JP2006071962A - Manufacturing method of fixing member, fixing member, and fixing apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of fixing member capable of realizing the thinning of an elastomer layer without producing a damage of such an extent as to deteriorate the quality of a fixed image on the surface with regard to the fixing member having outer diameters different in the axial direction. <P>SOLUTION: The manufacturing method of fixing member comprises a process of arranging a resin tube along the inner surface of the resin sleeve on the inner part of a cylindrical mold into which a cylindrical resin sleeve made of resin is inserted; a process of arranging a core metal, a process of pouring liquid rubber; a process of molding a roller member by curing the liquid rubber; and a process of releasing the roller member from a mold. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method of manufacturing a fixing member used for a fixing device that performs image fixing in an image forming apparatus such as a copying machine or a printer.

  In an image forming apparatus such as a copying machine or a printer using an electrophotographic system, for example, a photosensitive member (photosensitive drum) formed in a drum shape is uniformly charged, and the photosensitive drum is controlled based on image information. An electrostatic latent image is formed on the photosensitive drum by exposure with the exposed light. The electrostatic latent image is converted into a visible image (toner image) with toner, and the toner image is transferred onto the recording paper from the photosensitive drum, and then the toner image is fixed on the recording paper with a fixing device.

  A fixing device used in such an image forming apparatus includes a heat source inside a cylindrical metal core, and is formed by laminating a heat-resistant elastic layer on the metal core and a release layer on the outer peripheral surface thereof. The fixing roll is press-fitted to the fixing roll, and is formed by laminating a heat-resistant elastic body layer on the metal core and a release layer made of a heat-resistant resin film or a heat-resistant rubber film on the outer peripheral surface thereof. It consists of a pressure roll. Then, the recording paper carrying the unfixed toner image is passed between the fixing roll and the pressure roll, and the unfixed toner image is heated and pressed to thereby form the toner image on the recording paper. It has become established.

  As described above, in the fixing member such as a fixing roll and a pressure roll used in the fixing device, particularly with the spread of the color image forming apparatus, an elastic body layer for enhancing the image quality of the fixed image and the toner offset are suppressed. Therefore, the release layer is an essential component. In recent years, in addition to the viewpoints of improving the image quality and suppressing toner offset, there is a demand for shortening the time (warm-up time) until the fixing roll is raised from room temperature to a fixable temperature and reducing power consumption. Is also a big one. Therefore, particularly in the fixing roll, it is required to form an elastic body layer that acts as a heat insulator against the heat from the heat source provided in the fixing roll as thin as possible.

  Here, as a conventional technique in which the elastic body layer of the fixing roll is a thin layer, a thickness of 0.15 to 0.4 mm and a rubber hardness of 1 to 45 on a core metal having a thickness of 0.5 to 2.5 mm. There is a technique relating to a fixing roll in which a rubber layer of 0 ° is formed and a thin layer of a fluororesin tube having a thickness of 20 to 50 μm is formed thereon (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 10-254278 (page 3-4)

  By the way, in the fixing roll, the outer diameter of the fixing roll is a shaft so as to apply a tensile force in the width direction to the recording paper so that the recording paper does not wrinkle when the recording paper passes through the nip portion. It is often formed in a so-called “flare shape” that is relatively small at the center in the direction and relatively large at both ends. Further, as a method for manufacturing the fixing roll, generally, a core metal is coaxially installed in a cylindrical mold, and a heat-resistant rubber such as silicone rubber is provided in the gap between the cylindrical mold and the core metal. A method of injecting, curing, cooling, and demolding is employed. When the elastic layer is formed thick, the heat shrink amount of the heat-resistant rubber after cooling is large, so when removing the mold, the inner surface of the cylindrical mold and the elastic body of the fixing roll Sufficient voids can be secured between the layers. Therefore, even when the fixing roll is formed in a flare shape in which the outer diameter of both ends is larger than that of the center portion, when removing the mold, the inner surface of the cylindrical mold and the surfaces of both ends of the molded elastic layer are formed. There was almost no rubbing between them, and pull-out scratches did not occur on the surfaces of both ends.

  However, when trying to reduce the thickness of the elastic layer of the fixing roll, the flare-shaped fixing roll has a small amount of heat shrinkage of the elastic layer after cooling. A sufficient gap cannot be secured between the inner surface of the mold and the elastic layer of the fixing roll. Therefore, when the mold is removed, the inner surface of the cylindrical mold and the both end surfaces of the elastic layer having an outer diameter larger than that of the central portion are rubbed, and pulling scratches are generated on both end surfaces of the fixing roll. There was a case. When such a flaw is generated on the surface of the fixing roll, the toner on the recording paper is offset and fixed to the surface, which may cause deterioration in the quality of the fixed image.

  Accordingly, the present invention has been made to solve the technical problems as described above, and an object of the present invention is to reduce the quality of a fixed image on the surface of a fixing member having a different outer diameter in the axial direction. It is to realize a thin layer of the elastic body layer without causing a degree of damage.

  For this purpose, the method for manufacturing a fixing member according to the present invention includes a resin tube disposed inside a cylindrical mold in which a cylindrical resin sleeve formed of resin is fitted, along the inner surface of the resin sleeve. A step of arranging a cored bar coaxially with the mold and the resin sleeve, a step of injecting liquid rubber into a gap between the cored bar and the resin tube, and a liquid rubber The method includes a step of molding a roll member in which a core metal and a resin tube are bonded via a cured rubber, and a step of removing the roll member from the mold.

  Here, the method for manufacturing a fixing member according to the present invention may further include a step of reducing the pressure between the resin sleeve and the resin tube, and bringing the resin tube into close contact with the inner surface of the resin sleeve. In addition, the resin sleeve may be characterized by having a linear expansion coefficient of 5 × 10 −5 (/ ° C.) or more, and in particular, the resin sleeve may be formed of a fluororesin. In addition, the resin tube may be characterized in that the inner surface is pre-bonded. Further, the liquid rubber may be an addition reaction type silicone rubber.

Further, the present invention is regarded as a fixing member, and the fixing member of the present invention is a fixing member molded using a cylindrical mold, and has a core metal and a thickness of 1 mm or less formed on the core metal. A heat-resistant elastic body layer and a release layer coated on the surface of the heat-resistant elastic body layer, and the release layer has a smooth surface with an arithmetic average roughness Ra ≦ 0.02 μm, or an arithmetic average It is characterized in that it is formed by a surface composed of a smooth portion having a roughness Ra ≦ 0.02 μm and a concave portion having a maximum height Rmax ≦ 4.0 μm.
Here, the heat-resistant elastic layer may be characterized in that the thickness is different in the axial direction, and in particular, the heat-resistant elastic layer has a relatively thin thickness at the center in the axial direction, Can be formed relatively thick. The release layer can be formed to a thickness of 100 μm or less. Further, the release layer may be formed of any one of polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, and tetrafluoroethylene-hexafluoropropylene copolymer.

Further, the present invention is regarded as a fixing device, and the fixing device of the present invention is a fixing device for fixing a toner image carried on a recording material, and can be moved while being in contact with a fixing member having a heat source and a fixing member. The fixing member is formed on the cored bar and has a thickness of 1 mm or less, a relatively small thickness at the center in the axial direction, and a thickness at both ends. Is coated with the surface of the heat-resistant elastic layer and the surface of the heat-resistant elastic layer, and the surface is a smooth surface with an arithmetic average roughness Ra ≦ 0.02 μm, or an arithmetic average roughness Ra ≦ It is characterized by comprising a release layer formed by a surface comprising a 0.02 μm smooth portion and a recess having a maximum height Rmax ≦ 4.0 μm.
Here, the pressure member is disposed inside the belt member that is movable while being in contact with the fixing member, and the recording material is placed between the fixing member and the belt member by pressing the belt member against the fixing member. And a pressure member that forms a passing nip portion.

  As an effect of the present invention, in a fixing member having a different outer diameter in the axial direction such as a flare shape, the elastic layer can be thinned without causing damage on the surface to the extent that the quality of the fixed image is deteriorated. Can do. Also, by realizing a thin elastic layer, it is possible to shorten the warm-up time and reduce the power consumption, and at the same time, it is possible to form a high-quality fixed image.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.
FIG. 1 is a schematic configuration diagram illustrating a fixing device to which the exemplary embodiment is applied. A fixing device 1 shown in FIG. 1 has a function of fixing a toner image transferred to a paper P as a recording material (recording paper) to the paper P in an electrophotographic image forming apparatus such as a copying machine or a printer. is doing. As shown in FIG. 1, the fixing device 1 includes a fixing roll 61 as an example of a rotating member, an endless belt 62 as an example of a belt member, and a pressure pressed from the fixing roll 61 via the endless belt 62. A main part is constituted by a pressure pad 64 as an example of a member.

The fixing roll 61 is a cylindrical roll, is rotatably supported, and rotates in the arrow A direction at a predetermined surface speed.
Inside the fixing roll 61, for example, a halogen heater 66 having a rating of 600 W is disposed as a heat source. On the other hand, a temperature sensor 69 is disposed in contact with the surface of the fixing roll 61. A control unit (not shown) of the image forming apparatus controls the lighting of the halogen heater 66 based on the temperature measurement value by the temperature sensor 69, and the surface temperature of the fixing roll 61 becomes a predetermined set temperature (for example, 175 ° C.). It is adjusted to maintain.

The endless belt 62 is an endless belt without a seam, and includes a pressure pad 64 and a belt guide member 63 disposed inside the endless belt 62, and edge guide members 80 ( It is rotatably supported by the latter stage (see FIG. 2). Then, it is disposed so as to be pressed against the fixing roll 61 at the nip portion N, and rotates following the fixing roll 61.
Here, FIG. 2 is a configuration diagram illustrating a configuration in which the endless belt 62 is supported, and shows one end region of the fixing device 1 viewed from the downstream side in the conveyance direction of the paper P.
As shown in FIG. 2, edge guide members 80 are disposed at both ends of the holder 65 disposed inside the endless belt 62. The edge guide member 80 is provided on the outer side of the belt traveling guide portion 801 having a cylindrical shape in which a notch is formed in a portion corresponding to the nip portion N and the vicinity thereof, that is, a C-shaped cross section, A flange portion 802 formed with an outer diameter larger than the outer diameter of the endless belt 62 and a holding portion 803 provided outside the flange portion 802 for positioning and fixing the edge guide member 80 to the fixing device 1 main body. It is configured.

At both ends of the endless belt 62, the inner peripheral surfaces of both ends are supported by the outer peripheral surface of the belt traveling guide portion 801 except for the nip portion N and the vicinity thereof, and the endless belt 62 is supported by the outer periphery of the belt traveling guide portion 801. Rotate along the surface. Accordingly, the belt traveling guide portion 801 is formed of a material having a small friction coefficient so that the endless belt 62 can smoothly rotate, and further has a low thermal conductivity so that it is difficult to remove heat from the endless belt 62. It is made of material.
Further, the flange portion 802 is disposed such that inner surfaces of both flange portions 802 disposed so as to face each other at both end portions of the holder 65 have an interval substantially matching the width of the endless belt 62. When the endless belt 62 rotates, the end of the endless belt 62 abuts against the inner surface of the flange portion 802, so that the movement of the endless belt 62 in the width direction (belt walk) is limited. . As described above, the endless belt 62 is supported by the edge guide member 80 so that the deviation is regulated.

Further, the endless belt 62 is supported by the pressure pad 64 and the belt guide member 63 in the longitudinal region excluding both ends of the endless belt 62 (see also FIG. 1). In the region excluding both ends of the endless belt 62, the inner peripheral surface of the endless belt 62 rotates while sliding on the pressure pad 64 and the belt guide member 63.
The belt guide member 63 is attached to a holder 65 disposed inside the endless belt 62 along the longitudinal direction. The belt guide member 63 is formed with a plurality of ribs in the rotational direction of the endless belt 62 so as to minimize the contact area with the inner peripheral surface of the endless belt 62. Further, the belt guide member 63 is made of a material having a low coefficient of friction so that the endless belt 62 can smoothly rotate, and a material having a low thermal conductivity so that it is difficult to remove heat from the endless belt 62. Is formed. Specifically, a heat resistant resin such as tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA) or polyphenylene sulfide (PPS) is used.

  Next, the pressure pad 64 is supported by a metal holder 65 inside the endless belt 62. Then, it is arranged in a state of being pressed against the fixing roll 61 via the endless belt 62, and forms a nip portion N with the fixing roll 61. In the pressure pad 64, a pre-nip member 64 a for securing a wide nip portion N is disposed on the inlet side (upstream side) of the nip portion N. Further, on the outlet side (downstream side) of the nip portion N, the surface of the fixing roll 61 is locally pressed to smooth the surface of the toner image and impart image gloss, and the surface of the fixing roll 61 is distorted (dented). ), And a peeling nip member 64b for forming a down curl on the paper P is disposed.

Further, the pressure pad 64 is provided with a low friction sheet 68 as an example of a low friction member on the surface in contact with the endless belt 62 in order to reduce the sliding resistance between the inner peripheral surface of the endless belt 62 and the pressure pad 64. It has been.
The low friction sheet 68 is fixed to the holder 65 at the upstream end of the nip portion N by a low friction sheet fixing member 68a. And it is arrange | positioned over the whole region of the nip part N in the state clamped between the pressure pad 64 and the inner peripheral surface of the endless belt 62 along the rotation direction of the endless belt 62. The downstream side of the nip portion N of the low friction sheet 68 is not fixed and set to a free end (free) state so that the low friction sheet 68 is not distorted. The low friction sheet 68 has a sliding resistance between the inner peripheral surface of the endless belt 62 and the pressure pad 64 under a state in which a pressing force is applied between the pressure pad 64 and the fixing roll 61 at the nip portion N. (Friction resistance) is reduced.

  In such a configuration, the fixing roll 61 is connected to a drive motor (not shown) and rotates in the direction of arrow A, and the endless belt 62 rotates in the same direction as the fixing roll 61 following this rotation. The sheet P on which the toner image is electrostatically transferred is guided by the fixing entrance guide 56 and conveyed to the nip portion N. When the paper P passes through the nip portion N, the toner image on the paper P is fixed by the pressure acting on the nip portion N and the heat supplied from the fixing roll 61. In the fixing device 1 of the present embodiment, since the nip portion N can be widely configured by the concave pre-nip member 64a that substantially follows the outer peripheral surface of the fixing roll 61, stable fixing performance can be ensured.

  In the vicinity of the downstream side of the nip portion N, the paper P peeled off from the fixing roll 61 by the peeling nip member 64b is completely separated from the fixing roll 61 and guided to the paper discharge path toward the discharge portion of the image forming apparatus. A peeling assisting member 70 is provided for this purpose. The peeling auxiliary member 70 is held by a baffle holder 72 in a state in which the peeling baffle 71 is close to the fixing roll 61 in a direction (counter direction) opposite to the rotation direction of the fixing roll 61.

  Next, each member constituting the fixing device 1 will be described in detail. First, the endless belt 62 is a seamless endless belt whose original shape is formed in a cylindrical shape so that a defect due to the seam does not occur in the output image. The base layer and the surface of the base layer on the fixing roll 61 side (Peripheral surface) or a release layer (surface layer) coated on both surfaces. For the base layer, a polymer such as a thermosetting polyimide resin, a thermoplastic polyimide resin, a polyamideimide resin, or a polybenzimidazole resin is preferably used from the viewpoint of heat resistance, mechanical properties, and the like. The thickness is set to about 30 to 200 μm, preferably 50 to 125 μm, more preferably about 75 to 100 μm.

As the release layer (surface layer) coated on the surface of the base layer, a fluororesin is used. Here, as the fluororesin, polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-per Fluoromethyl vinyl ether copolymer (MFA), tetrafluoroethylene-perfluoroethyl vinyl ether copolymer (EFA), polyethylene-tetrafluoroethylene (ETFE), polyvinylidene fluoride (PVDF), polychlorotrifluoride ethylene (PCTFE), Examples thereof include vinyl fluoride (PVF). In particular, from the viewpoints of heat resistance, mechanical properties, etc., polytetrafluoroethylene (PTFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene-perfluoromethyl vinyl ether copolymer (MFA), tetra A fluoroethylene-perfluoroethyl vinyl ether copolymer (EFA) and a tetrafluoroethylene-hexafluoropropylene copolymer (FEP) are preferably used. The thickness is set to about 5 to 100 μm, preferably about 10 to 30 μm.
In the fixing device 1 of the present embodiment, an endless belt 62 having a configuration in which a release layer made of PFA having a thickness of 30 μm is laminated on a base layer made of thermosetting polyimide having a peripheral length of 94 mm, a thickness of 75 μm, and a width of 320 mm. Used.

As described above, the pressure pad 64 disposed inside the endless belt 62 includes the pre-nip member 64a and the peeling nip member 64b, and presses the fixing roll 61 with a load of, for example, 35 kgf by a spring or an elastic body. Is supported by the holder 65. An elastic body such as silicone rubber or fluororubber, a leaf spring, or the like can be used for the prenip member 64 a, and the surface on the fixing roll 61 side is formed with a concave curved surface that substantially follows the outer peripheral surface of the fixing roll 61. In the fixing device 1 of the present embodiment, silicone rubber having a width of 10 mm, a thickness of 5 mm, and a length of 320 mm is used.
The peeling nip member 64b is formed of a heat-resistant resin such as PPS, polyimide, polyester, or polyamide, or a metal such as iron, aluminum, or SUS. As the shape of the peeling nip member 64b, the outer surface shape in the nip portion N is formed as a convex curved surface having a constant radius of curvature.
In the fixing device 1 of the present embodiment, the endless belt 62 is wrapped around the fixing roll 61 by the pressure pad 64 at an angle of about 40 ° to form a nip portion N having a width of about 10 mm.

  Further, the holder 65 is provided with a lubricant application member 67 along the longitudinal direction of the fixing device 1. The lubricant application member 67 is disposed so as to contact the inner peripheral surface of the endless belt 62 and supplies an appropriate amount of lubricant. As a result, the lubricant is supplied to the sliding portion between the endless belt 62 and the low friction sheet 68, and the sliding resistance between the endless belt 62 and the pressure pad 64 via the low friction sheet 68 is further reduced. 62 is smoothly rotated. Further, it has an effect of suppressing wear on the inner peripheral surface of the endless belt 62 and the surface of the low friction sheet 68.

  As the lubricant, a lubricant that has durability against long-term use under a fixing temperature environment and can maintain wettability with the inner peripheral surface of the endless belt 62 is suitable. For example, liquid oil such as silicone oil or fluorine oil, synthetic lubricating oil grease in which a solid substance and a liquid are mixed, or a combination thereof can be used. Silicone oils include dimethyl silicone oil, dimethyl silicone oil with organometallic salt addition, dimethyl silicone oil with hindered amine addition, dimethyl silicone oil with organometallic salt and hindered amine addition, methylphenyl silicone oil, amino-modified silicone oil, amino-modified silicone-added amino-modified silicone. Oil, hindered amine-added amino-modified silicone oil, carboxy-modified silicone oil, silanol-modified silicone oil, sulfonic acid-modified silicone oil, and the like can also be used. Moreover, as fluoro oil, perfluoropolyether oil and modified perfluoropolyether oil can be used. In the fixing device 1 of the present embodiment, amino-modified silicone oil is used.

Next, the fixing roll 61 will be described.
As shown in FIG. 3, the fixing roll 61 of the present embodiment is configured by laminating a heat-resistant elastic body layer 612 and a release layer 613 around a metal core (cylindrical cored bar) 611. Has been. The core 611 is formed of a cylindrical body having an outer diameter of 30 mm, a wall thickness of 1.8 mm, and a length of 360 mm, which is formed of a metal having high thermal conductivity such as iron, aluminum (for example, A-5052), or SUS. Has been.
The heat-resistant elastic body layer 612 is made of an elastic body having high heat resistance, and in particular, an elastic body such as silicone rubber, fluororubber, or elastomer having a rubber hardness of about 15 to 45 ° (JIS-A) is used. As described above, the heat-resistant elastic body layer 612 is provided in the fixing roll 61 because the toner image on the paper P to be fixed is formed by laminating toner powder. This is because, in order to supply heat uniformly to the entire toner image at N, it is preferable that the fixing belt 62 can be deformed so as to follow the unevenness of the toner image on the paper P. In particular, when fixing a color toner image in which toners of each color of yellow, magenta, cyan, and black are laminated, the heat resistant elastic layer 612 is important from the viewpoint of color development.

  The heat resistant elastic layer 612 is formed as a thin layer having a thickness of 1 mm or less. Here, the reason why the heat-resistant elastic layer 612 is formed as a thin layer having a thickness of 1 mm or less is based on the following reason. That is, the heat-resistant elastic body layer 612 made of rubber, elastomer, or the like has a low thermal conductivity, and thus acts as a resistor against heat conduction. For this reason, even if a sufficient amount of heat is supplied from the halogen heater 66 inside the fixing roll 61, a phenomenon occurs in which the heat is not quickly transmitted to the surface of the fixing roll 61. Therefore, in the fixing roll 61 of this embodiment, the heat-resistant elastic body layer 612 is thinned. By forming the heat-resistant elastic body layer 612 as a thin layer, the resistance to heat conduction can be reduced, so that the time required for the fixing roll 61 to rise from room temperature to a fixable temperature (warm-up time) is shortened and reduced. It becomes possible to realize power consumption (energy saving).

  Further, the heat-resistant elastic body layer 612 is formed such that the fixing roll 61 is formed in a so-called “flare shape” in the axial direction by being relatively thin at the center and relatively thick at both ends. ing. Thus, by forming the fixing roll 61 in a flare shape, the surface speed of the fixing roll 61 becomes faster at both ends, so the moving speed of the paper P passing through the nip portion N becomes relatively higher at both ends. . As a result, a force in the width direction acts on the paper P from the center to both ends. And it becomes possible to suppress that a paper wrinkle arises in the paper P because the force which goes to this width direction pulls the paper P to both width directions.

  From the above viewpoint, in the fixing roll 61 of the present embodiment, the heat-resistant elastic body layer 612 is made of silicone rubber, and the heat-resistant elastic body layer 612 has a thickness of 600 μm at the axial center and both ends. It is formed in a thin layer of 650 μm. Accordingly, the fixing roll 61 is formed in a so-called “flare shape” in which the outer diameter linearly increases from the center portion toward both ends.

For the release layer 613, for example, a heat-resistant resin such as a silicone resin or a fluororesin is used, and a fluororesin is suitable from the viewpoint of the releasability to the toner and the wear resistance. As the fluororesin, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP) and the like can be used.
With respect to the thickness of the release layer 613, since the heat-resistant elastic layer 612 is formed as a thin layer having a thickness of 1 mm or less, the release layer is formed so as not to reduce the elasticity of the heat-resistant elastic layer 612. It is necessary to form 613 thinly, and 5 to 100 μm, particularly 10 to 30 μm is preferable.

Furthermore, in the fixing roll 61 of the present embodiment, as described above, the fixing roll 61 is formed in a flare shape having different outer diameters in the axial direction, and the heat-resistant elastic body layer 612 has a thin layer thickness of 1 mm or less. At the same time as being formed, the surface of the release layer 613 is a smooth surface having no scratches (recesses) deeper than a predetermined value, specifically, the arithmetic average roughness Ra is 0.02 μm or less, and the maximum The height Rmax is formed with a smooth surface having no concave portion larger than 4.0 μm (that is, Rmax ≦ 4.0 μm).
The maximum height Rmax here refers to the height from the lowest valley bottom to the highest mountain peak according to the JIS-82 standard. Further, Rmax and Ra are measured using a surfcom surface roughness measuring machine (manufactured by Toyo Seiki Co., Ltd.), and the roughness measuring mode is: measurement length: 2.5 mm, cutoff wavelength: 0.25 mm, cutoff type : 2CR (phase non-compensation), tilt correction: least square line correction, measurement speed: 0.06 mm / sec.

  By the way, conventionally, in the manufacturing method of the fixing roll 61, the core 611 is coaxially installed in the cylindrical mold, and an addition reaction type silicone rubber or the like is provided in the gap between the cylindrical mold and the core 611. A method of injecting heat-resistant rubber, curing it, and removing the mold is employed. In such a manufacturing method, when the heat-resistant elastic layer 612 is formed thick, the amount of heat shrinkage of the heat-resistant elastic layer 612 after cooling is large. A sufficient space can be secured between the inner surface of the mold and the release layer 613 coated on the surface of the heat resistant elastic layer 612. Therefore, even when formed in a flare shape in which the outer diameters at both ends are larger than those at the central portion, the inner surface of the cylindrical mold and the release layer 613 coated on the surface of the heat-resistant elastic body layer 612 at the time of demolding. Almost no friction between the surfaces of both ends occurred.

  However, when the heat-resistant elastic body layer 612 is formed as a thin layer having a thickness of 1 mm or less, the heat-resistant elastic body layer 612 after cooling has a small amount of heat shrinkage. A sufficient gap cannot be secured between the inner surface and the heat resistant elastic layer 612. Therefore, in the flare shape in which the outer diameters at both ends are larger than those at the center, the inner surface of the cylindrical mold and the release layers 613 at both ends rub against each other at the time of demolding, and the release layer 613. Occurrence of pull-out scratches on the surfaces of both ends was inevitable. Such a phenomenon occurs uniformly in a roll formed with different outer diameters in the axial direction, is relatively large at the central portion in the axial direction, and is relatively small at both ends, so-called “crown-shaped” fixing. The same applies to the roll 61 (in this case, a pull-out scratch occurs at the central portion having a large outer diameter). When such a scratch is generated on the surface of the fixing roll 61, the toner carried on the paper P is offset and fixed to the surface, and this may cause the quality of the fixed image to deteriorate. .

On the other hand, in the fixing roll 61 of the present embodiment, the manufacturing method described below is used to form a flare shape with different outer diameters in the axial direction, and the heat-resistant elastic layer 612 has a thickness of 1 mm or less. At the same time, the surface of the release layer 613 is a smooth surface having no scratches (concave portions) whose depth is greater than a predetermined value, specifically, the arithmetic average roughness Ra is 0.02 μm or less. In addition, it is characterized in that it is formed with a smooth surface without a recess having a maximum height Rmax larger than 4.0 μm (that is, Rmax ≦ 4.0 μm). In the conventional manufacturing method, due to the reasons described above, the fixing roller 61 is a thin layer having a heat-resistant elastic body layer 612 having a thickness of 1 mm or less and having a flare shape. It was difficult to form a smooth surface satisfying 0.0 μm or less.
With such a fixing roll 61 of the present embodiment, it is possible to reduce the warm-up time and reduce the power consumption, and to form a high-quality fixed image that satisfies a predetermined standard.

Below, the manufacturing method of the fixing roll 61 of this Embodiment is demonstrated. Here, FIG. 4 is a diagram showing a schematic configuration of a manufacturing apparatus for the fixing roll 61, which will be described with reference to FIG.
(1) First, as shown in FIG. 4, a sleeve (resin sleeve) formed of a resin having an outer diameter slightly smaller than the inner diameter of the cylindrical mold 101 along the inner peripheral surface of the cylindrical mold 101. 102 is placed inside. The resin sleeve 102 is formed of a resin having a large linear expansion coefficient, such as a fluororesin. In this case, the resin sleeve 102 may be configured integrally with the cylindrical mold 101 or may be configured separately and inserted.
Further, the inner diameter of the cylindrical mold 101 is formed so as to be relatively small at the central portion and linearly increase toward both end portions. Therefore, in the state where the resin sleeve 102 is fitted in the inner peripheral surface of the cylindrical mold 101, the inner diameter of the resin sleeve 102 is similarly relatively small at the center portion and linearly increases toward both ends. It is set as follows.

(2) Next, a fluororesin tube (fluororesin tube) 103 having an outer diameter slightly smaller than the inner diameter of the resin sleeve 102 is attached along the inner peripheral surface of the resin sleeve 102. The outer diameter of the fluororesin tube 103 is preferably formed between the inner diameter of the resin sleeve 102 and about 90% of the inner diameter of the resin sleeve 102. When the outer diameter of the fluororesin tube 103 is larger than the inner diameter of the resin sleeve 102, wrinkles are caused. On the other hand, when the outer diameter is too smaller than the inner diameter of the resin sleeve 102, This is because it tears when attached to the surface, or the layer thickness of the silicone rubber after molding described later becomes non-uniform.
Moreover, in order to improve adhesiveness with the silicone rubber mentioned later, the adhesion | attachment pre-processes, such as an etching process and a plasma processing process, are given to the internal peripheral surface of the fluororesin tube 103. FIG.

(3) Then, a cylindrical cored bar 104 is inserted into the attached fluororesin tube 103 and is installed coaxially with the cylindrical mold 101 and the resin sleeve 102. The surface of the cylindrical cored bar 104 can be blasted or coated with an adhesive in order to improve adhesion to the silicone rubber described later.
(4) Subsequently, the air between the resin sleeve 102 and the fluororesin tube 103 is sucked and extracted, and the pressure between the resin sleeve 102 and the fluororesin tube 103 is set to an appropriate pressure between atmospheric pressure and 0.1 Torr. Set.
When the air between the resin sleeve 102 and the fluororesin tube 103 is sucked, an air vent hole 105 is provided on the side surface in the axial direction of the cylindrical mold 101 and the resin sleeve 102, and the pipe 106 is connected through the air vent hole 105. Air is sucked through. Although one air vent hole 105 may be provided, it is desirable to provide two or more air vent holes. This is because the fluororesin tube 103 is firmly fixed to the inner peripheral surface of the resin sleeve 102.

(5) After sucking the air between the resin sleeve 102 and the fluororesin tube 103, after a predetermined time of 0 to 10 seconds, from one end of the fluororesin tube 103, the cylindrical metal core 104 and the fluororesin Appropriate pressure (between atmospheric pressure and 0.1 Torr) equal to or greater than the pressure between the resin sleeve 102 and the fluororesin tube 103 is sucked and extracted from the air in the gap 107 between the tube 103 and the tube 103. Pressure).
(6) After sucking the air in the gap between the cylindrical cored bar 104 and the fluororesin tube 103, the fluorine on the side opposite to the end where the air is sucked after a predetermined time between 0 and 10 seconds. Appropriate pressure between 0.1 to 5 MPa, which is a material pressure, is applied to the addition reaction type silicone rubber in the gap 107 between the cylindrical cored bar 104 and the fluororesin tube 103 from the other end of the resin tube 103. Injected by.
The reason why the addition-reaction type silicone rubber is used is that it is vulcanized inside the resin sleeve 102, and therefore it is preferable that it does not generate gas. In addition, if the viscosity of the silicone rubber is too high, it may not be injected into the gap between the cylindrical cored bar 104 and the fluororesin tube 103, so it is preferably 1000 Pa · s or less.

(7) The silicone rubber injected into the gap 107 between the cylindrical metal core 104 and the fluororesin tube 103 is heated to a vulcanization temperature (100 to 140 ° C.) and vulcanized to cure the silicone rubber. . As a result, the cylindrical cored bar 104 and the fluororesin tube 103 are integrally bonded via the silicone rubber.
(8) Then, it is cooled. Thus, a roll in which the cylindrical cored bar 104, the silicone rubber, and the fluororesin tube 103 are integrated is molded. At that time, as described above, the inner diameter of the resin sleeve 102 is set to be relatively small at the center and linearly increases toward both ends (see (1)). The outer diameter is small at the center and is linearly increased toward both ends. Therefore, the roll is formed in a so-called “flare” shape.
(9) The molded roll is removed from the cylindrical mold 101 and the resin sleeve 102. The cylindrical metal core 104 constitutes the core 611 of the fixing roll 61, the cured silicone rubber constitutes the heat-resistant elastic body layer 612, and the fluororesin tube 103 constitutes the release layer 613.

  As described above, in the method of manufacturing the fixing roll 61 according to the present embodiment, the fixing roll 61 is formed of a resin having an outer diameter slightly smaller than the inner diameter of the cylindrical mold 101 along the inner peripheral surface of the cylindrical mold 101. It is characterized in that the resin sleeve 102 is fitted inside. When the resin sleeve 102 is fitted inside the cylindrical mold 101, the silicone rubber injected into the gap 107 between the cylindrical core metal 104 and the fluororesin tube 103 is heated to the vulcanization temperature. (Described above (7)), the resin sleeve 102 is thermally expanded. Then, the resin sleeve 102 expands to the inner peripheral surface side (cylindrical cored bar 104 side) to define a gap 107 between the cylindrical cored bar 104 and the fluororesin tube 103, and thereby the silicone rubber layer thickness. Is set. That is, the gap 107 between the cylindrical cored bar 104 and the fluororesin tube 103 is set in advance assuming the thermal expansion of the resin sleeve 102 at the vulcanization temperature. The layer thickness of the silicone rubber is set by the gap 107 between the cylindrical cored bar 104 and the fluororesin tube 103 in the vulcanization temperature state.

When this is cooled (described above (8)), the resin sleeve 102 contracts to the original inner diameter. On the other hand, the silicone rubber layer thickness is cured in a state determined by the gap 107 between the cylindrical cored bar 104 and the fluororesin tube 103 in the vulcanization temperature state. Therefore, after cooling, a sufficient gap is generated between the fluororesin tube 103 bonded to the silicone rubber and the resin sleeve 102.
Since a sufficient gap is generated between the fluororesin tube 103 and the resin sleeve 102, the roll is formed in a flare shape, but the portion with the largest outer diameter of the roll, that is, both end regions of the roll are The resin sleeve 102 can pass through the central portion, which is the region having the smallest inner diameter, without rubbing. Therefore, the surface of the roll (the surface of the fluororesin tube 103) does not rub against the resin sleeve 102 even when the roll is removed in (9) described above. Therefore, at the time of demolding, on the surface of the roll (the surface of the fluororesin tube 103), it is possible to form a smooth surface without a pulling scratch such that the maximum height Rmax is larger than 4.0 μm.

  As described above, in the method of manufacturing the fixing roll 61 according to the present embodiment, the resin sleeve 102 is fitted into the inner peripheral surface of the cylindrical mold 101, thereby causing sufficient heat shrinkage in the resin sleeve 102 during cooling. Can be made. Therefore, even when the heat-resistant elastic body layer 612 of the fixing roll 61 is thinned, the inner surface of the resin sleeve 102 and the both ends of the fixing roll 61 are interposed between the fixing roll 61 and the resin sleeve 102 after cooling. Sufficient voids that do not rub against the release layer 613 can be generated. This makes it possible to suppress the surface of the fixing roll 61 from being pulled out of the cylindrical mold 101.

Therefore, the resin sleeve 102 is formed so that a sufficient amount of heat shrinkage can be obtained during cooling. That is, when the flare amount of the outer diameter of the fixing roll 61 (radius difference between the end portion in the axial direction and the central portion) is, for example, 50 μm, the resin sleeve 102 is cooled by the cooling from the vulcanization temperature to the normal temperature. It is necessary to configure so as to contract by 100 μm or more in terms of conversion. Therefore, it is preferable to use a material having a large linear expansion coefficient as the resin sleeve 102. In particular, the linear expansion coefficient is preferably 5 × 10 ⁻⁵ (/ ° C.) or more. With a linear expansion coefficient of 5 × 10 ⁻⁵ (/ ° C.) or more, the fixing roll 61 generally has an outer diameter of 30 mm, a vulcanization temperature of about 100 to 140 ° C., and the flare amount of the fixing roll 61 is about 50 μm. This is because the amount of shrinkage can be set to be 100 μm or more in terms of inner diameter.
Further, the material used for the resin sleeve 102 is preferably a fluororesin. This is because the fluororesin has good slipperiness and is hardly scratched even by rubbing, and has a large linear expansion coefficient of 10 to 12 × 10 ⁻⁵ (/ ° C.).
Even if the material has a linear expansion coefficient smaller than 5 × 10 ⁻⁵ (/ ° C.), the amount of thermal shrinkage can be sufficiently increased by forming the resin sleeve 102 thick.

Hereinafter, based on an Example and the comparative example with respect to this, the manufacturing method of the fixing roll 61 of this Embodiment is demonstrated concretely. Note that the manufacturing method of the fixing roll 61 of the present embodiment is not limited to the examples.
Example 1
A resin sleeve having an outer diameter of 35.5 mm and an inner diameter of 31.5 mm (wall thickness: 2 mm) is obtained by an extrusion method using PFA (manufactured by Mitsui DuPont Fluorochemical Co., Ltd .: Teflon (registered trademark) HP-450-J). It was. This resin sleeve was fitted in an iron (S45C) mold having an inner diameter of 35.55 mm. Next, fluorine having an outer diameter of 30.17 mm and a thickness of 30 μm formed of PFA (manufactured by Mitsui DuPont Fluorochemical Co., Ltd .: Teflon (registered trademark) HP-450-J) and subjected to adhesion treatment on the inner peripheral surface A resin tube was attached to the inner peripheral surface of the resin sleeve. Then, the pressure between the fluororesin tube and the resin sleeve was reduced to expand the fluororesin tube to the inner peripheral surface of the resin sleeve.

An aluminum (A-5052) core material having an outer diameter of φ29.84 mm whose surface was subjected to an adhesive treatment was inserted into the resin sleeve and installed coaxially. Then, an addition reaction type liquid silicone rubber having a viscosity of 200 Pa · s was injected into the gap between the aluminum core and the fluororesin tube at a pressure of 4 MPa. Thereafter, a vulcanization reaction was performed at 120 ° C. for 1 hour.
After cooling this, the fixing roll made of silicone rubber and fluororesin tube integrated with the aluminum core was removed from the resin sleeve.
As a result, the thickness of the elastic layer of the fixing roll could be formed as a thin layer of 600 μm. At that time, it was easy to remove the fixing roll, and it was possible to form a smooth surface without any pull-out scratches on the surface of the fixing roll.

(Example 2)
A resin sleeve having an outer diameter of 35.5 mm and an inner diameter of 31.5 mm (wall thickness: 2 mm) is obtained by an extrusion method using PFA (manufactured by Mitsui DuPont Fluorochemical Co., Ltd .: Teflon (registered trademark) HP-450-J). It was. This resin sleeve was fitted into an iron (S45C) mold. This iron metal mold has an inner diameter of 35.55 mm at the center and an inner diameter of 35.65 mm at both ends, and the inner diameter increases linearly from the center toward both ends. Next, fluorine having an outer diameter of 30.17 mm and a thickness of 30 μm formed of PFA (manufactured by Mitsui DuPont Fluorochemical Co., Ltd .: Teflon (registered trademark) HP-450-J) and subjected to adhesion treatment on the inner peripheral surface A resin tube was attached to the inner peripheral surface of the resin sleeve. Then, the pressure between the fluororesin tube and the resin sleeve was reduced to expand the fluororesin tube to the inner peripheral surface of the resin sleeve.

An aluminum (A-5052) core material having an outer diameter of φ29.84 mm whose surface was subjected to an adhesive treatment was inserted into the resin sleeve and installed coaxially. Then, an addition reaction type liquid silicone rubber having a viscosity of 200 Pa · s was injected into the gap between the aluminum core and the fluororesin tube at a pressure of 4 MPa. Thereafter, a vulcanization reaction was performed at 120 ° C. for 1 hour.
After cooling this, the fixing roll made of silicone rubber and fluororesin tube integrated with the aluminum core was removed from the resin sleeve.
As a result, the thickness of the elastic layer of the fixing roll is a thin layer of 650 μm at both ends and 600 μm at the center, and can be formed in a flare shape that increases linearly from the center to both ends. did it. At that time, demolding of the fixing roll was easy to the extent that there was some resistance but there was no problem, and it was possible to form a smooth surface without any pull-out scratches on the surface of the fixing roll.

(Comparative Example 1)
It is made of an iron (S45C) mold with an inner diameter of 31.15 mm, made of PFA (Mitsui DuPont Fluorochemical Co., Ltd .: Teflon (registered trademark) HP-450-J), and the outer peripheral surface is bonded. A fluororesin tube having a diameter of 31.1 mm and a wall thickness of 30 μm was attached to the inner peripheral surface of the iron material mold. Then, the pressure between the fluororesin tube and the iron mold was reduced, and the fluororesin tube was extended to the inner peripheral surface of the iron mold.

An aluminum (A-5052) core material having an outer diameter of φ29.84 mm, the surface of which was subjected to adhesion treatment, was inserted into an iron material mold and installed coaxially. Then, an addition reaction type liquid silicone rubber having a viscosity of 200 Pa · s was injected into the gap between the aluminum core and the fluororesin tube at a pressure of 4 MPa. At that time, the injection took time, and the pressure had to be raised to 8 MPa. Thereafter, a vulcanization reaction was performed at 120 ° C. for 1 hour.
After cooling this, the fixing roll made of silicone rubber and fluororesin tube integrated with the aluminum core was removed from the resin sleeve.
As a result, although the thickness of the elastic layer of the fixing roll was able to be formed as a thin layer of 600 μm, the demolding of the fixing roll has a large resistance, and the surface of the fixing roll has numerous scratches in the drawing direction. It was.

(Comparative Example 2)
An outer diameter φ30.17 mm, which is formed of PFA (Mitsui DuPont Fluorochemical Co., Ltd .: Teflon (registered trademark) HP-450-J) on an iron material (S45C) mold, and an inner peripheral surface is subjected to an adhesion treatment. A fluororesin tube having a thickness of 30 μm was attached to the inner peripheral surface of the iron material mold. Then, the pressure between the fluororesin tube and the iron mold was reduced, and the fluororesin tube was extended to the inner peripheral surface of the iron mold. Here, the iron mold has an inner diameter of 31.15 mm at the center and an inner diameter of 31.25 mm at both ends, and the inner diameter increases linearly from the center toward both ends. .

An aluminum core material (A-5052) having an outer diameter of φ29.84 mm whose surface was subjected to an adhesion treatment was inserted into an iron material mold and installed coaxially. Then, an addition reaction type liquid silicone rubber having a viscosity of 200 Pa · s was injected into the gap between the aluminum core and the fluororesin tube at a pressure of 4 MPa. At that time, the injection took time, and the pressure had to be raised to 8 MPa. Thereafter, a vulcanization reaction was performed at 120 ° C. for 1 hour.
After cooling this, the fixing roll made of silicone rubber and fluororesin tube integrated with the aluminum core was removed from the resin sleeve.
As a result, the thickness of the elastic layer of the fixing roll was 700 μm at both ends and 650 μm at the center, and the flare shape was linearly increased from the center toward both ends. The fixing roll was demolded with high resistance and could not be demolded at all.

Next, the necessity of forming the surface of the fixing roll 61 to 4.0 μm or less with respect to the maximum height Rmax will be described.
As described above, when the surface of the fixing roll 61 is scratched, the toner carried on the paper P is offset and fixed thereto, which causes the quality of the fixed image to deteriorate. Specifically, the toner on the paper P is further adsorbed to the toner that is offset and fixed to the scratched portion on the surface of the fixing roll 61, and this toner is transferred again onto the paper P during the fixing operation, so that the fixed image is obtained. The phenomenon of getting dirty.
Therefore, the degree of contamination of the fixed image was evaluated using the fixing roll 61 having different depths of scratches on the surface of the fixing roll 61, that is, the maximum height Rmax. FIG. 5 is a diagram comparing the maximum height Rmax and the stain on the fixed image. As shown in FIG. 5, when the maximum height Rmax is 4.0 μm or less, the fixed image is not noticeably stained, and a high-quality fixed image can be obtained. On the other hand, when Rmax exceeds 4.0 μm, the fixed image starts to show stains following the shape of the scratched portion, and when Rmax exceeds 5.0 μm, the fixed image cannot be overlooked. .
From such a result, it is necessary to form the surface of the fixing roll 61 with Rmax ≦ 4.0 μm with respect to the maximum height Rmax, and this can be realized by using the manufacturing method of the present embodiment described above. It becomes.

  In addition, as the surface roughness of the smooth portion other than the concave portion on the surface of the fixing roll 61, the arithmetic average roughness is formed such that Ra ≦ 0.02 μm. That is, the surface of the fixing roll 61 is formed so that Ra ≦ 0.02 μm, which is the arithmetic average roughness of the original surface of the fluororesin tube 103 constituting the release layer 613. And by the manufacturing method of the present embodiment, a scratch (concave portion) having a maximum height Rmax larger than 4.0 μm is not formed on the smooth surface having the arithmetic average roughness Ra ≦ 0.02 μm of the original surface. The fixing roll 61 can be formed.

  As described above, the fixing roll 61 formed by the manufacturing method of the present embodiment is formed in a flare shape having different outer diameters in the axial direction, and the heat-resistant elastic body layer 612 is a thin layer having a thickness of 1 mm or less. At the same time, the surface of the release layer 613 has an arithmetic average roughness Ra ≦ 0.02 μm and no recess having a maximum height Rmax larger than 4.0 μm (that is, Rmax ≦ 4. 0 μm) formed on a smooth surface. With such a fixing roll 61 of the present embodiment, it is possible to reduce the warm-up time and reduce the power consumption, and to form a high-quality fixed image that satisfies a predetermined standard.

  Here, in the manufacturing method of the fixing roll 61 according to the present embodiment, the fixing roll 61 is formed of a resin having an outer diameter slightly smaller than the inner diameter of the cylindrical mold 101 along the inner peripheral surface of the cylindrical mold 101. The resin sleeve 102 is fitted inside. Thus, when the mold is removed, the resin sleeve 102 sufficiently heat shrinks. Therefore, even when the heat resistant elastic body layer 612 of the fixing roll 61 is formed in a thin flare shape, the fixing roll 61 and the resin An air gap can be generated between the sleeve 102 and the sleeve 102. Therefore, the surface of the fixing roll 61 is prevented from being rubbed against the cylindrical mold 101 to cause pull-out scratches, and the surface of the fixing roll 61 has an arithmetic average roughness Ra ≦ 0.02 μm and a maximum height. It is possible to form a smooth surface having no recess having a thickness Rmax greater than 4.0 μm (that is, Rmax ≦ 4.0 μm).

  As an application example of the present invention, application to an image forming apparatus such as a copying machine or a printer using an electrophotographic system, for example, application to a fixing apparatus that fixes an unfixed toner image carried on recording paper (paper). is there. Further, there is application to an image forming apparatus such as a copying machine or a printer using an ink jet method, for example, to a fixing device that dries an undried ink image carried on a recording paper (paper).

1 is a schematic configuration diagram illustrating a fixing device of the present invention. It is a figure explaining the structure by which an endless belt is supported. FIG. 4 is a cross-sectional view illustrating a configuration of a fixing roll. FIG. 2 is a diagram illustrating a schematic configuration of a fixing roll manufacturing apparatus. FIG. 6 is a diagram comparing a maximum height Rmax and a stain on a fixed image.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Fixing device, 61 ... Fixing roll, 611 ... Core, 612 ... Heat-resistant elastic body layer, 613 ... Release layer, 62 ... Endless belt, 63 ... Belt guide member, 64 ... Pressure pad, 64a ... Pre-nip member, 64b ... peeling nip member, 65 ... holder, 66 ... halogen heater, 67 ... lubricant application member, 68 ... low friction sheet, 69 ... temperature sensor, 70 ... peeling auxiliary member, 101 ... cylindrical mold, 102 ... resin sleeve, DESCRIPTION OF SYMBOLS 103 ... Fluororesin tube, 104 ... Cylindrical metal core, 105 ... Air vent hole, 106 ... Pipe, 107 ... Gap

Claims (13)

A step of placing a resin tube along the inner surface of the resin sleeve inside a cylindrical mold in which a cylindrical resin sleeve formed of resin is fitted;
Placing a cored bar coaxially with the mold and the resin sleeve inside the resin tube;
Injecting liquid rubber into the gap between the metal core and the resin tube;
A step of curing the liquid rubber, and molding a roll member in which the core metal and the resin tube are bonded via the cured rubber;
And a step of removing the roll member from the mold.   The method for manufacturing a fixing member according to claim 1, further comprising a step of depressurizing a gap between the resin sleeve and the resin tube so that the resin tube is in close contact with an inner surface of the resin sleeve.   The method for manufacturing a fixing member according to claim 1, wherein the resin sleeve has a linear expansion coefficient of 5 × 10 −5 (/ ° C.) or more.   The method for manufacturing a fixing member according to claim 1, wherein the resin sleeve is made of a fluororesin.   The method for manufacturing a fixing member according to claim 1, wherein an inner surface of the resin tube is pre-bonded.   2. The method of manufacturing a fixing member according to claim 1, wherein the liquid rubber is an addition reaction type silicone rubber. A fixing member molded using a cylindrical mold,
With a mandrel,
A heat-resistant elastic body layer having a thickness of 1 mm or less formed on the metal core;
A release layer coated on the surface of the heat-resistant elastic layer,
The release layer includes a smooth surface having an arithmetic average roughness Ra ≦ 0.02 μm or a smooth portion having an arithmetic average roughness Ra ≦ 0.02 μm and a concave portion having a maximum height Rmax ≦ 4.0 μm. A fixing member formed by a surface.   The fixing member according to claim 7, wherein the heat-resistant elastic layer has different thicknesses in the axial direction.   The fixing member according to claim 8, wherein the heat-resistant elastic layer has a relatively small thickness at the center in the axial direction and a relatively large thickness at both ends.   The fixing member according to claim 7, wherein the release layer has a thickness of 100 μm or less.   8. The release layer according to claim 7, wherein the release layer is formed of any one of polytetrafluoroethylene, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, and tetrafluoroethylene-hexafluoropropylene copolymer. Fixing member. A fixing device for fixing a toner image carried on a recording material,
A fixing member having a heat source;
A pressure member movable while contacting the fixing member,
The fixing member is
With a mandrel,
A heat-resistant elastic body formed on the cored bar and having a thickness of 1 mm or less, the thickness at the center in the axial direction being relatively thin, and the thickness at both ends being relatively thick. Layers,
The surface of the heat-resistant elastic layer is covered, and the surface is a smooth surface having an arithmetic average roughness Ra ≦ 0.02 μm, or a smooth portion having an arithmetic average roughness Ra ≦ 0.02 μm, and a maximum height Rmax ≦ 4. A fixing device comprising: a release layer formed on a surface including a 0 μm concave portion.   The pressure member is disposed inside the belt member that is movable while being in contact with the fixing member, and is pressed between the fixing member and the belt member by pressing the belt member against the fixing member. The fixing device according to claim 12, further comprising a pressure member that forms a nip portion through which the recording material passes.

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