JP2004271572A - Rotating body for fixing, fixing device, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To stably fix a good-quality image by securing releasing property so that offset is prevented from occurring and also enhancing wear and abrasion resistance. <P>SOLUTION: A releasing layer 41 formed on an elastic layer 40 with which the surface of the metallic substance 39 of a fixing roller 31 is covered is formed of two layers, that is, a substance side releasing layer 41a and a surface releasing layer 41b. The layer 41a is formed of PFA and the layer 41b is formed of FEP, and a boundary between the layers 41a and 41b has fine peak and valley structure, whereby the offset is prevented from occurring by enhancing the releasing property to toner by the FEP of the layer 41b when a toner image 35 transferred to the recording paper 34 medium is fixed. Even when many sheets of recording paper 34 are made to pass and the FEP of the layer 41b is worn, a part of the PFA of the layer 41a having the fine peak and valley structure appears on the surface, so that the wear and abrasion resistance is enhanced. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

【００２８】
前記表に示す離型性の評価結果の２重丸印はオフセットなしで、定着ローラ３１の汚れなしの場合、丸印は実用上問題となるオフセットなして、定着ローラ３１の汚れなしの場合、三角印は実用上問題となるオフセットはないが定着ローラ３１に汚れがある場合、ばつ印は実用上問題となるオフセットがある場合を示す。また、耐摩耗性の評価結果は、丸印は定着ローラ３１に疵がないか、摩耗と疵はめられるが、画像上問題ない場合、三角印はハーフトーン画像で軽微な疵が発生した場合、ばつ印は定着ローラ３１に疵等が発生して画像スジ等の欠陥が認められた場合を示す。前記表に示すように、本発明の場合はいずれも比較例と比べて定着ローラ３１の寿命を長くすることができるとともに良質な画像を安定して形成することができた。
【００２９】
前記説明では定着ユニット１７に定着ローラ３１を使用した場合について示したが、図６の構成図に示すように、加熱ローラ４３と駆動ローラ４４に巻き回された定着ベルト４５を、図３（ｂ）の部分断面図に示すように、ポリイミドや金属箔のエンドレスベルト基体４６の表面に弾性層４０と離型層４１を形成し、離型層４１を、ＰＦＡ又は無機充填剤を充填したＰＦＡの基体側離型層４１ａとＦＥＰの表面離型層４１ｂの２層で形成し、基体側離型層４１ａと表面離型層４１ｂの界面を微細な山谷構造にすることにより、定着ベルト４５のオフセットを防止して寿命を長くすることができる。
【００３０】
【発明の効果】
この発明は以上説明したように、定着用回転体の離型層を、基体側離型層と表面離型層の２層で形成し、基体側離型層をＰＦＡで形成し、表面離型層をＦＥＰで形成し、基体側離型層と表面離型層の界面を微細な山谷構造にすることにより、記録媒体に転写された現像剤像を定着したとき、表面離型層のＦＥＰで現像剤に対する離型性を高めてオフセットが生じることを防ぐことができる。また、大量の記録媒体を通紙して、表面離型層のＦＥＰが磨耗しても、微細な山谷構造をした基体側離型層のＰＦＡの一部が表面に現れて耐磨耗性を高めることができる。さらに、基体側離型層のＰＦＡの一部が表面に現れても、表面離型層のＦＥＰの大部分が残っているから離型性を保つことができる。
【００３１】
また、基体側離型層を形成するＰＦＡに無機充填剤を充填することにより、基体側離型層の溶融流動性をより低くして基体側離型層と表面離型層の界面の微細な山谷構造を深くすることができ、長期間安定して離型性を保つことができる。
【００３２】
さらに、基体側離型層を形成するＰＦＡの平均粒径を１０〜３０μｍとし、表面離型層を形成するＦＥＰの平均粒径をＰＦＡの平均粒径より小さくすることにより、基体側離型層と表面離型層の界面の微細な山谷構造を安定して形成し、離型性と体磨耗性を高めることができる。
【００３３】
また、基体を金属からなるローラで形成し、２層構造の離型層を、ローラを保持する軸受部まで形成し、ローラの回転に対する負荷を低減するとともに、ローラの軸受部における磨耗を低減することができる。
【００３４】
この定着用回転体を定着装置に使用することにより、良質な画像を長期間定着するすることができる。
【００３５】
また、この定着装置を電子写真方式の画像形成装置に使用することにより、良質な画像を長期間形成することができる。
【図面の簡単な説明】
【図１】この発明のデジタル複写機の構成図である。
【図２】定着ユニットの構成を示す断面図である。
【図３】離型層の構成を示す部分断面図である。
【図４】離型層の範囲を示す側面図である。
【図５】離型層の製造方法を示す部分断面図である。
【図６】他の定着ユニットの構成図である。
【符号の説明】
１；デジタル複写機、２；複写機本体、３；ＡＤＦ、４；自動仕分け装置、
５；原稿読取ユニット、６；書込ユニット、７；エンジン部、
８；給紙ユニット、１４；画像形成ユニット、１５；１次転写ユニット、
１６；２次転写ユニット、１７；定着ユニット、１８；感光体、
３１；定着ローラ、３９；基体、４０；弾性層、４１；離型層、
４１ａ；基体側離型層、４１ｂ；表面離型層。[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fixing rotator, a fixing device, and an image forming apparatus for fixing a toner image transferred to a recording medium by an electrophotographic copying machine, a printer, or the like, and more particularly to an improvement in releasability and durability.
[0002]
[Prior art]
A fixing device of a heat roller type is often used as a fixing device for fixing a toner image transferred onto a recording sheet in an image forming apparatus such as a copying machine using an electrophotographic method. Have been. This fixing device has a heat source inside, and presses and rotates a fixing roller and a pressure roller formed of a material having a surface releasable from toner, for example, silicone rubber or fluororesin, and forms a pressure contact portion between both rollers. The unfixed toner image on the recording paper passing through the nip is fixed by heating and pressing. In this heat roller type fixing device, since the surface of the fixing roller and the toner image on the recording paper come into contact with each other under pressure, the thermal efficiency at the time of fusing the toner image onto the recording paper is extremely good, and the fixing can be performed quickly. This is very effective in a high-speed electrophotographic copying machine or the like. However, since the surface of the fixing roller and the toner image are in contact with each other in a molten state and under pressure, an offset phenomenon occurs in which a part of the toner image adheres to the surface of the fixing roller and is transferred, thereby soiling the next recording paper. Preventing toner from adhering to the surface of the fixing roller is one of the essential conditions of the heat roller fixing method.
[0003]
Further, in the case of full color, color reproduction is performed using three primary color toners of yellow, magenta, and cyan, or a four-color toner obtained by adding black toner thereto. Is fixed on paper or fixed on an overhead projector sheet (OHT), but color reproducibility and transparency must be satisfied. For this reason, it is required that the toner layer is sufficiently melted and the image surface is smoothed, and for the purpose of preventing offset, for example, a method of supplying a fixing roller with, for example, silicone oil and uniformly covering the roller with the fixing roller is currently used. It has become.
[0004]
Although this method is extremely effective in preventing toner offset, it has a disadvantage that the fixing device is complicated because a device for supplying an anti-offset liquid is required, and is small and inexpensive. It is an inhibitor in designing the system. Furthermore, in a transparency film (OHP film) using an overhead projector, which is increasingly required for presentation, unlike paper, the oil absorption capacity is low, so that the stickiness of the OHP film surface after fixing becomes a problem. I have. From such a background, there is a strong demand for a fixing device capable of fixing without oil or with a small amount of applied oil.
[0005]
For this reason, as disclosed in Patent Document 1, for example, it has been proposed to add a solid silicone varnish, a higher fatty acid or a higher alcohol variety wax as a release agent to the toner. Also, on the outer surface of the fixing roller, a material having a high mold release such as a fluororesin such as perfluoroalkoxy fluororesin PFA, polytetrafluoroethylene PTFE or polytetrafluoroethylene 6-fluoropropylene copolymer FEP is formed to offset. It is preventing.
[0006]
[Problems to be solved by the invention]
However, when a certain amount or more of a release agent such as a solid silicone varnish or a higher fatty acid or a higher alcohol various waxes is added to the toner, the release agent is released from the toner during development and adheres to a photoreceptor or a carrier. The disadvantage is that spent occurs.
[0007]
Further, when a release layer is formed on the surface of the fixing roller with fluororesin or the like, pure fluororesin does not have such a high toughness in terms of abrasion resistance, and thus has a disadvantage that its life is short. The wear resistance can be improved by adding a relatively hard inorganic filler such as silicon nitride, aluminum nitride, alumina, silica, carbon, mica, and molybdenum disulfide. If the amount is too small, the effect of improving the abrasion resistance is not sufficient, and if the amount of the inorganic filler mixed is increased, the releasability and the surface smoothness are deteriorated, and the offset prevention effect is reduced.
[0008]
The present invention improves such disadvantages, and secures a releasability with a small amount of a release agent, prevents an offset from occurring, improves abrasion resistance, and can stably fix a high-quality image. It is an object of the present invention to provide a rotating body, a fixing device, and an image forming apparatus.
[0009]
[Means for Solving the Problems]
The fixing rotator of the present invention covers an elastic layer on a substrate surface, has a release layer on the surface of the elastic layer, and records a developer transferred to a recording medium by heating with a heat source provided inside. In a fixing rotator for fixing to a medium, a release layer is formed of two layers, a substrate-side release layer and a surface release layer, the substrate-side release layer is formed of PFA, and the surface release layer is formed of FEP. After forming, the interface between the substrate side release layer and the surface release layer has a fine peak-valley structure, and when the developer image transferred to the recording medium is fixed, the releasability of the surface release layer to the developer is improved by the FEP. To prevent offset from occurring. Also, even if a large amount of recording medium is passed through and the FEP of the surface release layer is worn, a part of the PFA of the substrate-side release layer having a fine valley structure appears on the surface to reduce wear resistance. Enhance. Furthermore, even if a part of the PFA of the release layer on the substrate side appears on the surface, most of the FEP of the surface release layer remains, so that the releasability is maintained.
[0010]
Further, PFA forming the base-side release layer is filled with an inorganic filler to lower the melt fluidity to deepen the fine valley structure at the interface between the base-side release layer and the surface release layer.
[0011]
Further, the average particle size of PFA forming the substrate-side release layer is set to 10 to 30 μm, and the average particle size of FEP forming the surface release layer is made smaller than the average particle size of PFA, so that A fine peak-valley structure at the interface of the surface release layer is formed stably.
[0012]
In addition, the base is formed of a metal roller, and the release layer having the two-layer structure is formed up to the bearing for holding the roller, thereby reducing the load on the rotation of the roller.
[0013]
The fixing device according to the present invention is characterized in that the fixing device includes the fixing rotating body and fixes a high-quality image for a long period of time.
[0014]
An image forming apparatus according to the present invention includes the fixing device and forms a high-quality image for a long period of time.
[0015]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a block diagram of a digital copying machine according to the present invention. The digital copying machine 1 has a copying machine main body 2, an automatic document feeder (hereinafter, ADF) 3, and an automatic sorting device 4. The copying machine main body 2 includes a document reading unit 5, a writing unit 6, an engine unit 7, and a paper feeding unit 8. The document reading unit 5 has a carriage 9 having a light source and a plurality of mirrors, a lens 10, a CCD 11 and a buffer 12, and scans and reads a document sent by the ADF 3. The writing unit 6 has a laser light source, a polygon mirror, and the like, and emits a laser beam 13 including image information to the engine unit 7. The engine unit 7 includes an image forming unit 14, a primary transfer unit 15, a secondary transfer unit 16, and a fixing unit 17. The image forming unit 14 includes a charging roller 19 disposed around the photoreceptor 18 and an irradiation unit of the laser beam 13 from the writing unit 5 and cyan (C), magenta (M), yellow (Y), and black (K). ), A laser beam 13 is formed on the photoreceptor 18 charged by the charging roller 19 disposed at a small gap from the photoreceptor 18 to form an electrostatic latent image. Then, the formed electrostatic latent image is visualized by the color developing unit 20 to form a toner image. The primary transfer unit 15 has an intermediate transfer belt 22, a primary transfer unit 23, a tension roller 24, a secondary transfer roller 25, a cleaning unit 26, and a reference position sensor 27, and intermediately transfers a toner image formed on the photoconductor 18. The primary transfer is performed on the transfer belt 22. The intermediate transfer belt 22 is formed to be larger than A3, which is the maximum transfer paper size in the digital copying machine 1. When the transfer paper to be used is smaller than A4 size, the intermediate transfer belt 22 holds two toner images. Can be. The intermediate transfer belt 22 is separated from the surface of the photoconductor 18 by a contact / separation mechanism (not shown) except when the toner image on the photoconductor 18 is primarily transferred, and only when the image is primarily transferred to the intermediate transfer belt 22. It is pressed against the surface. The secondary transfer unit 16 secondary-transfers the toner image transferred to the intermediate transfer belt 22 onto recording paper. The fixing unit 17 fixes the toner image transferred on the recording paper by heat and pressure. The paper feed unit 8 has a plurality of paper feed cassettes 28 a to 28 c and a manual feed tray 29, and sends recording paper to the secondary transfer unit 16.
[0016]
The ADF 3 sends a document to be read to the document reading unit 5 and collects the document read by the document reading unit 5. The automatic sorting device 4 has a plurality of sorting bins 30a to 30n, and sorts and discharges recording paper on which an image is formed.
[0017]
When the image forming cycle of the original read by the original reading unit 5 in the digital copying machine 1 is started, if the image to be formed is one color, a toner image is formed on the photoreceptor 18 by the image data of the read original, and the formation is performed. The transferred toner image is primarily transferred to the intermediate transfer belt 22. The secondary transfer unit 16 secondary-transfers the toner image onto recording paper fed in accordance with the leading end of the toner image transferred to the intermediate transfer belt 22. The recording paper on which the toner image has been transferred is sent to the fixing unit 17 and is heated and pressed to be fixed. The recording paper on which the toner image has been fixed is discharged to the automatic sorting device 4. Further, the toner remaining on the intermediate transfer belt 22 is collected by the cleaning unit 26.
[0018]
If the image to be formed has two or more colors, the document is read by the document reading unit 5 based on the detection of the reference mark provided on the intermediate transfer belt 22 by the reference position sensor 27, and the read image data is transmitted to the control unit 100. To the central control unit 101 and stored in the image memory 102. The central control unit 101 forms a first color toner image on the photoconductor 18 based on the sent image data, and primary-transfers the toner image formed on the photoconductor 18 to the intermediate transfer belt 22. Subsequently, the central control unit 101 forms a second color toner image on the photoconductor 18 based on the image data stored in the image memory 102, and primarily transfers the toner image formed on the photoconductor 18 to the intermediate transfer belt 22. The image formation on the photoconductor 18 and the primary transfer on the intermediate transfer belt 22 are repeated for each color. That is, the intermediate transfer belt 22 is rotated twice to form a two-color image, and the intermediate transfer belt 22 is rotated four times to form a full-color image. The transferred toner images are primarily transferred onto the intermediate transfer belt 22 so that the images of the respective colors are superimposed without displacement. After the toner image of a predetermined color has been transferred to the intermediate transfer belt 22, the toner image is secondarily transferred to recording paper fed according to the leading end of the toner image transferred to the intermediate transfer belt 22, and heated by the fixing unit 17. , Pressing and fixing.
[0019]
The fixing unit 17 of the digital copying machine 1 has a fixing roller 31 and a pressure roller 32. The fixing roller 31 has a built-in heater 33 as shown in the sectional view of FIG. 2, and heats and presses the toner image 35 transferred to the recording paper 34 at a nip portion with the pressure roller 32 to fix the toner image 35 on the recording paper 34. I do. After the toner image 35 is fixed, the recording paper 34 is separated from the surface of the fixing roller 31 by the separation claw 36 and is taken out in a predetermined direction. When the fixing roller 31 is heated, the temperature of the fixing roller 31 is detected by a temperature sensor 37 such as a thermistor, and the power supply to the heater 33 is controlled. The toner adhered to the surface of the fixing roller 31 is removed by the cleaning unit 38.
[0020]
The fixing roller 31 has an elastic layer 40 made of, for example, silicone rubber on the surface of a base 39 of a metal roller made of aluminum or the like, and a release layer 41 made of a fluororesin on the surface of the elastic layer 40. The inner surface of the base 39 may be coated with a black body in order to easily absorb the heat of the heater 33. The elastic layer 40 is used for the fixing roller 31 for full color, but may not be used for monochrome. An adhesive layer may be provided between the base 39 and the elastic layer 40 and between the elastic layer 40 and the release layer 41 as necessary.
[0021]
The release layer 41 is formed of two layers, a base release layer 41a and a surface release layer 41b, as shown in FIG. The substrate-side release layer 41a is formed of a perfluoroalkoxy fluororesin PFA, and the surface release layer 41b is formed of, for example, ethylene tetrafluoride-6-propylene propylene copolymer FEP. The interface between the substrate-side release layer 41a and the surface release layer 41b has a fine peak-valley structure, and the surface of the surface release layer 41b is a smooth surface. PFA forming the base-side release layer 41a has lower releasability and fluidity at the time of melting than FEP forming the surface release layer 41b, but has higher abrasion resistance than FEP. Further, since the FEP forming the surface release layer 41b has high melt fluidity, a smooth surface can be obtained only by sintering after coating the FEP, and there is no need for a smoothing process such as polishing unlike PFA. Having.
[0022]
As described above, the release layer 41 of the fixing roller 31 is formed of the base-side release layer 41a and the surface release layer 41b, and the base-side release layer 41a is formed of PFA having abrasion resistance. The release layer 41b is formed of FEP having good releasability, and the interface between the substrate-side release layer 41a and the surface release layer 41b has a fine peak-and-valley structure, so that the toner image 35 transferred to the recording paper 34 is formed. When fixing is performed by applying heat and pressure to the toner, the releasability of the fixing roller 31 from the toner can be enhanced to prevent occurrence of offset. Even if the FEP of the surface release layer 41b is worn by passing a large amount of the recording paper 34, a part of the PFA of the base-side release layer 41a having a fine valley structure appears on the surface, and the wear is reduced. Can be enhanced. In addition, even if a part of the PFA of the substrate-side release layer 41a appears on the surface, most of the FEP of the surface release layer 41b remains, so that the releasability can be maintained.
[0023]
Further, as shown in (b) of the side view of FIG. 4, the release layer 41 formed by the two layers of the base-side release layer 41 a and the surface release layer 41 b is not in the range of the paper passing width W but in (a). By providing up to the range W1 of the sliding bearing 42 for holding the fixing roller 31 as shown in (1), the friction between the fixing roller 31 and the sliding bearing 42 can be reduced, and the load of the motor rotating the fixing roller 31 can be reduced. Can be reduced. Further, the wear of the contact surface of the fixing roller 31 with the sliding bearing 42 is reduced, so that the fixing roller 31 can be used stably for a long time.
[0024]
Next, a method for manufacturing the fixing roller 31 will be described with reference to the cross-sectional view of FIG. After applying a primer to the surface of the base 39, the elastic layer 40 is formed by coating with silicone rubber. A primer is applied to the surface of the elastic layer 40, and PFA having an average particle size of 10 to 30 μm for forming the base-side release layer 41a is applied thereon. Thereafter, the surface release layer 41b is coated with an average particle size of PFA. The release layer 41 is formed by coating and firing an FEP having an average particle diameter smaller than the diameter, for example, 10 μm or less. The coating of PFA and FEP may be performed by spray coating or electrostatic powder coating. When this release layer 41 is formed, PFA has a lower melt fluidity than FEP, so that after firing, PFA keeps a granular state, and the gap between the PFA is filled with FEP, and as shown in FIG. The interface between the release layer 41a and the surface release layer 41b can have a valley structure. In order to form a peak-valley structure at the interface, it is preferable that the average particle size of PFA is 10 to 30 μm. In order to obtain a smooth surface without performing smoothing after firing, the average particle size of FEP is 10 μm. It is desirable to make the following.
[0025]
When the release layer 41 of the fixing roller 31 is formed, the PFA is filled with an inorganic filler such as silicon nitride, aluminum nitride, alumina, silica, carbon, mica, or molybdenum disulfide to melt and flow. Properties can be made lower than that of PFA alone, and the interface between the substrate-side release layer 41a and the surface release layer 41b can have a deeper valley structure.
[0026]
The results of evaluating the offset and abrasion resistance by using the fixing roller 31 in the digital copying machine 1, the case where one layer of FEP is provided for the release layer 41 as a comparative example, and the case of The following table shows the results of evaluating the offset and wear resistance when one layer was provided and when one layer of PFA filled with silica was provided. In the following table, in the present invention 1, when the release layer 41 is formed of the substrate-side release layer 41a of PFA and the surface release layer 41b of FEP, the present invention 2 to the present invention 8 use carbon, mica and disulfide for PFA. A case is shown in which molybdenum, aluminum nitride, silicon nitride, alumina, and silica are respectively filled to form the base-side release layer 41a. The releasability was evaluated by continuously passing 100 ruled line offset charts, and the abrasion resistance was evaluated by passing 20,000 sheets, and the amount of surface scraping.
[0027]
[Table 1]

[0028]
The double circles of the releasability evaluation results shown in the above table have no offset and the fixing roller 31 is not stained, and the circles are practically problematic offsets and the fixing roller 31 is not stained. The triangular marks indicate the case where there is no practically problematic offset but the fixing roller 31 is dirty, and the crosses indicate the case where there is a practically problematic offset. In addition, the results of the evaluation of wear resistance are as follows. A circle indicates that the fixing roller 31 has no flaws, or abrasion and flaws are present, but there is no problem on the image. A triangular mark indicates that a minor flaw occurs in the halftone image. A cross mark indicates a case where a flaw or the like is generated on the fixing roller 31 and a defect such as an image stripe is recognized. As shown in the above table, in the case of the present invention, the life of the fixing roller 31 can be prolonged and the high quality image can be stably formed as compared with the comparative example.
[0029]
In the above description, the case where the fixing roller 31 is used for the fixing unit 17 has been described. However, as shown in the configuration diagram of FIG. 6, the fixing belt 45 wound around the heating roller 43 and the driving roller 44 is used as shown in FIG. As shown in the partial cross-sectional view of (a), an elastic layer 40 and a release layer 41 are formed on the surface of an endless belt base 46 made of polyimide or metal foil, and the release layer 41 is made of PFA or PFA filled with an inorganic filler. The offset of the fixing belt 45 is formed by forming the interface between the substrate-side release layer 41a and the surface release layer 41b into a fine peak-and-valley structure by forming the substrate-side release layer 41a and the FEP surface release layer 41b into two layers. Can be prevented and the life can be extended.
[0030]
【The invention's effect】
As described above, according to the present invention, a release layer of a fixing rotating body is formed of two layers, a substrate-side release layer and a surface release layer, and the substrate-side release layer is formed of PFA. The layer is formed by FEP, and the interface between the substrate side release layer and the surface release layer is formed into a fine peak-valley structure. An offset can be prevented by increasing the releasability of the developer. Also, even if a large amount of recording medium is passed through and the FEP of the surface release layer is worn, a part of the PFA of the substrate-side release layer having a fine valley structure appears on the surface to reduce wear resistance. Can be enhanced. Furthermore, even if a part of the PFA of the substrate-side release layer appears on the surface, most of the FEP of the surface release layer remains, so that the releasability can be maintained.
[0031]
Further, by filling the PFA forming the base-side release layer with an inorganic filler, the melt fluidity of the base-side release layer is lowered, and the fine interface at the interface between the base-side release layer and the surface release layer is reduced. The valley structure can be deepened, and the releasability can be stably maintained for a long time.
[0032]
Further, by setting the average particle size of PFA forming the base-side release layer to 10 to 30 μm and making the average particle size of FEP forming the surface release layer smaller than the average particle size of PFA, And a fine valley structure at the interface between the surface and the release layer can be formed stably, and the release properties and body wear properties can be enhanced.
[0033]
Further, the base is formed by a roller made of metal, and a release layer having a two-layer structure is formed up to a bearing for holding the roller, thereby reducing a load on the rotation of the roller and reducing abrasion in the bearing of the roller. be able to.
[0034]
By using the fixing rotator in a fixing device, a high-quality image can be fixed for a long period of time.
[0035]
Further, by using this fixing device in an electrophotographic image forming apparatus, a high-quality image can be formed for a long period of time.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a digital copying machine according to the present invention.
FIG. 2 is a cross-sectional view illustrating a configuration of a fixing unit.
FIG. 3 is a partial cross-sectional view illustrating a configuration of a release layer.
FIG. 4 is a side view showing a range of a release layer.
FIG. 5 is a partial cross-sectional view illustrating a method for manufacturing a release layer.
FIG. 6 is a configuration diagram of another fixing unit.
[Explanation of symbols]
1; digital copying machine; 2; copying machine body; 3; ADF; 4;
5; document reading unit, 6; writing unit, 7; engine unit,
8; paper feed unit; 14; image forming unit; 15; primary transfer unit;
16; secondary transfer unit, 17; fixing unit, 18; photoconductor,
31; fixing roller, 39; base, 40; elastic layer, 41; release layer,
41a: Base-side release layer, 41b: Surface release layer.

Claims (6)

A fixing rotator that covers a substrate surface with an elastic layer, has a release layer on the surface of the elastic layer, and fixes the developer transferred to the recording medium by heating with a heat source provided therein to the recording medium. ,
The release layer is formed of two layers, a substrate-side release layer and a surface release layer, the substrate-side release layer is formed of PFA, and the surface release layer is formed of FEP. A fixing rotating body characterized in that an interface between the layer and the surface release layer has a fine valley structure. 2. The fixing rotating body according to claim 1, wherein an inorganic filler is filled in the PFA forming the base-side release layer. The average particle size of PFA forming the base-side release layer is 10 to 30 μm, and the average particle size of FEP forming the surface release layer is smaller than the average particle size of PFA. Rotating body for fixing. 4. The fixing rotating body according to claim 1, wherein the base is formed by a roller made of metal, and the release layer having the two-layer structure is formed up to a bearing portion that holds the roller. 5. A fixing device comprising the fixing rotating body according to claim 1. An image forming apparatus comprising the fixing device according to claim 5.

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