll 52 described above, the surface layer 66 and the elastic layer 62 when the fixing roll 52 is used are compared with the case where the waviness (Wc-t) which is the unevenness of the surface of the elastic layer is smaller than 5 μm. Peeling of the elastic layer is suppressed, and the generation of vertical stripes is suppressed as compared with the case where the undulation (Wc-t) which is the unevenness of the surface of the elastic layer is larger than 30 μm.

  Further, in the fixing roll 52 described above, the width (period) of the uneven portion 63 on the surface of the elastic layer 62 is set to 1 mm or more and 30 mm or less. Therefore, in the fixing roll 52 described above, the surface layer 66 and the elastic layer 62 are peeled off when the fixing roll 52 is used, as compared with the case where the width (period) of the irregularities on the surface of the elastic layer is smaller than 1 mm. As a result, the occurrence of vertical stripes is suppressed as compared with the case where the width (period) of the unevenness on the surface of the elastic layer is larger than 30 mm.

  Further, in the fixing device 28 and the image forming apparatus 40, the fixing roll 52 is moved when the facing member 54 is brought into pressure contact with the fixing roll 52 as compared with a configuration in which a fixing roll having a smooth surface of the elastic layer is provided. Thus, the service life of the fixing roll 52 is reduced.

  In the fixing roll 52, the thickness of the elastic layer 62, the thickness of the adhesive layer 64, the thickness of the surface layer 66, and the like can be changed.

  Further, although the present invention has been described in detail with respect to specific embodiments, the present invention is not limited to such embodiments, and various other embodiments are possible within the scope of the present invention. It is clear to the contractor.

  Next, an experiment will be described in which an image forming state is evaluated when an image is formed by an image forming apparatus using a plurality of types of fixing rolls having different elastic layer undulations.

<Example 1>
[Preparation of silicone rubber composition]
In advance, 40 parts by mass of 100 parts by mass of dimethylpolyorganosiloxane (vinyl group content 0.08 mmol / g, viscosity (25 ° C.) 30,000 Pa · s) was blended in a kneader, and alumina fine powder (Na 100 parts by mass of an ion content of 10 ppm and a volume average particle diameter of 3 μm) were blended. These were kneaded at 150 ° C. for 2 hours, then diluted with 60 parts by mass of the remaining dimethylpolyorganosiloxane, and further a trimethylsiloxy group-capped dimethylsiloxane / methylhydrodienesiloxane copolymer (silicon atom-bonded hydrogen atom). Content 3 mmol / g, Viscosity (25 ° C.) 5 mPa · s) 4.0 parts by mass, chloroplatinic acid-divinyltetramethyldisiloxane complex as catalyst, 10 ppm as platinum content, 1-ethynyl-1- as curing retarder A silicone rubber composition was prepared by mixing 0.1 parts by mass of cyclohexanol and 2 parts by mass of ferric oxide (Fe ₃ O ₄ ) as uniformly as possible.

[Formation of elastic layer body]
The elastic layer body was molded using the silicone rubber composition described above. The molding method is such that the core metal is placed sideways against a core metal (for example, aluminum material) as a cylindrical base material to which a primer (manufactured by Dow Corning Toray, DY39-051A / B) is applied in advance. In this state, the silicone rubber composition was dropped from the upper part with a nozzle and pressed with a blade at the lower part to form a predetermined film thickness (600 μm). Thereafter, the core metal on which the silicone rubber composition was formed was baked at 200 ° C./1 hour to obtain an elastic layer body.

  In Example 1, when the silicone rubber composition is dropped from above by a nozzle, by selecting the size of the nozzle diameter, periodic irregularities (uneven portions) are formed on the surface of the elastic layer body. In Example 1, when the surface waviness of the elastic layer was measured by the above-described measurement method, the surface waviness of the elastic layer was 5 μm as shown in FIG.

(Preparation of adhesive composition)
40 parts by mass of 100 parts by mass of dimethylpolyorganosiloxane (vinyl group content 0.08 mmol / g, viscosity (25 ° C.) 30,000 Pa · s) is mixed in a kneading apparatus, and alumina fine powder (containing Na ions) The amount was 10 ppm, and the volume average particle diameter was 3 μm). These were kneaded at 150 ° C. for 2 hours, then diluted with 60 parts by mass of the remaining dimethylpolyorganosiloxane, and further a trimethylsiloxy group-capped dimethylsiloxane / methylhydrodienesiloxane copolymer (silicon atom-bonded hydrogen atom). Content 3 mmol / g, viscosity (25 ° C.) 5 mPa · s) 2.0 parts by mass, chloroplatinic acid-divinyltetramethyldisiloxane complex as catalyst, 10 ppm as platinum content, 1-ethynyl-1- as curing retarder A mixture in which 0.1 part by mass of cyclohexanol and 2 parts by mass of ferric oxide (Fe ₃ O ₄ ) were mixed as uniformly as possible was 100 parts by mass, and glycidoxypropyltrimethoxysilane was added to this mixture. 5 parts by weight were added. The mixture to which glycidoxypropyltrimethoxysilane was added was diluted to 40% by mass with n-heptane to obtain an adhesive composition.

(Fixing roll production)
After applying the above-mentioned adhesive composition to the above-mentioned elastic layer at a thickness of 20 μm, setting the PFA tube along the inner wall of the cylindrical mold under reduced pressure, and then applying the above-mentioned adhesive composition The elastic layer body was inserted into the mold. Then, after the elastic layer body was inserted into the mold, the decompression was released, and the elastic layer body was covered with the PFA tube to obtain a fixing roll.

[Measurement / Evaluation]
The fixing roll obtained by the above method is mounted on an image forming apparatus (manufactured by Fuji Xerox Co., Ltd., color copying machine Docu Center-3 C3300), and after a paper feeding test of 150,000 sheets, magenta halftone 50% Image quality samples were collected and visually evaluated from the following viewpoints. The results are shown in FIG. The image quality evaluation criteria are as follows.
“◎” indicates that the image quality color point due to peeling has not occurred.
“◯” indicates that the image quality color point partially occurred (no problem in actual use).
“Δ” indicates that the image quality color point is slightly generated (this may cause a problem in actual use).
“X” indicates that an image quality color point has occurred (there is a problem in actual use).

<Examples 2 to 5>
A fixing roll was produced in the same manner as in Example 1 except that the undulation of the produced fixing roll was as shown in FIG. In Examples 2 to 5, when the silicone rubber composition was dropped from above by a nozzle, a fixing roll having different elastic layer undulations was produced by changing the size of the nozzle diameter. At that time, for example, when the nozzle diameter is reduced, the undulation of the elastic layer is reduced.

<Comparative Example 1>
A fixing roll was produced in the same manner as in Example 1 except that the surface undulation of the produced fixing roll was as shown in FIG. 5, and the evaluation was carried out in the same manner as in Example 1. In Comparative Example 1, fixing rolls having different undulations on the surface of the elastic layer were prepared by changing the size of the nozzle diameter when the silicone rubber composition was dropped from above with a nozzle.

  As shown in FIG. 5, in Example 5, the occurrence of image quality color points due to peeling of the fixing roll was not confirmed, but the occurrence of vertical streaks due to the undulation of the elastic layer was confirmed in the initial stage. Therefore, it can be seen that when the surface waviness (Wc-t) of the elastic layer is 5 μm or more and 30 μm or less, the image quality color point and the vertical streak are not likely to occur due to peeling of the fixing roll.

10Y, 10M, 10C, 10K Image forming unit (an example of an image forming unit)
20 Intermediate transfer belt (an example of an image forming unit)
24 Support roll (an example of an image forming unit)
26 Secondary transfer roll (an example of an image forming unit)
28 Fixing Device 40 Image Forming Device 52 Fixing Roll 54 Opposing Member 60 Base Material 62 Elastic Layer 63 Concavity and convexity (an example of irregularity)
63A Concave part 63B Convex part 64 Adhesive layer 66 Surface layer P Recording paper (an example of medium)

Claims (5)

A cylindrical substrate;
An elastic layer formed around the base material and provided with periodic irregularities on the surface in the axial section;
A surface layer provided on the surface of the elastic layer via an adhesive layer;
A fixing roll.   2. The fixing roll according to claim 1, wherein the waviness Wc-t, which is a periodic unevenness on the surface of the elastic layer, is 5 μm or more and 30 μm or less.   The fixing roll according to claim 1, wherein a width of the periodic unevenness on the surface of the elastic layer is 1 mm or more and 30 mm or less. A fixing roll according to any one of claims 1 to 3,
An opposing member pressed against the fixing roll;
A fixing device. An image forming unit for forming a toner image on a medium;
The fixing device according to claim 4, wherein the fixing device fixes the toner image formed on the medium.
An image forming apparatus.

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