JP2008003265A - Silicone rubber roll, thermal fixing roller and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control elastic characteristics and thermal characteristics of an external surface layer into a predetermined distribution state in a roll body in which a silicone elastic layer and the external surface layer are successively formed around a shaft center member. <P>SOLUTION: The roll body having: the shaft center member made of metal and the like; a porous elastic layer made of silicone rubber formed around the shaft center member; and the external surface layer made of metal and the like and formed in a coating film state on the outer peripheral surface of the porous elastic layer is constituted as follows. The roll body is constituted of: the shaft center member formed to be columnar or cylindrical; a foundation roll body obtained by mixing a foaming agent in silicone rubber material and curing and molding it in cylindrical shape; and a surface sleeve body formed to be cylindrical of heat resistant material such as metal and the like. At such a time, a facing removing process for grinding or peeling a facing layer in molding which is formed on the surface is performed to the foundation roll body. The foundation roll body having a rugged surface from which the facing layer is removed is fixed in the surface sleeve body by press-fitting without using an adhesive. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roller for conveying paper sheets in various paper feeding devices or the like, a fixing roller for heating and fixing image-formed paper sheets, and a method for manufacturing the same, and a silicon rubber roll having excellent elasticity and thermal characteristics And improvement of the manufacturing method.

  In general, the roller body used in various paper feeding devices is used for the purpose of transporting paper sheets, the purpose of pressure-bonding paper sheets in the transport process, or the purpose of heating paper sheets in the transport process, etc. It is configured in various structures depending on the application. In particular, silicon rubber rolls are used in a wide range of applications as materials having excellent heat resistance, friction characteristics, elasticity at high temperatures, and the like. For example, Patent Documents 1 and 2 disclose thermal melting of toner inks formed on sheets. A silicone rubber roller is used as a fixing roller for fixing heat-sensitive ink.

  In the process of transporting such paper sheets, the roller body that performs ink fixing, etc., forms a shaft core member that constitutes the rotating shaft and an elastic layer such as silicon rubber around it, and a metal, resin film, etc. on its surface The mold release layer is formed. For example, Patent Document 1 (Japanese Patent Laid-Open No. 4-177282) discloses a roll structure in which a silicon rubber layer is formed around a cored bar as a fixing roller, and a porous foamed sponge layer of silica gel is formed around the core. . Patent Document 2 (Japanese Patent Laid-Open No. 5-94108) proposes a roller structure in which an elastic layer of silicon rubber is provided around the shaft core member, and a fluororesin sleeve is provided on the outer periphery thereof.

  However, with the recent increase in the speed of image forming apparatuses, there is a demand for a roll structure that has excellent responsiveness to reach the set temperature at a higher temperature and that does not change its outer diameter shape and elastic characteristics at high temperatures. In such a structure, the heat of the surface sleeve is propagated inside the silicon rubber and dissipated to the outside through the metal shaft core member, and there is a problem that the silicone rubber is thermally deformed due to the increase in the fixing temperature to cause fixing spots. .

  Therefore, in Patent Document 3 (Japanese Patent Laid-Open No. 21377871), an elastic layer of silicon rubber having a large number of bubbles is provided inside a heat generating sleeve formed on the surface, and heat is propagated by the bubbles mixed in the rubber layer. The heat of the outer surface layer is prevented from being lost, and at the same time, when the rubber layer undergoes thermal expansion (thermal change) at high temperatures, the deformation is absorbed by the internal bubbles to reduce the change in the outer shape. Attempts have been made.

  In this case, since the rotational force is applied to the shaft core member to rotate the sleeve of the outer surface layer, the silicon elastic body and the surface sleeve body need to be firmly fixed with an adhesive or the like. The publication does not disclose how to join the outer sleeve body and the silicon elastic body, but usually the silicon elastic body is vulcanized into a hollow cylindrical shape, and separately from this, metal or fluororesin The surface heating layer is formed into a sleeve shape by, for example, and both are fixed with an adhesive to be integrated.

In such a configuration, the heat of the surface heating sleeve is propagated to the internal silicon elastic body and released to the outside through the shaft core member. Therefore, the air layer having the lowest thermal conductivity is formed between the surface sleeve and the silicon elastic layer. For example, Japanese Patent Application Laid-Open No. 2005-49812 proposes a layer structure provided in In this publication, a proposal is made to reduce the heat dissipation from the outer surface layer by fitting an elastic body having a constricted portion that forms a gap to a metal surface sleeve body.
JP-A-4-177282 JP-A-5-94108 Japanese Patent Laid-Open No. 2-137871 JP 2005-49812 A

  As described above, when manufacturing a roll body having a layer structure in which an elastic layer such as silicon rubber is formed around the shaft core member and a release layer is formed on the surface thereof, conventionally, these are individually manufactured and bonded individually. It is integrated by fixing with an agent. For this reason, an adhesive layer and a rubber skin layer (interface layer) are interposed between the sleeve-shaped outer surface layer and the elastic layer of silicon rubber. Therefore, even if air bubbles are mixed in the elastic layer to prevent the heat of the outer surface layer from being released to the outside, the heat of the outer surface layer propagates to the entire outer periphery of the adhesive layer and the rubber skin layer, and is most heated. Propagated from the portion with low conductivity to the elastic layer and emitted to the outside from the shaft core member (mainly metal material). Even if the outer surface layer is locally heated by this phenomenon to fix the sheets efficiently, it takes time to raise the release layer, and fixing at a high speed lowers the fixing temperature and causes incomplete fixing. There was a problem.

  Such a phenomenon will be described with reference to FIG. 8. For example, when a rubber elastic body containing bubbles is produced by mixing a foaming agent in a silicon rubber material to form a rubber elastic body containing bubbles, a skin layer (interface) is formed on the surface of the rubber elastic body. This skin layer covers the entire surface of the elastic body with a skin-like, relatively dense, smooth surface. Therefore, the layer structure shown in FIG. 8 is obtained, and an adhesive layer 52 and a rubber skin layer 51b are formed between the film-like release layer 50 and the elastic rubber layer 51a containing bubbles.

  In such a conventional layer structure, first, the thickness of the adhesive layer becomes non-uniform, and the distribution of the elastic force applied to the surface release sleeve becomes non-uniform. The temperature distribution is non-uniform. In particular, when the adhesive is applied to the hollow inner wall of the release sleeve, the thickness of the applied layer becomes non-uniform. The variation in the thickness of the adhesive layer is caused by non-uniformity in the elastic characteristics of the outer surface layer and non-uniformity in temperature distribution. It leads to uniformity and causes fixed spots. Similarly, the shell-like rubber skin layer propagates the heat of the outer surface layer to the entire circumference of the roll body, and propagates from the portion with the highest thermal conductivity, for example, the portion with few internal bubbles into the rubber elastic layer, and the shaft core member such as metal. To the outside. As a result, the effect of bubbles formed in the rubber elastic layer (reduction of heat conduction) cannot be obtained, and even if the outer surface layer acts to heat and heat the part of the roller that acts on the heat fixing of the sheet, the heat is generated by the rubber. There has been a problem of being discharged from the elastic layer to the outside.

  Therefore, the present invention can manage the elastic body and the thermal characteristics of the outer surface layer in a predetermined distribution state in the roll body in which the silicon elastic layer and the outer surface layer are formed in this order around the shaft core member. The main subject is to provide a silicon rubber roll manufacturing method and a silicon rubber roll capable of stable heat-fixing or conveying paper sheets. Another object of the present invention is to provide a heat fixing roller in which the heat of the release layer is hardly transmitted to the internal rubber elastic body when the outer surface layer is heated.

  The present invention adopts the following configuration in order to solve the above problems. A metal or other shaft core member, a silicon rubber porous elastic layer formed around the shaft core member, and a metal or other outer surface layer formed into a film on the outer peripheral surface of the porous elastic layer. The roll body which has is comprised as follows. First, the roll body is a cylindrical member made of a cylindrical or cylindrical shaft core, a base roll body formed by mixing a foaming agent in a silicon rubber material and vulcanized into a cylindrical shape, and a metal or other heat-resistant material. And a surface sleeve body formed on the surface. At this time, the base roll body is subjected to skin removal processing for polishing or peeling the skin layer formed on the surface during molding. The base roll body having the uneven surface from which the skin layer has been removed is fixed by pressing into the surface sleeve body without using an adhesive. As a result, neither the adhesive layer nor the skin layer (skin layer) generated during the molding process of the elastic layer exists between the outer surface layer and the porous elastic layer, so that the heat applied to the surface layer is transferred from the inside of the elastic layer to the outside. The amount of heat released can be significantly reduced. At the same time, many bubbles are formed at the boundary between the surface layer and the elastic layer, and heat conduction into the elastic layer is further reduced by the air layer formed by the bubbles. Therefore, in the heat fixing roller, the warm-up time is shortened and the cooling time after use is also shortened.

  The foaming agent may be formed so that a plurality of bubbles are formed inside the base roll body to form a porous elastic layer, or a plurality of bubbles communicating with each other are linked inside the base roll body. The chained bubbles are configured so that at least a part thereof communicates with the outside air from the end face of the porous elastic layer. Thus, even if the temperature of the surface layer is raised to a high temperature or the elastic layer is thermally expanded, the air inside the bubbles leaks to the outside so that the outer shape of the roll is not changed and the sheet is pressed with a constant pressing force. Can be conveyed or fixed.

  Further, the heat fixing roller according to the present invention includes a metal or other shaft core member, a porous elastic layer of silicon rubber formed around the shaft core member, and a film on the outer peripheral surface of the porous elastic layer. A roll body having the formed metal or other outer surface layer is configured as follows. The roll body is formed into a cylindrical shape with a shaft core member formed in a cylindrical or cylindrical shape, a base roll body in which a foaming agent is mixed into a silicon rubber material and vulcanized into a cylindrical shape, and a metal or other heat-resistant material. The surface sleeve body is formed. The base roll body is press-fitted and joined to the surface sleeve body without using an adhesive in a state in which a skin removal process for polishing or peeling the skin layer formed at the time of molding is performed. This brings about the above-mentioned action.

  Further, the method for producing a silicon rubber roll according to the present invention includes a preformed metal or other shaft core member, a silicon rubber porous elastic layer formed around the shaft core member, and an outer periphery of the porous elastic layer. A method for producing a silicon rubber roll having a metal or other outer surface layer formed into a film on the surface, and a base roll body molding step in which a silicon rubber material containing a foaming agent is vulcanized into a hollow cylindrical shape, and the above molding The skin removal step of polishing or peeling the skin layer formed on the base roll body by the process, and the above-mentioned skin removal processing was applied to a metal or other surface sleeve body previously formed into a cylindrical shape in order to form the outer surface layer. A base roll body is comprised from the assembly process which press-fits and fixes without using an adhesive agent. In this processing, the base roll body is formed of a porous elastic layer in which a plurality of bubbles are formed. As a result, the process for forming the elastic layer of silicon rubber can be continuously formed, for example, by extruding into a tube shape, and can be mass-produced at low cost.

  In the assembling step, when the base roll body from which the skin layer is removed is press-fitted into the surface sleeve body, the shaft core member having a diameter larger than the hollow diameter is press-fitted into and fixed to the hollow of the base roll body. Thus, the press-fitting engagement between the base roll body and the surface sleeve body is maintained. As a result, the press-fit relationship between the outer periphery of the elastic layer and the surface layer can be maintained by the pressing force exerted on the inner cylinder of the elastic layer from the shaft core member.

  In the base roll body forming step, the shaft core member and the base roll body are formed by vulcanizing a silicon rubber material containing a foaming agent into a hollow cylindrical shape around the shaft core member coated with an appropriate adhesive. In the skin removing step, the skin layer of the base roll body is removed by a cylindrical grinder around the both ends of the shaft core member.

  The method for producing a silicon rubber roll according to the present invention includes a tube-shaped elastic roll formed by drawing or the like when a porous elastic layer of silicon rubber is formed between a shaft member such as metal and a sleeve-shaped outer surface layer. After creating the body, polishing or peeling the surface of this roll body and applying a satin finish, the outer surface layer is formed by press-fitting and fixing to the surface sleeve forming the outer surface layer. The porous elastic roll body is fixed in a pressure contact state, and a large number of fine bubbles are formed between the outer surface layer and the elastic roll body, and on the roll peripheral surface such as an adhesive layer or a rubber shell layer. Since there is no heat transfer layer, it is possible to significantly reduce the heat of the outer surface layer from being dissipated to the outside.

  Therefore, when configured as a heat fixing roller, the outer surface layer can be heated to a higher temperature, locally heated, heated in a short time, or cooled. At the same time, since the outer surface layer and the elastic roll body are in close contact with each other on the matte surface, the rotational force applied to the roll body is reliably transmitted to the outer surface layer, and there is no risk of slippage therebetween.

  Furthermore, since a plurality of bubbles communicating with each other are formed in a chain on the rubber elastic layer, and at least a part of the bubbles communicates with the outside air from the end face of the roll body, the outer surface layer can be heated to a high temperature. When the internal rubber elastic layer expands, the air inside the bubbles is pushed out, so there is little change in the outer diameter shape of the roll body, and the elastic pressing force exerted on the outer surface layer can be kept substantially uniform. . At the same time, a plurality of bubbles communicating with each other are formed in a chain on the elastic roll body, so that it is easy to elastically deform both in the axial direction and in the radial direction, so the elastic roll body is press-fitted into the surface sleeve forming the outer surface layer. It is possible to easily fix both of them after the press-fitting.

  Furthermore, the shaft core member and the elastic roll body are configured to have substantially the same shaft diameter, and after the elastic roll body is fitted to the shaft core member, the outer surface layer sleeve is press-fitted into the outer periphery of the elastic roll body. Therefore, the inner periphery of the elastic roll body tightens the shaft core member, and the three members of the shaft core member, the elastic roll body, and the outer surface layer can be reliably bonded, and it is possible to provide a silicon rubber roll that is easy to manufacture and inexpensive. Is possible.

  As described above, the silicon rubber roll and the fixing roller of the present invention are formed by a layer structure of a porous elastic layer of silicon rubber and an outer surface layer on the outer periphery of the shaft core member, and the porous elastic layer is a skin layer ( (Skin layer) is polished or peeled and surface-finished and bonded, so that the heat of the outer surface layer does not propagate to the outer circumference of the roll body, and the porous elastic layer Since a large number of bubbles having low thermal conductivity are formed between the outer surface layer and the surface, the heat of the outer surface layer is rarely released to the outside. Therefore, in the case of the fixing roller, remarkable effects such as heating the outer surface layer to a higher temperature, heating locally, heating and heating in a short time, and cooling in a short time are possible. Play.

  The present invention will be described in detail below based on the illustrated embodiment. 1 to 4 show a layer structure of a silicon rubber roller according to the present invention, FIG. 1 is a perspective view thereof, FIG. 2 is a transverse sectional view of FIG. 1, and FIG. 3 is a longitudinal sectional view. FIG. 4 is a perspective view showing a layer cross-sectional structure, and FIG. 5 shows a method for producing a silicon rubber roll according to the present invention.

  First, the structure of the silicon rubber roll A according to the present invention will be described with reference to FIG. The silicon rubber roll A is composed of a shaft core member 1, a porous elastic layer 2 on the outer periphery thereof, and an outer surface layer 3 on the outer periphery thereof. The shaft core member 1 is formed of a steel material such as an aluminum alloy or a SUS steel material into a cylindrical shape or a columnar shape by, for example, drawing, and constitutes a rotating shaft of the silicon rubber roll A. The shaft core member 1 is made of a metal material or a synthetic resin material having mechanical strength for supporting the entire roller body with the outer shape Dy1. In this case, when used as a heat fixing roller, this shaft core member is preferably made of a material or shape and configuration having a cylindrical or cylindrical shape and high mechanical strength and simultaneously having as little heat capacity and thermal conductivity as possible.

  The porous elastic layer 2 is formed of a hollow cylindrical base roll body 21 made of a silicon rubber material, the hollow inner diameter Dx2 is a dimension to fit the shaft core member 1, and the outer diameter Dy2 ′ is the outer surface. The sleeve body 31 that forms the layer 3 is configured to fit. The base roll body 21 is foamed and vulcanized by mixing a foaming agent into an unvulcanized silicon rubber material such as an organic compound mainly composed of silica (Sio2).

  As a molding method, the above-described cylindrical shape is formed by mold injection molding, injection, compression, extrusion molding, etc., which will be described later. By such molding, a large number of internal bubbles 22 are formed in the silicon rubber base roll body 21 by foaming of the foaming agent, and the bubbles 22 have a plurality of independent fine cavities in the silicon rubber layer as shown in FIG. A distributed single-bubble elastic layer (closed cell) and a continuous-bubble elastic layer (open cell) in which a plurality of bubbles communicating with each other are distributed. The difference between the single-bubble elastic layer and the continuous-bubble elastic layer will be described later.

  The outer surface layer 3 is a fluororesin film that uses a rubber material having a predetermined friction coefficient when used as a rubber roll for conveying paper sheets, and prevents adhesion of toner ink when used as a heat fixing roller. Form. In the case of the fixing roller, the fixing roller is constituted by a sleeve body 31 in which a base of a conductive magnetic material such as stainless steel, nickel alloy, or copper alloy is coated with fluorine resin or the like. The sleeve body 31 is formed with an inner diameter Dx3 that fits to the outer periphery of the substrate roll body 21, and the outer diameter Dy3 is formed with a predetermined roll outer diameter.

  The above-described shaft core member 1, the porous elastic layer 2, and the outer surface layer 3 are integrated as follows to constitute the silicon rubber roll A. As described above, the shaft core member 1 is formed in a cylindrical or columnar shape having the outer diameter Dy1, and the porous elastic body layer 2 is formed by the hollow cylindrical base roll body 21 having the inner diameter Dx2 and the outer diameter Dy2 ′ as described above. The outer surface layer 3 is formed of a sleeve body 31 having an inner diameter Dx3 and an outer diameter Dy3.

  Therefore, first, the porous elastic layer 2 is subjected to skin removal processing by polishing or peeling a skin layer 23 (hereinafter referred to as “skin layer”; see FIG. 5B) formed at the time of molding. As shown in FIG. 4, the surface of the base roll body 21 from which the skin layer 23 has been removed is formed by a sponge-like uneven surface 24, and its outer shape is formed by Dy2. Therefore, in the respective processing steps of the shaft core member 1, the porous elastic layer 2, and the outer surface layer 3, it is molded so that Dy1> Dx2 and Dy2> Dx3. That is, the outer shape Dy1 of the shaft core member 1 is larger than the inner diameter Dx2 of the base roll body 21 into which the shaft core member 1 is fitted, and the outer shape Dy2 of the base roll body 21 is formed to be larger than the inner diameter Dx3 of the sleeve body 31 into which the shaft core member 1 is fitted. It is.

  Then, the shaft core member 1 is pressed into the base roll body 21 from which the skin layer 23 (skin layer) has been removed as described above. At this time, after applying the adhesive to the shaft core member 1, the base roll body 21 is inserted, or press-fitting without applying the adhesive. Next, the sleeve body 31 is pressed into the base roll body 21 without applying an adhesive. This press-fitting is performed by setting the outer diameter Dy2 of the base roll body 21 and the inner diameter Dx3 of the sleeve body 31 so that the sponge-like uneven surface 24 formed on the surface of the base roll body 21 and the inner wall of the sleeve body 31 are in close contact with each other and are not easily detached. Set. That is, they are press-fitted with a dimensional difference such that they are not separated by the pressing force acting on the sleeve body 31 and the rotational force transmitted from the shaft core member 1. The outer diameter Dy2 and the inner diameter Dx3 are preferably set by experiments or the like so that sufficient mechanical strength can be obtained and durability is taken into consideration.

  As described above, the silicon rubber roll A composed of the shaft member 1, the porous elastic layer 2, and the outer surface layer 3 that are integrated in a laminated manner as described above is used as a heat fixing roller as follows. As shown in FIG. 7, a sheet is fed from a sheet feeding unit to a printing unit such as an electrostatic drum 40, and a laser beam is irradiated from a laser emitter 41 on the electrostatic drum 40 to form an electrostatic latent image. A toner ink is attached to the latent image by the developing device 42. The toner image attached on the drum is transferred onto the sheet by the transfer charger 43.

  The toner image transferred in the sheet form in this way is fixed by being heat-pressed by the fixing roller 44. The fixing roller 44 is composed of a pair of pressure rollers 44a and 44b, and the surface of each roller is formed of an outer surface layer f1 such as the aforementioned fluororesin film to which toner does not adhere. The outer surface layer f1 is provided with an elastic layer f2 (the aforementioned porous elastic layer 2) in order to press the sheet uniformly. The elastic layer f2 preferably contains bubbles (closed cells or open cells) for the reasons described later. The elastic layer f2 is fitted with a shaft core member that constitutes the rotation shaft f3.

  At least one of the pair of press rollers 44a and 44b press-contacted with each other in such a configuration is equipped with a heating means 45. For example, the following method is adopted as the configuration of the heating means 45. The first method is a method of providing a heat generating layer (not shown) between the elastic layer f2 and the surface layer f1. A current is supplied to the heat generating layer to raise the temperature of the surface layer to a predetermined temperature.

  The second method is a method in which a cavity is formed in the elastic layer f2, and a heating element (unit) such as a ceramic heater is built in the cavity.

  The third method is an induction heating method. For example, one surface layer f1 (sleeve body in the above-described embodiment) of the pressure roller is formed of a conductive layer made of a conductive magnetic material such as iron, nickel, and SUS and its surface. It is composed of a fluororesin layer (for example, polyimide resin) that coats. An exciting coil is arranged on the outer periphery of the pressure roller and heated.

In the fixing roller 44 configured as described above, the base roll body 21 and the sleeve body 31 perform the following functions when the outer surface layer f1 is heated and heated by the heating means.
(1) The heating time and cooling time can be shortened (warming up time is shortened).
The heat applied to the outer surface layer 3 can be kept low in thermal conductivity when propagated to the porous elastic layer 2 inside the outer surface layer 3. That is, the sleeve body 31 forming the outer surface layer 3 and the base roll body 21 forming the porous elastic layer 2 are press-fitted and fixed without using an adhesive in a state where the skin layer (skin layer) 23 of the roll body is removed. Therefore, the surface of the porous elastic layer 2 is a sponge-like uneven surface 24 shown in FIG. FIG. 4A shows a case where single bubble bubbles are contained in the elastic layer, and FIG. 3B shows a case where open bubble bubbles are contained in the elastic layer 2.

  The air bubbles 22 a, combined with the internal air bubbles 22, suppress the thermal conductivity of the roll body 21 and have an effect of suppressing the heat of the surface layer 3 from being propagated into the roll body 21. Since the thermal conductivity of air is smaller than that of silicon rubber, a large number of fine bubbles 22a are formed between the surface layer 3 and the elastic layer 2 to reduce heat conduction. In particular, since the skin layer (skin layer) and the adhesive layer exist even if air bubbles are mixed in the elastic layer, the heat of the surface layer is transferred to the entire outer periphery of the roll body by the adhesive layer and the skin layer. The heat is released from the portion having the highest thermal conductivity of the body through the shaft core member. On the other hand, since the adhesive layer and the skin layer are not present, the heat emission is remarkably reduced.

(2) The thermal deformation of the roll body due to rapid heating and rapid cooling is improved.
Even if the outer surface layer 3 (sleeve body 31) is rapidly heated and cooled, there is little thermal deformation of the porous elastic layer 2 (base roll body 21), and a constant pressing force can always be applied to the sheet. By forming the internal bubbles 22 in the porous elastic layer 2, the change in the outer shape is reduced even if the silicon rubber layer is thermally expanded and contracted. On the other hand, when a skin layer (skin layer) exists as in the prior art, the air in the bubbles expands when the temperature is raised, but the skin layer does not completely seal the elastic layer, so that air is released to the outside. When the outer surface layer 3 is cooled (heating stopped) following the release of air, the air in the bubbles contracts, the elastic layer contracts, and a void is formed between the skin layer and the elastic layer. In the present invention, since the outer skin layer (skin layer) 23 is removed and the sleeve body 31 is fitted to the sleeve body 31 as described above, the sleeve body 31 is detached from the base roll body 21 due to rapid expansion and contraction of the air in the bubbles. Alternatively, the generation of wrinkles on the surface layer of the sleeve body 31 is prevented.

  Next, the manufacturing method of the silicon rubber roll A concerning this invention is demonstrated. Similar to the above, the silicon rubber roll A has a shaft core member 1 made of metal or other material, a porous elastic layer 2 formed on the outer periphery of the shaft core member 1, and an outer periphery of the porous elastic layer 2. The outer shape surface layer 3 is formed. The shaft core member 1 is formed as a cylindrical or columnar rotating shaft, the porous elastic layer 2 is formed as a base roll body 21, and the outer surface layer 3 is formed as a sleeve body 31.

[Create rotation axis]
The shaft core member 1 is formed in a cylindrical or extended shape with a material having high mechanical strength such as iron, aluminum alloy, and stainless steel. FIG. 5 (a) shows a case where it is formed in a columnar shape, and the processing method is an appropriate method such as drawing or extrusion.

[Creation of the base roll body 21]
A base roll body 21 constituting the porous elastic layer 2 is made of silicon rubber. For example, methyl silicon rubber (VMQ) in which a methyl group is bonded to polysiloxane or fluorosilicon rubber (FVMQ) in which a fluoroalkyl group is bonded to polysiloxane is formed into a cylindrical shape having the above-described inner diameter Dx2 and outer shape Dy2 ′. At this time, foaming agents (NR, EPDM, Si, NBR, FKM (fluorine-based), etc.) are added to form bubbles. In this case, it is selected according to the foaming agent whether closed cells are formed, open cells (chain of bubbles communicated with each other) are formed.

  The processing method includes injecting an uncrosslinked liquid silicon material (silicon compound) into the mold and heat vulcanizing, and then forming the base material that has been rolled into a sheet (calendering, etc.) into a cylindrical shape. Various methods are known, such as a method of heat vulcanization and a method of forming into a tube shape by extrusion and heat vulcanization. The base roll body 21 is formed by forming the above-described cylindrical body having the inner diameter Dx2 and the outer shape Dy2 'by any one of these methods.

  Next, the skin layer (skin layer) 23 formed on the surface of the base roll body 21 by secondary processing is removed. This removal is performed by, for example, polishing, and the outer shape is formed from Dy2 'to Dy2, and the sponge-like uneven surface 24 is formed on the surface.

[Creation of sleeve body 31]
The sleeve body 31 is formed according to the purpose of use. For example, when used as a sheet conveying roller, the sleeve body 31 is formed of a rubber material having a high friction coefficient. In the case of a heat fixing roller, a film-like sleeve is formed of a conductive magnetic material or the like. The outer shape Dy3 is formed to have a roll diameter required as a fixing roller, and the inner diameter Dx3 is set to Dx3 <Dy2 in relation to the outer diameter Dy2 of the base roll body 21.

[Assembly process]
The shaft member 1, the base roll body 21, and the sleeve body 31 created as described above are fitted and integrated. First, the shaft core member 1 is fitted to the base roll body 21 to fix them together. In this case, in the first method, an adhesive, for example, a thermosetting adhesive, is applied to the outer periphery of the shaft core member 1 and inserted into the hollow of the base roll body 21, and then heated and solidified. In the second method, the shaft core member 1 is pressed into the hollow of the base roll body 21 without using an adhesive. The former is set to Dy1≈Dx2, and the latter is set to Dy1 >> Dx2.

  Next, the base roll body 21 is press-fitted into the hollow of the sleeve body 31. At this time, both are press-fitted and fixed without using an adhesive. For this reason, the surface of the substrate roll body 21 has the skin layer (skin layer) 23 removed, and the sponge-like uneven surface 24 is deformed so as to be adsorbed to the inner wall of the sleeve body 31 as shown in FIG. A large frictional force acts. Moreover, the base roll body 21 from which the skin layer is removed is easily deformed in four directions, and the press-fitting work is facilitated.

The perspective explanatory view of the silicon rubber roll concerning the present invention. FIG. 2 is a cross-sectional view of the silicon rubber roll of FIG. 1. FIG. 2 is a longitudinal sectional view of the silicon rubber roll of FIG. 1. FIG. 3 is an explanatory perspective view showing a layer structure of the silicon rubber roll of FIG. 1. Explanatory drawing of the manufacturing method of the silicon rubber roll concerning this invention. It is explanatory drawing of the layer structure in the roll structure of FIG. 1, (a) is a cross-sectional structure at the time of containing a single bubble-like bubble in an elastic layer, (b) is the case at the time of making an open-cell bubble contained in an elastic layer. A cross-sectional structure is shown. FIG. 3 is a schematic explanatory diagram of a fixing roller in an image forming apparatus. Explanatory drawing of the layer structure of the conventional silicon rubber roll.

Explanation of symbols

A Silicon rubber roll Dx2 Inner diameter Dx3 of base roll body 21 Inner diameter Dy1 of sleeve body 31 Outer diameter Dy2 'of core member 1 Outer diameter of base roll body 21 (before polishing)
Dy2 Base roll body 21 outer diameter (after polishing)
Dy3 sleeve body 31 outer diameter 1 shaft core member 2 porous elastic layer 3 outer surface layer 21 base roll body 22 internal bubbles 22a bubbles 23 skin layer (skin layer)
24 Sponge-like uneven surface 31 Sleeve body 40 Electrostatic drum 44 Fixing roller 44a Pressure roller 44b Pressure roller f1 Outer surface layer f2 Elastic layer f3 Rotating shaft

Claims (7)

Metal and other shaft core members,
A porous elastic layer of silicon rubber formed around the shaft core member;
A roll body having a metal or other outer surface layer formed in a film shape on the outer peripheral surface of the porous elastic layer,
The roll body is
An axial core member formed in a cylindrical or cylindrical shape;
A base roll body in which a foaming agent is mixed into a silicon rubber material and vulcanized into a cylindrical shape,
A surface sleeve body formed in a cylindrical shape with metal or other heat-resistant material,
Consisting of
The base roll body is press-fitted and joined to the surface sleeve body without using an adhesive in a state in which a skin removal process is performed to polish or peel off a skin layer formed at the time of molding. Silicon rubber roll. 2. The silicon rubber roll according to claim 1, wherein the foaming agent forms a porous elastic layer by forming a plurality of bubbles in the base roll body. The foaming agent is formed so that a plurality of bubbles communicating with each other are linked inside the base roll body, and at least a part of the linked bubbles communicates with the outside air from the end face of the porous elastic layer. The silicon rubber roll according to claim 1. Metal and other shaft core members,
A porous elastic layer of silicon rubber formed around the shaft core member;
A roll body having a metal or other outer surface layer formed in a film shape on the outer peripheral surface of the porous elastic layer,
The roll body is
An axial core member formed in a cylindrical or cylindrical shape;
A base roll body in which a foaming agent is mixed into a silicon rubber material and vulcanized into a cylindrical shape,
A surface sleeve body formed in a cylindrical shape with metal or other heat-resistant material,
Consisting of
The base roll body is press-fitted and joined to the surface sleeve body without using an adhesive in a state in which a skin removal process for polishing or peeling the skin layer at the time of molding formed on the surface is performed,
A heat-fixing roller, wherein the outer surface layer formed of the surface sleeve body is provided with a heating means. A preformed metal or other shaft core member;
A porous elastic layer of silicon rubber formed around the shaft core member;
A method for producing a silicon rubber roll having a metal or other outer surface layer formed in a film shape on the outer peripheral surface of the porous elastic layer,
A base roll body molding process in which a silicone rubber material containing a foaming agent is vulcanized into a hollow cylindrical shape,
A skin removal step of polishing or peeling the skin layer formed on the base roll body by the molding step;
It comprises an assembly process in which a base roll body, which has been subjected to the above skin removal process, is formed on a metal or other surface sleeve body that has been previously formed into a cylindrical shape to form the outer surface layer, and is press-fitted without using an adhesive. And
The method for producing a silicon rubber roll, wherein the base roll body is formed of a porous elastic layer having a plurality of bubbles formed therein. In the assembling step, when the base roll body from which the skin layer is removed is press-fitted into the surface sleeve body, the shaft core member having a diameter larger than the hollow diameter is press-fitted into and fixed to the hollow of the base roll body. 6. The method for producing a silicon rubber roll according to claim 5, wherein the press-fitting engagement between the base roll body and the surface sleeve body is maintained. In the base roll body forming step, the shaft core member and the base roll body are formed by vulcanizing a silicon rubber material containing a foaming agent into a hollow cylindrical shape around the shaft core member coated with an appropriate adhesive. Is integrally molded,
6. The method for producing a silicon rubber roll according to claim 5, wherein in the skin removal step, the skin layer of the base roll body is removed with a cylindrical grinder around both ends of the shaft core member.

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