JP2008299186A - Manufacturing method for elastic roller, fixing device, and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an elastic roller that contribute to the formation of a high quality image for a long period of time when being attached to, for example, a fixing device of an image forming apparatus, to provide a method for manufacturing the elastic roller, and to provide the fixing device and the image forming apparatus which can form a high quality image for a long period of time. <P>SOLUTION: The method for manufacturing the elastic roller 1 with a foam elastic layer 3 formed on the outer circumference surface of a shaft body 2, and a sleeve 4 formed on the outer circumference surface of the foam elastic layer 3 is characterized in that a roller stock body with the foam elastic layer 3 on the outer circumference surface of the shaft body 2 is placed under a pressure environment of 0.15 to 0.48 MPa to press-compress the foam elastic layer 3, the roller stock body is inserted into the sleeve 4, and the pressurizing state of the pressure environment is released. The fixing device and the image forming apparatus respectively includes the elastic roller 1 manufactured by the method. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method of manufacturing an elastic roller, a fixing device, and an image forming apparatus, and more particularly, contributes to stably forming a high-quality image when mounted on a fixing device of an image forming apparatus, for example. The present invention relates to an elastic roller manufacturing method, and a fixing device and an image forming apparatus capable of stably forming a high-quality image.

  Various image forming apparatuses using an electrophotographic system are employed in printers such as laser printers and video printers, copiers, facsimiles, and multi-function machines thereof. Various image forming apparatuses include a fixing device equipped with a fixing roller or the like that incorporates a heating unit such as a heating element in order to fix the developer image transferred to the recording medium. Since such a fixing device includes a fixing roller incorporating a heating unit therein, the preheating time is usually relatively long, the configuration thereof is complicated, and it is difficult to replace only the heating unit, etc. Problems may occur.

  As a fixing device that can solve at least one of these problems, a fixing device including an external heating unit that supplies heat to a fixing roller or the like from the outside can be cited. Examples of such external heating means include radiant heating means such as a halogen heater, direct heating means by contact, induction heating means by AC magnetic field formation, and the like. In the fixing device provided with these external heating means, the fixing roller is made of metal on the outer peripheral surface of the elastic layer, for example, as a heated part so that the fixing roller is efficiently heated by the heat from the external heating means. It has a coating.

  As such a roller, for example, Patent Document 1 describes a heating rotating body that includes an elastic layer inside and a metal sleeve having a thickness of 10 to 150 μm provided outside (Patent Document 1). (See Fig. 3 in Fig. 1). According to the column 0066 of Patent Document 1, the rotating body for heating is “the outer diameter of the iron core 11 is 9 mm, the thickness of the sponge elastic layer 12 formed by foaming silicon rubber is 8 mm, The metal sleeve 13 is manufactured by covering a SUS sleeve having a thickness of 5 to 200 μm ”.

  Further, claim 1 of Patent Document 2 states that “the metal core 16, the sponge layer 22 disposed on the outer periphery of the metal core 16 via the primer 20, and the sponge layer 22. The metal thin sleeve 26 bonded to the outer periphery via the adhesive layer 24 and the release layer 28 disposed on the outer periphery of the metal thin sleeve 26 so as to cover the metal thin sleeve 26 are configured. As one of the methods for manufacturing the fixing roller, “a sponge body comprising a metal core and a sponge layer having at least closed cells disposed so as to surround the outer periphery of the metal core is used as an inner diameter dimension of a metal thin sleeve. A first step of processing to have the above outer diameter, a second step of applying an adhesive to at least one of the outer peripheral surface of the sponge body and the inner peripheral surface of the thin metal sleeve, and the sponge Body and metal A third step of storing and pressurizing the meat sleeve in a pressurized container and making the outer diameter of the sponge body smaller than the inner diameter of the metal thin-walled sleeve; and in the pressurized container, A fourth step of forming the sleeve body by inserting the sponge body into the metal thin sleeve; and taking out the sleeve body from the pressurized container; the sponge body expands and the outer peripheral surface of the sponge body; And a sixth step of solidifying the adhesive to bond the sponge body and the metal thin sleeve to each other. Is a fixing roller manufacturing method characterized by the above.

  However, even if the fixing roller manufactured by the manufacturing method described in Patent Document 1 and Patent Document 2 is mounted on the fixing device of the image forming apparatus, a high-quality image may not be stably formed.

Japanese Patent Laid-Open No. 08-129313 JP 2004-53924 A

  An object of the present invention is to provide a method of manufacturing an elastic roller that contributes to stable formation of a high-quality image when mounted on, for example, a fixing device of an image forming apparatus. Another object of the present invention is to provide a fixing device and an image forming apparatus that can stably form a high-quality image.

As means for solving the problems,
Claim 1 is a method for manufacturing an elastic roller comprising a foamed elastic layer formed on an outer peripheral surface of a shaft body and a sleeve provided on the outer peripheral surface of the foamed elastic layer, wherein the outer peripheral surface of the shaft body A roller base provided with a foamed elastic layer is placed in a pressure environment of 0.15 to 0.48 MPa to compress and compress the foamed elastic layer, and the roller base is inserted into the sleeve. It is a method for producing an elastic roller characterized by releasing the pressure state,
A second aspect of the present invention is the elastic roller manufacturing method according to the first aspect, wherein the roller base is placed under the pressure environment within 5 minutes.
According to a third aspect of the present invention, in the elastic roller manufacturing method according to the first or second aspect, the pressure state is released at a reduced pressure speed of 1 × 10 ^{3 to} 5 × 10 ⁴ Pa / sec. ,
Claim 4 is a fixing device including an elastic roller manufactured by the elastic roller manufacturing method according to any one of claims 1 to 3.
A fifth aspect of the present invention is an image forming apparatus including the elastic roller manufactured by the elastic roller manufacturing method according to any one of the first to third aspects.

  According to the elastic roller manufacturing method of the present invention, the roller base is placed in a pressure environment of 0.15 MPa to 0.48 MPa to compress and compress the foamed elastic layer, and the roller base is inserted into the sleeve. Since the pressurized state of the pressure environment is later released, the foam structure in the foam elastic layer is prevented from being damaged, cracked and destroyed, and the foam elastic layer formed on the outer peripheral surface of the shaft body and the foam elastic layer An elastic roller provided with a smooth sleeve provided on the outer peripheral surface can be easily manufactured. Therefore, according to the present invention, it is possible to provide a method for manufacturing an elastic roller that contributes to the stable formation of a high-quality image, for example, when mounted on a fixing device of an image forming apparatus. In addition, according to the present invention, it is possible to provide a fixing device and an image forming apparatus that are provided with the elastic roller according to the present invention and can stably form a high-quality image.

  The method for manufacturing an elastic roller according to the present invention (hereinafter sometimes referred to as the manufacturing method according to the present invention) includes placing the roller base in a pressure environment of 0.15 to 0.48 MPa and adding a foamed elastic layer. It is characterized by releasing the pressure state of the pressure environment after compressing and inserting the roller body into the sleeve. As described above, even if the compression and compression of the foamed elastic layer under a specific pressure environment and the release of the pressure environment are performed, the foamed structure in the foamed elastic layer is damaged, cracked, or destroyed. In the elastic roller manufactured by the manufacturing method according to the present invention, the sleeve provided on the outer peripheral surface of the foamed elastic layer becomes smooth and is mounted on, for example, the fixing device of the image forming apparatus. Sometimes it contributes to forming high quality images.

  An elastic roller 1 as an embodiment of an elastic roller manufactured by the manufacturing method according to the present invention includes, for example, a foamed elastic layer 3 formed on the outer peripheral surface of a shaft body 2 and foamed as shown in FIG. And a sleeve 4 provided via an adhesive layer 5 formed on the outer peripheral surface of the elastic layer 3.

  The shaft body 2 only needs to have good conductive properties, and is also referred to as a so-called “core metal”.

  The foamed elastic layer 3 is formed on the outer peripheral surface of the shaft body 2 by a rubber composition described later. The foamed elastic layer 3 is a foamed elastic layer having cells on its inner and / or outer surface (cells opened on the outer peripheral surface of the elastic layer 3 in FIG. 1 and cross section of the elastic layer 3 in FIG. 2). None of the open cells are shown.) When the foamed elastic layer 3 has cells, the hardness of the foamed elastic layer 3 is lowered and the function of the elastic roller 1 is improved, which can contribute to forming a high-quality image. Here, the cell having the foamed elastic layer 3 includes a hollow region generated by foaming or decomposition of a foaming agent contained in the rubber composition, and a hollow region derived from a hollow filler contained in the rubber composition. Say. The plurality of cells in the foamed elastic layer 3 are in a state where they do not contact or communicate with other cells (referred to as independent cell states), a state where they contact or communicate with other cells (communication cell state) Or the independent cell state and the communication cell state may coexist. The foamed elastic layer 3 has a cell size, a presence rate, and the like determined according to various rollers used in the image forming apparatus.

  For example, the average cell diameter of the cells in the foamed elastic layer 3 is preferably 60 to 800 μm, and particularly preferably 100 to 400 μm. When the average cell diameter of the cells is in the above range, the foamed structure in the foamed elastic layer 3 can be effectively prevented from being damaged, cracked and broken even in the pressure range. The cells in the foamed elastic layer 3 preferably have an average cell wall width of 0.01 to 0.5 mm, particularly preferably 0.05 to 0.4 mm. When the average width of the cell walls is in the above range, the foamed structure in the foamed elastic layer 3 can be effectively prevented from being damaged, cracked and broken even in the pressure range. Moreover, it is preferable that the foaming rate in the foaming elastic layer 3 is 150 to 480%, and it is especially preferable that it is 200 to 450%. When the expansion ratio is within the above range, even if the expansion ratio is within the above pressure range, it is possible to effectively prevent the foam structure in the foamed elastic layer 3 from being damaged, cracked and broken. In the cell, the average cell diameter, the average width of the cell wall, and the foaming rate are the blending amount of the foaming agent or the hollow filler contained in the rubber composition to be described later forming the foamed elastic layer 3, the size of the hollow filler, It can be adjusted depending on the curing conditions of the rubber composition.

The average cell diameter of the cell is determined by observing an area of about 2 mm ² with an electron microscope or the like on the surface of the foamed elastic layer 3 or a cut surface obtained by cutting an arbitrary surface. Can be obtained as an average length obtained by arithmetically averaging the measured maximum length. As for the average width of the cell wall in the cell, an area of about 2 mm ² is observed with an electron microscope or the like on the surface of the elastic layer 3 or the cut surface when the elastic layer 3 is cut at an arbitrary surface, like the average cell diameter. Then, the distance between the cells existing in the observation visual field, that is, the width of the wall between the cells can be measured, and the measured value can be obtained by arithmetic averaging. The foaming rate of the foamed elastic layer 3 can be calculated from the volume and mass of the foamed elastic layer 3 measured by a conventional method.

  The foamed elastic layer 3 preferably has an Asker C hardness of 20-60. When the Asker C hardness is within the above range, a desired contact state or pressure contact state with respect to the contacted body can be maintained, which contributes to forming a high-quality image. For example, when the elastic roller 1 is mounted on the image forming apparatus as a fixing roller, a desired pressure contact state is maintained with respect to the pressure roller, and the nip width formed by the pressure roller and the fixing roller is increased. Therefore, the developer image transferred to the recording medium can be fixed as desired, and as a result, it can contribute to forming a high-quality image. The Asker C hardness can be a value obtained by measuring a plurality of locations of the foamed elastic layer 3 in accordance with JIS K6253 and arithmetically averaging the measured values. The Asker C hardness of the foamed elastic layer 3 is, for example, selecting the type of rubber and / or additive contained in the rubber composition forming the foamed elastic layer 3 and / or changing the blending amount thereof. In addition, it can be adjusted according to the molding conditions of the foamed elastic layer 3 and the like.

  The thickness of the foamed elastic layer 3 is not particularly limited, but is usually preferably adjusted to 2 to 20 mm, and particularly preferably adjusted to 3 to 12 mm.

  The sleeve 4 is provided on the outer peripheral surface of the adhesive layer 5. The sleeve 4 is formed of a metal material having high thermal conductivity such as iron, stainless steel, nickel, etc., and may have a single layer structure or a laminated structure in which two or more layers are laminated. The sleeve 4 has a single layer structure or a laminated structure, and is usually formed in a thin layer. For example, the entire thickness is preferably 20 to 150 μm, and preferably 30 to 100 μm. Particularly preferred. It is preferable that the sleeve 4 has a tensile strength of about 800 to 1300 MPa because it is difficult to be deformed by the pressure contact from the inner peripheral surface of the foamed elastic layer 3. The measuring method of the tensile strength is based on JIS Z 2241.

  As shown in FIG. 2, the elastic roller 1 may have an adhesive layer 5 between the foamed elastic layer 3 and the sleeve 4. The adhesive forming the adhesive layer 5 is not particularly limited as long as it is an adhesive that can bond the foamed elastic layer 3 and the sleeve 4. For example, a silicone-based adhesive (trade name “KE-44” and “KE-45”, all manufactured by Shin-Etsu Chemical Co., Ltd.) and the like. In the present invention, the adhesive is fluid at room temperature (25 ° C.), specifically, a fluid adhesive having a viscosity at 25 ° C. of 15 to 150 Pa · s in the adhesive coating layer. It is preferable in that bubbles can be prevented from being generated and mixed, and the foamed elastic layer 3 and the sleeve 4 can be firmly bonded. As for the fluidity in the fluid adhesive, the viscosity at 25 ° C. is preferably 15 to 150 Pa · s, more preferably 30 to 120 Pa · s, and particularly preferably 50 to 100 Pa · s. When the viscosity of the fluid adhesive is within the above range, bubbles and the like are generated in the adhesive coating layer, and bubbles and the like can be effectively prevented from being mixed. The viscosity of the fluid adhesive is measured according to JIS K 6249 (using a BH viscometer).

  Examples of the fluid adhesive include a silicone adhesive and an acrylic adhesive. More specifically, as a silicone-based adhesive, addition type silicone RTV (for example, trade name “KE1880” (viscosity (25 ° C.) 84 Pa · s, manufactured by Shin-Etsu Chemical Co., Ltd.), trade name “KE1830” (viscosity ( 25 Pa), 110 Pa · s, manufactured by Shin-Etsu Chemical Co., Ltd.), trade name “KE1833” (viscosity (25 ° C.) 150 Pa · s, manufactured by Shin-Etsu Chemical Co., Ltd.)), condensed silicone RTV (for example, trade name “KE441”). (Viscosity (25 ° C.) 15 Pa · s, manufactured by Shin-Etsu Chemical Co., Ltd.)) and the like. As the acrylic adhesive, acrylic modified silicone resin (for example, trade name “Super X 8008” (viscosity (25 ° C.) 90 Pa · s, manufactured by Cemedine Co., Ltd.), trade name “Super X 8008 LL Black” (viscosity (25 ° C. ) 14 Pa · s, manufactured by Cemedine Co., Ltd.), trade name “Super X 8008 Clear” (viscosity (25 ° C.) 65 Pa · s, manufactured by Cemedine Co., Ltd.)), and the like. The fluid adhesive may be one-component or two-component, and may be thermosetting or moisture curable. Furthermore, the fluid adhesive may be adjusted using a diluent such as toluene and xylene so that the viscosity is within the above range.

  Moreover, since the elastic roller 1 may be used under heating, the adhesive preferably has heat resistance, and specifically has heat resistance of about 150 to 250 ° C. Is preferred. The heat resistance is measured by a softening temperature measurement method defined in JIS K 6833.

  Other properties required for the adhesive include tensile shear bond strength in a cured product of the adhesive. In this invention, the tensile shear bond strength in the cured product of the adhesive is 0.5 to 4 MPa. Preferably there is. When the tensile shear adhesive strength of the cured adhesive is within the above range, the sleeve 4 and the foamed elastic layer 3 are firmly bonded with a sufficient adhesive force. The tensile shear bond strength is measured according to JIS K 6249 using a cured product obtained by curing an adhesive as a test sample.

  Although the thickness of the adhesive bond layer 5 is not specifically limited, Usually, it is preferable to adjust to 10-300 micrometers, and it is especially preferable to adjust to 10-100 micrometers.

  An example of a method for manufacturing an elastic roller according to the present invention (hereinafter sometimes referred to as a manufacturing method according to the present invention) will be described below. In the manufacturing method according to the present invention, the roller base material 7 having the foamed elastic layer 3 on the outer peripheral surface of the shaft body 2 is placed in a pressure environment of 0.15 MPa or more and 0.48 MPa or less to compress and compress the foamed elastic layer 3. Then, the roller base material 7 obtained by compressing and compressing the foamed elastic layer 3 is inserted into the sleeve 4 to release the pressurized state of the pressure environment.

  In the manufacturing method according to the present invention, first, as shown in FIG. 3, a roller base body 7 having a foamed elastic layer 3 on the outer peripheral surface of the shaft body 2 is prepared.

  The shaft body 2 is made of, for example, a metal such as iron, aluminum, stainless steel, brass or an alloy thereof, a resin such as a thermoplastic resin or a thermosetting resin, and carbon black or metal powder as a conductivity-imparting agent for the resin. It is prepared in a desired shape by a known method using a material such as a conductive resin blended with a body. When the shaft body 2 is required to have conductivity, in addition to the metal and the conductive resin, the surface of the insulating core body formed of the resin or the like is plated by a regular method to thereby form the shaft body 2. Can be formed. Among the materials, a metal is preferable because it can easily impart conductivity, and free cutting steel, aluminum, or stainless steel is particularly preferable.

  The shaft body 2 may be coated with a primer layer on its outer peripheral surface as desired. The primer for forming the primer layer is dissolved in a solvent or the like as desired, and is applied to the outer peripheral surface of the shaft body 2 according to a conventional method such as a dipping method or a spray method, and is cured. The primer is not particularly limited. For example, alkyd resin, phenol-modified silicone modified alkyd resin, oil-free alkyd resin, acrylic resin, silicone resin, epoxy resin, fluororesin, phenol resin, polyamide resin, Examples thereof include urethane resins and mixtures thereof. If desired, a crosslinking agent for curing and / or crosslinking the resin can be used. Examples of such a crosslinking agent include isocyanate compounds, melamine compounds, epoxy compounds, peroxides, phenol compounds, and hydrogen siloxane compounds. Etc. The primer layer is formed with a thickness of 0.1 to 10 μm, for example.

  Next, in the method for manufacturing a roller according to the present invention, the rubber composition described later disposed on the outer peripheral surface of the shaft body 2 formed in this way is cured to form the foamed elastic layer 3. For example, the foamed elastic layer 3 is formed on the outer peripheral surface of the shaft body 2 by performing molding and heat curing simultaneously or continuously by a known molding method. The molding method of the rubber composition is not particularly limited as long as the rubber composition can be disposed on the outer peripheral surface of the shaft body 2, and is particularly limited to, for example, continuous vulcanization by extrusion molding, press molding, and molding by injection. It is not something. For example, when the rubber composition is an addition reaction type foamed silicone rubber composition described later, extrusion molding or the like can be selected as the molding method. The rubber composition forming the foamed elastic layer 3 will be described later.

  The curing conditions of the rubber composition are such that when the rubber composition disposed on the outer peripheral surface of the shaft body 2 is cured and contains a foaming agent, the curing condition is sufficient for the foaming agent to decompose or foam. It is well adjusted depending on the composition of the rubber composition, the type of foaming agent, and the like. For example, when the rubber composition is an addition reaction type foamed silicone rubber composition to be described later, the curing conditions are usually 100 to 400 ° C., particularly 200 to 400 ° C., several minutes to 1 hour, particularly A heating time of 5 minutes or more and 30 minutes or less is preferable in that the foamed elastic layer 3 can have independent cells having an average cell diameter in the above range and have a foaming rate in the above range.

  In the manufacturing method according to the present invention, the foamed elastic layer 3 thus cured can be secondarily cured as necessary. Although the secondary curing conditions are not particularly limited, for example, when the rubber composition is an addition reaction type foamed silicone rubber composition described later, the secondary curing conditions remain in the cured state, 180 to A heating temperature of 250 ° C., in particular 190 to 230 ° C., and a heating time of 1 to 24 hours, in particular 3 to 10 hours, are preferred.

  In the manufacturing method according to the present invention, the foamed elastic layer 3 formed as described above can be subjected to an elastic layer adjusting process as necessary. In the elastic layer adjustment processing, the foamed elastic layer 3 is adjusted to a desired size by using a machining device such as a polishing device, a grinding device, and a cutting device, or an instrument, and / or the foamed elastic layer 3 This is a process for adjusting the surface state to a desired state or the like. Examples of the elastic layer adjustment processing include polishing, grinding, and cutting.

  The foamed elastic layer 3 formed in this way has an outer diameter larger than the inner diameter of the sleeve 4 to be described later. For example, the foamed elastic layer 3 has an outer diameter of 100 to 105% with respect to the inner diameter of the sleeve 4. It is good that it has an outer diameter of 100 to 102%. When the outer diameter of the foamed elastic layer 3 is adjusted to the above range, the foamed elastic layer 3 rapidly shrinks in a pressure environment described later, and when the pressure environment is released, the foamed elastic layer 3 is quickly restored. .

  In this manner, the roller base body 7 shown in FIG. 3 in which the foamed elastic layer 3 is formed on the outer peripheral surface of the shaft body 2 can be manufactured.

  On the other hand, in the manufacturing method according to the present invention, the sleeve 4 is prepared. The sleeve 4 is formed of a cylindrical body having openings at both ends of the metal material. The sleeve 4 is adjusted to a thickness of 20 to 150 μm, for example, and the inner diameter thereof is smaller than the outer diameter of the foamed elastic layer 3. For example, the outer diameter of the foamed elastic layer 3 is smaller than the inner diameter of the sleeve 4. Thus, the adjustment is made so as to be in the range described later. The sleeve 4 is formed into a cylindrical body by, for example, a spinning method or an ironing method. The sleeve 4 is preferably adjusted so that at least the outer peripheral surface is smooth.

In the manufacturing method according to the present invention, an adhesive is applied to the outer peripheral surface of the foamed elastic layer 3 in the roller base body 7 as desired. This adhesive is applied uniformly to the outer peripheral surface of the foamed elastic layer 3, preferably to the outer peripheral surface of the foamed elastic layer 3. The method for applying the adhesive to the outer peripheral surface of the foamed elastic layer 3 is not particularly limited, and examples thereof include a spray method, a dipping method, a ring coater method, and a roll coater method. When the adhesive is applied to the outer peripheral surface of the foamed elastic layer 3, the adhesive can be appropriately diluted with a diluent or the like. The fluid adhesive can be uniformly and easily applied to the outer peripheral surface of the foamed elastic layer 3, and bubbles or the like is generated in the coating layer to which the adhesive is applied, or bubbles or the like are mixed. Etc. can be effectively prevented. As a result, the foamed elastic layer 3 and the sleeve 4 can be firmly bonded. The applied amount of the adhesive may be adjusted so that the thickness of the adhesive layer 5 falls within the above range. For example, in the case of a silicone composition, 0.01 to 0.1 g / cm ^2. Adjusted to degree.

  In the manufacturing method according to the present invention, the roller base material 7 to which an adhesive is applied as desired is then inserted into the metal sleeve 4 in a pressurized environment at room temperature or under heating.

  Specifically, the roller base material 7 is placed in a pressure environment of 0.15 MPa or more and 0.48 MPa or less, and the foamed elastic layer 3 of the roller base material 7 is pressurized and compressed. As an apparatus used at this time, it is possible to reduce the diameter of the foamed elastic layer 3 of the roller base body 7 and insert the roller base body 7 into the metal sleeve 4 with the diameter of the foamed elastic layer 3 reduced. Any device can be used, and examples thereof include a pressurizing device 10 shown in FIG. A pressure device 10 shown in FIG. 4 is installed inside a cylindrical casing 11 that houses the roller base body 7 and the sleeve 4 in series in the axial direction thereof, and in the vicinity of one opening of the casing 11. , A mounting member 15 for mounting the sleeve 4, closed end portions 12 and 13 for closing the opening portions at both ends of the housing 11, and insertion for inserting the roller base 7 housed in the housing 11 into the sleeve 4 The apparatus 20 and the pressurizer 14 which pressurizes the inside of the housing | casing 11 are provided.

  As shown in FIG. 4, the casing 11 is only required to accommodate the roller base body 7 and the sleeve 4 in series in the axial direction thereof. In the pressurizing device 10, the casing 11 is formed in a hollow cylindrical body. Has been. The mounting member 15 only needs to be able to support the sleeve 4 at a predetermined position. In the pressurizing device 10, the mounting member 15 protrudes from the inner peripheral surface of the housing 11 toward the center and supports the sleeve 4. A ring-shaped protrusion having a placement surface 16 is provided. The mounting member 15 is disposed in the vicinity of one opening in the housing 11, that is, when a closed end 13 is attached to the housing 11, a clamping member 24 described later is disposed between the mounting member 15 and the closing member 13. It is formed at a position where a sufficient space is defined. By the mounting surface 16 of the mounting member 15, the sleeve 4 is supported at a position where the roller base 7 supported by the insertion device 20 described later is inserted, preferably at a position coaxial with the roller base 7. Is done. The closed end portions 12 and 13 have a through hole that allows the insertion device 20 described later to move in the axial direction, for example, and can close both end openings of the housing 11. Is formed in a cylindrical body provided with a sealing member 17 in the through hole. The sealing member 17 hermetically seals the insertion device 20 and the closed end portions 12 and 13. The pressurizer 14 only needs to be able to pressurize the inside of the casing 11 closed by the closed end portions 12 and 13 to, for example, about 0.48 MPa. For example, a compressor or the like is employed.

  As shown in FIG. 4, the insertion device 20 supports the roller base body 7, the casing 11, the mounting member 15, the sleeve 4 supported by the mounting member 15, and the closed end 12 and 13, a pair of support shafts 21 and 22 that pass through, preferably coaxially, and can be moved back and forth in the axial direction, and the opposite ends of the support shafts 21 and 22 are connected to the shaft body 2 of the roller base body 7. It has clamping members 23 and 24 that fix the ends and support the roller base body 7. The clamping members 23 and 24 only need to be able to fix the end of the shaft body 2. For example, the clamping members 23 and 24 may be configured to grip and fix the outer peripheral surface of the shaft body 2. You may be comprised so that a surface may be clamped and fixed.

  As shown in FIG. 4, in the pressurizing method using the pressurizing device 10, the casing 11 and the closed end portions 12 and 13 are assembled, and the sleeve 4 manufactured as described above is placed on the mounting member 15. The sleeve 4 is placed at a predetermined position. Next, if desired, both ends of the shaft body 2 in the roller base body 7 provided with the foamed elastic layer 3 having an adhesive coated on the outer peripheral surface are fixed to the sandwiching members 23 and 24, and a pair of support shafts 21 and 22 is provided. The roller base 7 is sandwiched between the casing 11, the mounting member 15, the sleeve 4 supported by the mounting member 15 and the closed end 13, and the roller base 7 is inserted into the sleeve. 4 is arranged in series in the upstream direction, and the casing 11 is closed by the closed end 12 to assemble the pressurizing device 10.

  Subsequently, the pressurizer 14 is started and the pressure in the pressurizer 10 is adjusted to 0.15 MPa or more and 0.48 MPa or less. After the pressure in the pressurizing apparatus 10 reaches the pressure range, the pressure range is maintained for a certain period of time, preferably within 5 minutes. That is, the roller base body 7 is placed in the apparatus adjusted under the pressure environment for a certain period of time, preferably several seconds to 5 minutes, and particularly preferably several seconds to 3 minutes. The foamed elastic layer 3 is pressurized with gas or the like in the cell, and the cell itself shrinks, and the foamed elastic layer 3 also shrinks, so that the outer diameter gradually becomes smaller and smaller than the inner diameter of the sleeve 4. At this time, if the pressure in the apparatus is adjusted to 0.15 MPa or more and 0.48 MPa or less, the foamed structure in the foamed elastic layer 3 is damaged even in a pressurized environment, and cracks and breakage occur. It can be prevented from occurring. If the foamed structure in the foamed elastic layer 3 can be prevented from being damaged and cracking and breakage can be prevented, the physical properties, particularly the hardness, of the foamed elastic layer 3 will not change greatly before and after pressing. 3 can uniformly prevent the sleeve 4 from being deformed by being in pressure contact with the sleeve 4, and as a result, the elastic roller 1 having the smooth sleeve 4 can be manufactured easily and with good reproducibility. it can. The pressure in the pressurizing device 10 is preferably adjusted to 0.17 MPa or more and 0.48 MPa or less in that the foamed elastic layer 3 can be effectively prevented from being damaged, cracked and broken. It is particularly preferable that the pressure is adjusted to 0.2 MPa or more and 0.48 MPa or less. In the manufacturing method according to the present invention, the pressurization rate until reaching the pressure environment of the pressure is not particularly limited, but for example, if the pressurization rate is adjusted to 0.01 to 0.5 MPa / sec. Good. When the time for placing the roller base body 7 in the apparatus adjusted in the pressure environment exceeds 5 minutes, the cells in the foamed elastic layer 3 are damaged, cracked or destroyed, and the restoration rate of the foamed elastic layer 3 is increased. Therefore, after the roller base body 7 is inserted into the sleeve 4, the foamed elastic layer 3 may not be restored as desired, and a gap may be formed between the foamed elastic layer 3 and the sleeve 4. The sleeve 4 may be displaced with respect to the layer 3.

Further, the shrinkage rate of the foamed elastic layer 3 in the roller base body 7 when the roller base body 7 is placed in the pressure environment is adjusted according to the inner diameter of the sleeve 4 and the like. The shrinkage rate of the foamed elastic layer 3 is, for example, about 65 to 99.5% of the thickness (initial thickness) of the foamed elastic layer 3 at normal pressure. It is preferably 80% to 99% from the viewpoint that it does not give damage or the like and is excellent in the recoverability when the pressure is released. The shrinkage rate of the foamed elastic layer 3 is calculated as follows. First, a roller base body 7 is inserted into each of a plurality of master rings in which a plurality of master ring gauges having a predetermined inner diameter are arranged in series in order of increasing inner diameter, and the outer peripheral surface of the foamed elastic layer 3 in the roller base body 7 A test body holding a plurality of master ring gauges arranged in series is prepared. Next, in the pressure device 10, the pressure in the pressure device 10 is changed to shrink the foamed elastic layer 3 of the test body, and a master having an inner diameter corresponding to the degree of contraction of the foamed elastic layer 3. Drop the ring gauge in order. The thickness t ₁ (mm) of the foamed elastic layer 3 after shrinkage is obtained by using the inner diameter of the master ring gauge that has finally dropped as the outer diameter of the foamed elastic layer 3 after shrinkage in the roller base body 7. From the thickness t ₁ (mm) thus determined and the thickness t ₀ (mm) of the foamed elastic layer 3 before being reduced (reduced), the formula (t ₁ / t ₀ ) × 100 ( %), The shrinkage ratio of the foamed elastic layer 3 is calculated.

  In this manner, in a state where the outer diameter of the foamed elastic layer 3 is smaller than the inner diameter of the sleeve 4, the pair of support shafts 21 and 22 in the insertion device 20 are manually or automatically moved to the sleeve 4 side (in FIG. 4). The roller base body 7 supported by the insertion device 20 is inserted into the sleeve 4 as shown in FIG. At this time, the holding member 24 of the insertion device 20 has an outer diameter smaller than the outer diameter of the foamed elastic layer 3 and the mounting member 15 is installed at the above-described position. Then, it reaches the space defined between the mounting member 15 and the closed end 13. In this way, the roller base body 7 provided with the foamed elastic layer 3 coated with the fluid adhesive on the outer peripheral surface can be inserted into the sleeve 4.

  In the manufacturing method according to the present invention, the roller base body 7 is inserted into the sleeve 4 at room temperature or under heating. When the adhesive is applied to the outer peripheral surface of the foamed elastic layer 3, it is naturally heated below the curing temperature of the fluid adhesive. In consideration of operability and the like, the roller base body 7 is preferably inserted into the sleeve 4 at room temperature.

  In the manufacturing method according to the present invention, the adhesive that bonds the foamed elastic layer 3 and the sleeve 4 is applied to the outer peripheral surface of the foamed elastic layer 3 and / or the inner peripheral surface of the sleeve before the roller base body 7 is pressed. It is preferably applied. The adhesive is as described above.

In the manufacturing method according to the present invention, the pressurized state of the pressure environment is then released while maintaining the state in which the roller base material 7 with the foamed elastic layer 3 contracted is inserted into the sleeve. At this time, if the pressure state is released at a reduced pressure speed of 1 × 10 ³ Pa / sec or more and 5 × 10 ⁴ Pa / sec or less, bubbles are generated or mixed in the applied adhesive and inserted. The sleeve 4 can be prevented from shifting, and the foamed elastic layer 3 gradually expands while the uniform application state of the adhesive is maintained. Press evenly to the inner surface. In terms of effectively preventing bubbles from being generated or mixed in the applied adhesive and displacement of the inserted sleeve 4, the pressure reduction speed when releasing the pressure state is: It is particularly preferably 2 × 10 ³ Pa / sec or more and 3 × 10 ⁴ Pa / sec or less.

  In the manufacturing method according to the present invention, the roller base body 7 inserted into the sleeve 4 is then taken out from the pressure device 10 and allowed to stand under atmospheric pressure, if desired. Then, the foamed elastic layer 3 having a diameter smaller than the inner diameter of the sleeve 4 gradually expands or expands, and its outer peripheral surface comes into contact with the inner peripheral surface of the sleeve 4 (via an adhesive). Press contact. The time for allowing the roller base material 7 inserted into the sleeve 4 to stand still is appropriately selected depending on the pressure in the pressure environment and the time in which the roller base material 7 is placed in the pressure environment. It is.

  In the manufacturing method according to the present invention, when an adhesive is applied, the adhesive existing between the foamed elastic layer 3 and the sleeve 4 is cured. The conditions for curing the adhesive are selected according to the applied adhesive. When the adhesive is cured in this manner, no bubbles are present in the adhesive as described above, and therefore the adhesive is uniformly interposed between the foamed elastic layer 3 and the sleeve 4 and the foamed elastic layer. The adhesive penetrates into the cells 3 and the foamed elastic layer 3 and the sleeve 4 can be firmly bonded. As a result, even when the elastic roller 1 is mounted on the fixing device and the elastic roller 1 is rotated, the foaming elastic layer 3 can be prevented from being peeled off from the sleeve 4 by the rotational driving force. The rotation of the layer 3 and the rotation of the sleeve 4 can be synchronized, so that a high quality image can be formed. The apparatus for curing the adhesive only needs to be an apparatus that can realize the curing conditions, and examples thereof include various heaters such as an oven, a blow dryer, and an infrared heater, and various dryers.

  In this way, the elastic roller 1 can be manufactured. That is, according to the manufacturing method according to the present invention, the elastic roller 1 including the foamed elastic layer 3 formed on the outer peripheral surface of the shaft body 2 and the sleeve 4 provided on the outer peripheral surface of the foamed elastic layer 3 can be easily obtained. Can be manufactured. The elastic roller 1 manufactured by the manufacturing method according to the present invention maintains the foamed structure in the foamed elastic layer 3 as described above, and even when an adhesive is used, bubbles are present in the adhesive. Since it does not exist, a smooth sleeve 4 is provided on the outer peripheral surface of the foamed elastic layer 3.

  The elastic roller 1 manufactured by the manufacturing method according to the present invention includes the Asker C hardness in the foamed elastic layer 3 exposed by peeling the sleeve 4 formed on the outer peripheral surface, and the foamed elastic layer 3 ( That is, it has the foamed elastic layer 3 in which the difference from the Asker C hardness in the foamed elastic layer 3) before being reduced in diameter by pressurization or depressurization is within ± 3. In the manufacturing method according to the present invention, when the sleeve 4 is provided, even if the foamed elastic layer 3 is compressed under pressure, the foamed structure in the foamed elastic layer 3 may be damaged, cracked or broken. Since it is effectively prevented and the foamed elastic layer 3 can maintain the initial hardness, the foamed elastic layer 3 of the elastic roller 1 has an Asker C hardness difference within the above range. As a result, when the elastic roller 1 manufactured by the manufacturing method according to the present invention is mounted as a fixing roller on the fixing device of the image forming apparatus, a high-quality image can be stably formed. The difference in Asker C hardness is preferably within a range of ± 2.

The rubber composition forming the foamed elastic layer 3 may be a composition containing rubber, a foaming agent or a hollow filler, and various additives as required. For example, a cell in an independent cell state is formed. Preferred examples include foamed silicone rubber-based compositions and foamed urethane rubber-based compositions. In particular, the foamed silicone rubber-based composition capable of forming a cell in an independent cell state is excellent in heat resistance, durability, resistance to residual strain, etc., and is suitable for a high-speed operation of an image forming apparatus. It is. As such a foamed silicone rubber composition, an addition reaction type foamed silicone rubber composition is particularly preferred. As a hollow filler, what is necessary is just a filler which can form a cell, for example after hardening | curing a rubber composition, For example, polyorganosiloxane type spherical powder is mentioned. The polyorganosiloxane spherical powder may be a spherical powder made of polyorganosiloxane, and examples thereof include silicone powder. More specifically, a silicone rubber powder having a structure in which linear dimethylpolysiloxane is crosslinked, and having a structure in which a siloxane bond is crosslinked in a three-dimensional network represented by (CH ₃ SiO _3/2 ) _n Examples thereof include a powder of silicone resin such as so-called polymethylsilsesquioxane, and a powder of coated silicone rubber in which the surface of the silicone rubber is coated with silicone resin or the like.

  The addition reaction type foamed silicone rubber composition contains a vinyl group-containing silicone raw rubber, a silica-based filler, a foaming agent, an addition reaction crosslinking agent, an addition reaction catalyst, and a reaction control agent. An organic peroxide crosslinking agent, a heat resistance improver, and various additives may be contained.

  Examples of the vinyl group-containing silicone raw rubber include millable silicone rubber and heat-crosslinked silicone rubber (HTV: High Temperature Vulcanizing). These vinyl group-containing silicone raw rubbers have the property that a foaming agent and an addition reaction cross-linking agent can be easily kneaded with a roll mill or the like in a later step, and are used alone or in combination of two or more. Can be used.

Examples of the silica-based filler include a fumed silica or a precipitated silica having a reinforcing property, and a surface having a high reinforcing effect that is surface-treated with a silane coupling agent represented by a general formula RSi (OR ′) _3. A treated silica-based filler is preferred. Here, R in the general formula is a glycidyl group, vinyl group, aminopropyl group, methacryloxy group, N-phenylaminopropyl group, mercapto group or the like, and R ′ in the general formula is a methyl group or an ethyl group. . The silane coupling agent represented by the general formula can be easily obtained, for example, as trade names “KBM1003” and “KBE402” manufactured by Shin-Etsu Chemical Co., Ltd. Such a silica-based filler surface-treated with a silane coupling agent can be obtained by treating the surface of the silica-based filler according to a conventional method. The compounding amount of the silica-based filler is preferably 5 to 100 parts by mass with respect to 100 parts by mass of the vinyl group-containing silicone raw rubber. A silica type filler can be used individually by 1 type or in mixture of 2 or more types.

  The foaming agent may be any foaming agent conventionally used for foamed rubber. Examples of the inorganic foaming agent include sodium bicarbonate and ammonium carbonate. Examples of the organic foaming agent include diazoamino derivatives, azonitrile derivatives, azo And organic azo compounds such as dicarboxylic acid derivatives. Usually, an inorganic foaming agent is used when forming continuous cells in rubber, and an organic foaming agent is used when forming independent cells. In the elastic roller 1, the foaming agent is preferably an organic foaming agent in that it can form a cell in an independent cell state. An azo compound such as ronitrile is preferably used. In particular, dimethyl-1,1'-azobis (1-cyclohexanecarboxylate) can be preferably used. The blending amount of the foaming agent varies depending on the type of the foaming agent, but it is preferable to adjust the Asker C hardness of the foamed elastic layer 3 to 20 to 60. Specifically, for example, it may be 0.1 to 10 parts by mass, particularly 0.5 to 10 parts by mass with respect to 100 parts by mass of the vinyl group-containing silicone raw rubber. If the blending amount of the foaming agent is less than 0.1 parts by mass, sufficient cells may not be formed in the foamed elastic layer 3 to be formed. On the other hand, if it exceeds 10 parts by mass, the foamed silicone rubber As a result, the mechanical strength of the foamed elastic layer 3 may be lowered. When dimethyl-1,1′-azo-bis (1-cyclohexanecarboxylate) is selected as the foaming agent, the blending amount is 0.5-5 with respect to 100 parts by mass of the vinyl group-containing silicone raw rubber. The mass part is particularly good. A foaming agent can be used individually by 1 type or in mixture of 2 or more types.

  As the addition reaction crosslinking agent, for example, a known organohydrogenpolysiloxane can be used as an addition reaction type crosslinking agent having two or more SiH groups (SiH bonds) in one molecule. The organohydrogenpolysiloxane may be linear, cyclic or branched. The compounding amount of the organohydrogenpolysiloxane is preferably 0.01 to 20 parts by mass with respect to 100 parts by mass of the vinyl group-containing silicone raw rubber. An addition reaction crosslinking agent can be used individually by 1 type or in mixture of 2 or more types.

  The addition reaction catalyst includes, for example, a simple substance of Group 9 or 10 of the periodic table and a compound thereof, and more specifically, particulate platinum adsorbed on a carrier such as silica, alumina, or silica gel. Metals, platinum chloride, chloroplatinic acid, chloroplatinic acid hexahydrate and olefin or divinyldimethylpolysiloxane complexes, platinum-based catalysts such as chloroplatinic acid hexahydrate alcohol solutions, palladium catalysts, rhodium catalysts, etc. Can be mentioned. The addition amount of these addition reaction catalysts is sufficient as the catalyst amount, and is usually 1 in terms of the total amount of addition reaction type foamed silicone rubber composition in terms of the metal amount of Group 9 or Group 10 of the Periodic Table. It is good that it is -1,000 ppm, and it is especially good that it is 10-500 ppm. If the amount of addition reaction catalyst is less than 1 ppm in terms of the metal content of Group 9 or Group 10 of the Periodic Table, the crosslinking reaction of vinyl group-containing silicone raw rubber does not proceed sufficiently, and vinyl group-containing silicone Curing of the raw rubber may be insufficient. On the other hand, if it exceeds 1,000 ppm, the ability to accelerate the crosslinking reaction of the vinyl group-containing silicone raw rubber is not improved, and the economic efficiency may be lowered. An addition reaction catalyst can be used individually by 1 type or in mixture of 2 or more types.

  As the reaction control agent, known reaction control agents can be used without limitation, and examples thereof include methylvinylcyclotetrasiloxane, acetylene alcohols, siloxane-modified acetylene alcohol, and hydroperoxide. The compounding amount of the reaction control agent is preferably 0.1 to 2 parts by mass with respect to 100 parts by mass of the vinyl group-containing silicone raw rubber. The reaction control agents can be used alone or in combination of two or more.

  The organic peroxide cross-linking agent can be used alone to cross-link vinyl group-containing silicone raw rubber, but if used in combination as an auxiliary cross-linking agent for an addition reaction cross-linking agent, the physical properties of the silicone rubber, such as strength and strain, can be improved. improves. Examples of the organic peroxide crosslinking agent include benzoyl peroxide, bis-2,4-dichlorobenzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide, and 2,5-dimethyl-2,5-bis. (T-butylperoxy) hexane and the like. The compounding amount of the organic peroxide crosslinking agent is preferably 0.3 to 10 parts by mass with respect to 100 parts by mass of the vinyl group-containing silicone raw rubber. An organic peroxide crosslinking agent can be used individually by 1 type or in mixture of 2 or more types.

  The heat resistance improver may be any compound that improves the heat resistance of the foamed elastic layer 3, and examples thereof include carbon black, iron oxide (also referred to as bengara), cerium oxide, and cerium hydroxide. These can be used individually by 1 type or in mixture of 2 or more types.

The carbon black can be generally classified into furnace black, channel black, acetylene black, thermal black, etc. depending on the production method. However, if the content of sulfur, amine, etc. is large, the addition reaction type foamed silicone rubber composition Since the addition reaction may be inhibited, carbon black having a low content of sulfur, amine, etc., for example, acetylene black is preferably used. Preferred examples of the iron oxide include black bengara (Fe ₃ O ₄ ) and red bengara (Fe ₂ O ₃ ). The cerium oxide and the cerium hydroxide may be used alone, but are used together with the carbon black and / or the iron oxide in that the change in hardness of the foamed elastic layer 3 can be suppressed. preferable.

  The total amount of the heat resistance improver is preferably 0.1 to 35 parts by mass, and particularly preferably 1 to 10 parts by mass with respect to 100 parts by mass of the vinyl group-containing silicone raw rubber. If the total blending amount of the heat resistance improver is within the above range, the blending amounts of carbon black, iron oxide, cerium oxide and cerium hydroxide are not particularly limited. For example, the compounding amount of the carbon black is preferably 0 to 15 parts by mass, more preferably 0.2 to 15 parts by mass with respect to 100 parts by mass of the vinyl group-containing silicone raw rubber. The mass part is particularly good. The blending amount of Bengala is preferably 0 to 30 parts by mass, more preferably 0.2 to 30 parts by mass, and 2 to 20 parts by mass with respect to 100 parts by mass of the vinyl group-containing silicone raw rubber. There is especially good. The blending amounts of cerium oxide and cerium hydroxide are preferably 0.1 to 5 parts by weight, particularly 0.2 to 2 parts by weight, based on 100 parts by weight of the vinyl group-containing silicone raw rubber. Good.

  The various additives include, for example, fillers such as calcium carbonate, colorants, flame retardant improvers, thermal conductivity improvers, release agents, alkoxy silanes, diphenyl silane diols, carbon functional silanes, Examples thereof include dispersants such as both-end silanol-blocked low-molecular siloxanes, and non-reinforcing silica such as pulverized quartz and diatomaceous earth that can adjust the hardness of the resulting rubber. These various additives are blended in a desired blending amount.

  As the silicone rubber composition containing the vinyl group-containing silicone raw rubber, the silica filler, and the various additives, for example, trade names “KE series” and “KEG series” manufactured by Shin-Etsu Chemical Co., Ltd. can be easily used. It can be obtained.

  The specific gravity of the rubber composition is not particularly limited, but since the specific gravity of the rubber composition also affects the density of the foamed elastic layer 3 to some extent, the specific gravity depends on the various rollers disposed in the image forming apparatus. Adjusted to The specific gravity of the rubber composition is usually preferably 1.00 to 2.00, more preferably 1.05 to 1.50.

  The rubber composition is, for example, several minutes to several hours, preferably 5 until it is uniformly mixed using a rubber kneader such as a two-roll, three-roll, roll mill, Banbury mixer, dough mixer (kneader) or the like. It is obtained by kneading at room temperature or under heating for 1 minute to 1 hour.

  The manufacturing method according to the present invention is not limited to the above-described manufacturing method, and various modifications can be made within a range in which the object of the present invention can be achieved. For example, in the manufacturing method according to the present invention, after the adhesive is applied to the outer peripheral surface of the foamed elastic layer 3 in the roller base material 7, the roller base material 7 is under a predetermined pressure environment. After the roller base is placed in a predetermined pressure environment, an adhesive may be applied to the outer peripheral surface of the foamed elastic layer in the roller base.

  Further, in the manufacturing method according to the present invention, an adhesive is applied to the outer peripheral surface of the foamed elastic layer 3 as desired. In this invention, in addition to the outer peripheral surface of the foamed elastic layer, the inner peripheral surface of the sleeve. You may apply | coat an adhesive agent to.

  Furthermore, the elastic roller 1 has the sleeve 4 as the outermost layer, but in the present invention, the sleeve does not have to be the outermost layer, and the sleeve may be formed at a position heated by the external heating means. Further, the elastic roller may include a heating body, for example, an electric heater, a heating coil, or the like, in the shaft body, in the elastic layer, or between the shaft body and the elastic layer, depending on the application.

  In the present invention, other layers such as an elastic layer, a release layer, a coat layer, a surface layer, and / or a protective layer may be formed on the outer peripheral surface of the sleeve 4 as desired. The elastic layer is a layer for ensuring elasticity and may be formed of various rubbers, and examples of the rubber include silicone rubber, urethane rubber, and fluorine rubber. The thickness of the elastic layer is preferably 20 to 500 μm, particularly preferably 100 to 400 μm. Further, the release layer is a layer for ensuring the releasability of the developer, and may be formed of various resins, coupling agents, etc. Examples of the resin include fluorine resin, silicone resin, urethane resin, and the like. Examples of the coupling agent include silane coupling agents. The thickness of the release layer is preferably 15 to 200 μm, particularly preferably 20 to 50 μm. The coat layer, the surface layer, and the protective layer are usually formed on the outer peripheral surface of the sleeve 4 in a thickness of 1 to 100 μm according to a conventional method. The material for forming the coat layer, the surface layer, and the protective layer is not particularly limited, but the elastic roller 1 is preferably a material that is not easily permanently deformed because it is in contact with or pressed against the contacted body. For example, alkyd resins, phenol-modified / silicone-modified alkyd resin modified products, oil-free alkyd resins, acrylic resins, silicone resins, epoxy resins, fluororesins, phenol resins, polyamide resins, urethane resins, polyamideimide resins, and the like And the like. In the present invention, the sleeve 4 is formed of silicone rubber on the outer surface of the single-layered cylindrical body formed of the metal material or the single-layered cylindrical body formed of the metal material. The laminate is preferably a laminate in which an elastic layer and a release layer formed of a fluororesin are laminated in this order.

  The pressure device 10 used in the manufacturing method according to the present invention is configured to store one roller base body 7 and one metal sleeve 4 in series in the axial direction thereof. The pressure device used in the present invention accommodates a plurality of roller bases and a plurality of metal sleeves in series in the axial direction thereof, and the roller bases inserted into the metal sleeves. You may be comprised so that two or more can be formed at once or continuously.

  The elastic roller 1 is disposed, for example, as the fixing roller 61 built in the image forming apparatus 40 shown in FIG. 6, more specifically, the fixing device 60 of the image forming apparatus 40.

  As shown in FIG. 6, the image forming apparatus 40 according to the present invention includes a rotatable image carrier 41 on which an electrostatic latent image is formed, for example, a photosensitive member, and abuts or presses against the image carrier 41 or A charging unit 42 that charges the image carrier 41, for example, a charging roller, and an exposure unit 43 that is provided above the image carrier 41 and forms an electrostatic latent image on the image carrier 41; A developing unit 50 which is provided in contact with or pressure contact with the image carrier 41 or at a predetermined interval, supplies the developer 52 with a constant layer thickness to the image carrier 41, and develops the electrostatic latent image; The transfer means 44 is provided so as to be pressed against the lower side of the image carrier 41 and transfers the developed electrostatic latent image from the image carrier 41 to the recording body 46, for example, a transfer roller, and downstream in the conveying direction of the recording body 46. The developer 52 (static A fixing device 60 for fixing the latent image) and a cleaning means 45 for removing the developer 52 not transferred to the recording body 46 and remaining on the image carrier 41 and / or dust adhering to the image carrier 41. Become.

  As shown in FIG. 6, the developing unit 50 has an opening at a position facing the image carrier 41, and is provided in the developer storage unit 51 that stores the developer 52 and the developer storage unit 51. Further, the stirrer 53 that uniformly stirs the developer 52 and the opening of the developer container 51 are provided in contact with or in pressure contact with the image carrier 41 or at a predetermined interval. A rotatable developer carrier 54 for supplying the developer 52 with a constant layer thickness, for example, a developing roller and a developer carrier 54 is provided above the developer carrier 54, and comes into contact with the developer carrier 54 to reduce the layer thickness of the developer 52. A developer regulating member 55 that regulates and charges the developer 52 by frictional charging, such as an elastic blade, is provided.

  As shown in FIG. 6, the fixing device 60 includes a fixing roller 61, a pressure roller 62 arranged to face the fixing roller 61, and a fixing roller in a housing 64 having an opening 65 through which the recording medium 46 passes. An external heating means 63 for heating 61 from the outside is provided, and the fixing roller 61 and the pressure roller 62 are rotatably supported so as to contact or press against each other. The pressure roller 62 is in contact with or in pressure contact with the fixing roller 61 by an urging means (not shown) such as a spring. The fixing device 60 is equipped with a heating coil as the external heating means 63 and employs an induction heating method. The heating coil as the external heating means 63 is a member having a length substantially the same as the axial length of the fixing roller 61, and is arranged substantially in parallel with the fixing roller 61 at a certain interval from the surface of the fixing roller 61. Has been. Although not shown, this heating coil is usually made of a ferromagnetic material such as ferrite and is formed into I-type, E-type, U-type, etc., which are typical shapes used for a switching power source, and a conducting wire is wound. It is made up of. When a high-frequency alternating current is applied to the conducting wire of the heating coil 63, an eddy current is generated in the sleeve 4 and the sleeve 4 is induction-heated by the Joule heat. As a result, the fixing roller 61 is heated.

  In the fixing device 60, the external heating means adopts, in addition to the induction heating method, a radiant heating method using a halogen heater and a reflector, a direct contact heating method in which heating is performed by directly contacting a heater or the like. The position where the external heating means is arranged is not particularly limited. The fixing device 60 may employ an internal heating unit instead of the external heating unit or in addition to the external heating unit.

  The image forming apparatus 40 operates as follows. First, as shown by an arrow in FIG. 6, the developer 52 and / or dust on the surface of the image carrier 41 are rotated by the cleaning unit 45 while the image carrier 41 rotates in the clockwise direction. Then, the image is exposed by the exposure means 43, and an electrostatic latent image is formed on the surface of the image carrier 41.

  On the other hand, in the developing means 50, the developer carrier 54 rotates in the direction of the arrow shown in FIG. 6, whereby the developer 52 is supplied to the developer carrier 54, and the supplied developer 52 is supplied to the developer carrier. Passing between 54 and the developer regulating member 55, it is regulated to a desired layer thickness and charged as desired.

  Next, a developer 52 having a desired layer thickness and charge amount is supplied to the image carrier 41 via the developer carrier 54, and the electrostatic latent image formed on the image carrier 41 is developed by the developer 52. This electrostatic latent image is visualized as a developer image. Next, the developer image developed on the image carrier 41 is transferred by the transfer unit 44 onto the recording body 46 conveyed between the image carrier 41 and the transfer unit 44. The recording body 46 to which the developer image has been transferred is conveyed to the fixing device 60 and heated when passing through a contact portion or a pressure contact portion between the pressure roller 62 and the fixing roller 61 heated by the heating coil 63. The developer image (electrostatic latent image) transferred by being pressed and / or pressed is fixed on the recording body 46 as a permanent image. In this way, an image can be formed on the recording body 46.

  Since the image forming apparatus 40 includes the elastic roller 1 having the smooth sleeve 4 on the outer peripheral surface of the foamed elastic layer 3 as the fixing roller 61, a high-quality image can be formed over a long period of time. .

  The image forming apparatus 40 is an electrophotographic image forming apparatus. However, in the present invention, the image forming apparatus is not limited to the electrophotographic system, and may be, for example, an electrostatic image forming apparatus. Good. Further, the image forming apparatus is a monochrome image forming apparatus in which only a single color developer is accommodated in the developing unit. However, in the present invention, the image forming apparatus is not limited to the monochrome image forming apparatus, and is a color image forming apparatus. It may be. Examples of the color image forming apparatus include a four-cycle color image forming apparatus that sequentially repeats primary transfer of a developer image carried on an image carrier to an intermediate transfer body, and a plurality of image carriers provided with developing means for each color. Examples thereof include a tandem type color image forming apparatus in which a body is arranged in series on an intermediate transfer body or a transfer conveyance belt. The image forming apparatus is, for example, an image forming apparatus such as a copying machine, a facsimile, or a printer.

Example 1
First, the shaft body 2 (diameter 12 mm × length 350 mm, SUM22) subjected to electroless nickel plating was washed with toluene, and a primer “No. 101A / B” (manufactured by Shin-Etsu Chemical Co., Ltd .: trade name) was used. Applied. The primer-treated shaft was fired at 180 ° C. for 30 minutes using a gear oven, and then cooled at room temperature for 30 minutes or more to form a primer layer.

  On the other hand, a silicone rubber composition “KE-904FU” (manufactured by Shin-Etsu Chemical Co., Ltd .: trade name) containing a vinyl group-containing silicone raw rubber and a silica-based filler, and an addition reaction crosslinking agent “C-153A” ( Shin-Etsu Chemical Co., Ltd .: trade name) 2.0 parts by mass, foaming agent azobis-isobutyronitrile “KEP-13” (Shin-Etsu Chemical Co., Ltd .: trade name) 2.5 parts by mass, and addition reaction An appropriate amount of platinum catalyst as a catalyst, 0.5 parts by mass of a reaction control agent “R-153A” (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.), and an organic peroxide cross-linking agent “C-3” (Shin-Etsu Chemical Co., Ltd.) Company: product name) Appropriate amount of heat resistance improver "KEP-12" (manufactured by Shin-Etsu Chemical Co., Ltd .: product name) 1.0 part by mass sufficiently with two rolls, addition reaction type A foamed silicone rubber composition A was prepared.

  Next, the shaft body 2 on which the primer layer is formed and the addition reaction type foamed silicone rubber composition are integrally extracted by an extruder, and then the addition reaction type foamed silicone is used by using an infrared heating furnace (IR furnace). The rubber composition was heated at 250 ° C. for 10 minutes to be foam-crosslinked, and the addition reaction type foamed silicone rubber composition was foam-crosslinked. Then, the addition reaction type | mold foaming silicone rubber composition after foaming bridge | crosslinking was further heated for 7 hours at 200 degreeC using the gear oven, and was left to stand at normal temperature for 1 hour. Next, the outer diameter of the formed elastic elastic layer 3 was adjusted to 29.1 mm with a cylindrical grinder. In this way, a roller base body 7 provided with the foamed elastic layer 3 was produced. The length of the foamed elastic layer 3 in the axial direction is 330 mm, the average cell diameter in the cells existing in the foamed elastic layer 3 is 400 μm, the average width of the cell wall is 0.15 mm, and the foaming rate of the foamed elastic layer 3 is It was 310%. The Asker C hardness of the foamed elastic layer 3 was 40.

  On the other hand, the pressurizing apparatus 10 shown in FIG. 4 was prepared. The casing 11, the closed end portions 12 and 13, the mounting member 15, the support shafts 21 and 22, and the sandwiching members 23 and 24 were each formed of S45C, and the sealing member 17 was formed of nitrile rubber. The casing 11 has an outer diameter of 55 mm, an inner diameter of 50 mm, and a length of 2200 mm. The closed end portion 12 has an outer diameter of 55 mm, an inner diameter of 50 mm, and a length of 1.5 mm. The closed end portion 13 has an outer diameter of 55 mm, an inner diameter of 10 mm, and a length. It was 30 mm. Furthermore, a sleeve (made of stainless steel (SUS304), thickness 40 μm, inner diameter 29.0 mm, length 330 mm, tensile strength 950 MPa) was prepared.

  Next, an adhesive (trade name “KE-1833”, viscosity (25 ° C.) 150 Pa · s, manufactured by Shin-Etsu Chemical Co., Ltd., heat resistance 150 is applied to the entire outer peripheral surface of the foamed elastic layer 3 in the roller base 7 produced. 10 g (° C., tensile shear bond strength: 1.0 MPa) (the thickness of the adhesive layer after curing was about 10 μm) was uniformly applied with a roll coater without diluting with a solvent.

Next, as shown in FIG. 4, the pressurizing device 10 was assembled, and the sleeve 4 was placed on the placement surface 16 of the placement member 15. Furthermore, both ends of the shaft body 2 in the roller base body 7 provided with the foamed elastic layer 3 coated with an adhesive are fixed to the clamping members 23 and 24, and the roller base body 7 is supported by a pair of support shafts 21 and 22. Is disposed in the casing 11 so that the roller base body 7 is in series in the upstream direction of the metal sleeve 4, the casing 11 is closed by the closed end 12, and the pressure device 10 is airtight. Assembled. Next, the pressurizer 14 was started, and the inside of the pressurizer 10 was pressurized at a pressurization speed of 1 × 10 ⁵ Pa / sec to reach a pressure of 0.3 MPa. This pressure was maintained for 1 minute, and the foamed elastic layer was pressurized and compressed. At this time, the shrinkage ratio of the foamed elastic layer was 91%. In a state where the foamed elastic layer 3 is compressed in this way, a pair of support shafts 21 and 22 of the insertion device 20 are manually advanced toward the metal sleeve 4 side, and as shown in FIG. The roller base body 7 supported by is inserted into the metal sleeve 4.

Next, the pressure environment in the pressure device 10 is released at a reduced pressure speed of 2 × 10 ⁴ Pa / sec, and the roller base material 7 inserted into the sleeve 4 is taken out from the pressure device 10. The roller base body 7 inserted in the was heated to 150 ° C. for 0.5 hour using a dryer (trade name “HIGH TEMPRATURE CHAMBER”, manufactured by Enomoto Kasei Co., Ltd.) to cure the adhesive. Thus, the elastic roller 1A was manufactured.

  Similarly, 30 elastic rollers 1A were manufactured. The difference in hardness of the foamed elastic layer 3 Asker C in this elastic roller 1A was calculated by the above method. Specifically, after peeling the sleeve 4 and the adhesive layer 5 of the elastic roller 1A to expose the foamed elastic layer 3, the Asker C hardness of the foamed elastic layer 3 exposed according to the above method is measured and measured. The difference between the Asker C hardness and the Asker C hardness in the foamed elastic layer 3 before being placed in a pressurized environment was calculated. As a result, the Asker C hardness of the foamed elastic layer 3 in the elastic roller 1A was in the range of “within ± 2” with respect to the initial hardness, and the change amount of the Asker C hardness was extremely small. It was expected that the foamed structure had no defects such as breakage. Further, when the presence or absence of bubbles in the adhesive layer 5 in the 30 elastic rollers 1A manufactured was confirmed by peeling the sleeve 4 of the elastic roller 1A, no bubbles were found in all the elastic rollers 1A. . Further, in the 30 elastic rollers 1A, no displacement of the sleeve 4 with respect to the foamed elastic layer 3 was observed.

(Example 2)
Thirty elastic rollers 1B were manufactured in the same manner as in Example 1 except that the pressure in the pressure device 10 was adjusted to 0.48 MPa. At this time, the shrinkage ratio of the foamed elastic layer 3 was about 83%. Various evaluations of the obtained elastic roller 1B were the same as those in Example 1.
(Example 3)
Thirty elastic rollers 1C were manufactured in the same manner as in Example 1 except that the decompression speed was adjusted to 1 × 10 ⁴ Pa / sec. Various evaluations of the obtained elastic roller 1 </ b> C were the same as those in Example 1.

Example 4
Thirty elastic rollers 1D were manufactured in the same manner as in Example 1 except that the roller base was placed in the pressure device 10 for 5 minutes. At this time, the shrinkage ratio of the foamed elastic layer 3 was about 90%. Various evaluations of the obtained elastic roller 1D were the same as those in Example 1.
(Example 5)
Thirty elastic rollers 1E were produced in the same manner as in Example 1 except that the roller base was placed in the pressure device 10 for 7 minutes. At this time, the shrinkage ratio of the foamed elastic layer 3 was about 85%. Various evaluations of the obtained elastic roller 1E were almost the same as the evaluations of Example 1, but one of the 30 elastic rollers 1E manufactured was displaced in the position of the sleeve 4 with respect to the foamed elastic layer 3. The reason for this is considered that the restoration rate of the foamed elastic layer 3 is low and a slight gap is generated between the foamed elastic layer 3 and the sleeve 4.

(Example 6)
Thirty elastic rollers 1F were manufactured in the same manner as in Example 1 except that the decompression speed was adjusted to 0.5 × 10 ³ Pa / sec. Various evaluations of the obtained elastic roller 1F were the same as those in Example 1, but one of the 30 elastic rollers 1F produced had a change in hardness of the foamed elastic layer 3 of “± 3”. .
(Example 7)
Thirty elastic rollers 1G were manufactured in the same manner as in Example 1 except that the decompression speed was adjusted to 6 × 10 ⁴ Pa / sec. Various evaluations of the obtained elastic roller 1G were almost the same as the evaluations of Example 1, but one of the 30 elastic rollers 1G manufactured was shifted in the position of the sleeve 4 with respect to the foamed elastic layer 3.

(Comparative Example 1)
Thirty elastic rollers 1H were manufactured in the same manner as in Example 1 except that the pressure in the pressure device 10 was adjusted to 0.50 MPa. At this time, the shrinkage percentage of the foamed elastic layer 3 was about 63%. In the same manner as in Example 1, the difference in Asker C hardness of the foamed elastic layer 3 in the elastic roller 1H was calculated. As a result, the Asker C hardness of the foamed elastic layer 3 in the elastic roller 1H has decreased by “4 to 6” with respect to the initial hardness, and the amount of change in the Asker C hardness was large. It was expected that defects such as breakage occurred in the structure. The presence or absence of bubbles in the adhesive layer 5 was confirmed by peeling the sleeve 4 of the elastic roller 1H, and the presence of bubbles was recognized in the five elastic rollers 1H. Further, displacement of the sleeve 4 with respect to the foamed elastic layer 3 was also recognized by the seven elastic rollers 1H.

(Comparative Example 2)
Thirty elastic rollers 1I were manufactured in the same manner as in Example 1 except that the pressure in the pressure device 10 was adjusted to 0.14 MPa. At this time, the shrinkage ratio of the foamed elastic layer 3 was about 99.7%. The Asker C hardness of the obtained elastic roller 1I was not changed as compared with the Asker C hardness of the foamed elastic layer 3 in the roller base body 7. In 10 elastic rollers 1I out of 30 elastic rollers 1I, the roller base material 7 could not be inserted into the sleeve 4, and the roller base material 7 could be inserted into the sleeve 4 In the five elastic rollers 1I out of the 20 rollers 1I, the position of the sleeve 4 with respect to the foamed elastic layer 3 was shifted. Thus, in Comparative Example 2, the elastic roller could not be easily manufactured with good reproducibility.

  Each of the thus-produced elastic rollers 1A to 1I (the elastic roller 1I is a roller in which the roller base body 7 can be quickly inserted into the sleeve 4) is shown in FIG. Attached to a testing machine, the deformation irregularity in the axial direction of the sleeve 4 and cracks at the axial end of the sleeve 4 were evaluated. This durability test apparatus 70 is fixed to the lower surface inside the casing, and includes a heating roller 71 provided with an internal heater 72, and external heaters 73 provided on both sides of the heating roller 71 along the axial direction. A test roller mounting portion 74 provided on the upper surface inside the housing so as to be movable up and down so as to face the heating roller 71, and a pressing force adjusting means 75 capable of moving the test roller mounting portion 74 up and down, for example, pressure adjustment A micrometer. As the heating roller 71, a metal (stainless steel (SUS304)) roller having a diameter of 20 mm was used.

  Each of the elastic rollers 1A to 1J is mounted on the bearing of the test roller mounting portion 74 as an elastic roller 76, and the pressing force adjusting means 75 is operated as shown in FIG. The elastic roller 76 is fixed so that the foamed elastic layer 3 of the elastic roller 76 is recessed by 3 mm at the press contact portion between the heating roller 71 and the elastic roller 76 (that is, the outer diameter of the elastic roller 76 is The distance d between the central axis of the elastic roller 76 and the central axis of the heating roller 71 was adjusted to be 3 mm shorter than the sum of the outer diameters of the heating roller 71).

  Next, the external heater 73 and the internal heater 72 were started, and the surface temperature of the heating roller 71 was adjusted to 180 ° C. Thereafter, the driving means (not shown) provided in the test roller mounting portion 74 is continuously operated at a rotational speed of 130 rpm for 100 hours, and after the recessed state of the foamed elastic layer 3 in the elastic roller 76 is released, the elastic roller 76 is moved to room temperature. Left for 24 hours.

  As a result, any of the elastic rollers 1A to 1G of Examples 1 to 7 has no deformation unevenness in the axial direction of the sleeve 4, and no cracks or the like are confirmed at the end of the sleeve 4 in the axial direction. For example, when 1G was mounted as a fixing roller on the fixing device of the image forming apparatus shown in FIG. 6, a high-quality image could be stably formed. In particular, in any of the elastic rollers 1A to 1D of Examples 1 to 4, even when the continuous operation time was further increased by about 50 hours, the deformation unevenness and cracks of the sleeve 4 were not confirmed. On the other hand, since any of the elastic rollers 1H of Comparative Example 1 was confirmed to have cracks or the like at the axial ends of the sleeve 4, these elastic rollers 1H and 1I are used as, for example, the image forming apparatus shown in FIG. It is expected that a high-quality image cannot be stably formed when the fixing device is mounted as a fixing roller. The elastic roller 1H of Comparative Example 2 had no deformation unevenness in the axial direction of the sleeve 4, and no cracks or the like were confirmed at the end of the sleeve 4 in the axial direction.

FIG. 1 is a schematic perspective view showing an embodiment of an elastic roller manufactured by the method for manufacturing an elastic roller according to the present invention. FIG. 2 is a schematic sectional view showing an embodiment of the elastic roller manufactured by the method for manufacturing an elastic roller according to the present invention. FIG. 3 is a schematic perspective view showing an embodiment of the roller original. FIG. 4 is a schematic explanatory diagram for explaining a state in which the roller base and the metal sleeve are accommodated in the pressure device. FIG. 5 is a schematic explanatory view for explaining a state in which the roller base is inserted into the metal sleeve in the pressurizing device. FIG. 6 is a schematic explanatory view showing an embodiment of the image forming apparatus according to the present invention. FIG. 7 is a schematic diagram showing a durability test apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Elastic roller 2 Shaft body 3 Foamed elastic layer 4 Sleeve 5 Adhesive layer 7 Roller base 10 Pressurizing device 11 Housing 12, 13 Closed end 14 Pressurizer 15 Mounting member 16 Mounting surface 17 Sealing member 20 Insertion Device 21, 22 Support shaft 23, 24 Holding member

DESCRIPTION OF SYMBOLS 40 Image forming apparatus 41 Image carrier 42 Charging means 43 Exposure means 44 Transfer means 45 Cleaning means 46 Recording body 50 Developing means 51 Developer storage part 52 Developer 53 Stirrer 54 Developer carrier 55 Developer regulating member 60 Fixing device 61 Fixing roller 62 Pressure roller 63 External heating means 64 Housing 65 Opening 70 Durability test device 71 Heating roller 72 Internal heater 73 External heater 74 Test roller mounting part 75 Pressure adjusting means

Claims (5)

A method for producing an elastic roller comprising a foamed elastic layer formed on an outer peripheral surface of a shaft body and a sleeve provided on the outer peripheral surface of the foamed elastic layer,
A roller base having a foamed elastic layer on the outer peripheral surface of the shaft is placed in a pressure environment of 0.15 to 0.48 MPa to compress and compress the foamed elastic layer, and the roller base is inserted into the sleeve. And releasing the pressurized state of the pressure environment.   The elastic roller manufacturing method according to claim 1, wherein the roller base is placed under the pressure environment for 5 minutes or less. ^{3. The} method for manufacturing an elastic roller according to claim 1, wherein the pressure state is released at a pressure reduction rate of 1 × 10 ^{3 to} 5 × 10 ⁴ Pa / sec.   A fixing device including an elastic roller manufactured by the method for manufacturing an elastic roller according to claim 1.   The image forming apparatus provided with the elastic roller manufactured by the manufacturing method of the elastic roller of any one of Claims 1-3.

Images