JP2000108223A - Manufacture of rubber-coated roller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a heat resistant resin tube or a metal tube of a roller base material by forming a film of a high heat resistant resin on an inner surface of a cylindrical mold, casting a foamable rubber material between the base material inserted into the mold and the film, and then vulcanizing to foam it. SOLUTION: A film 2 of a high heat resistant resin is formed on an inner surface of cylindrical mold 1, a roller base material 3 is coaxially inserted into a cylindrical wall in the mold, a foamable rubber material is cast between the material 3 and the film 2, sequentially or simultaneously foamed and vulcanized, and a rubber-coated roller 5 integrated with the film on its surface is removed from the mold. The used mold is preferably made of metal, but if its material has a heat resistance durable against a baking temperature of the resin of a fluororesin or the like, it is not limited to the metal. It is easy to draw the base material from the mold by incorporating good mold releasability in an inner surface of the mold.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a rubber-coated roller, and more particularly, to a method for manufacturing a rubber-coated roller in which a foamed rubber layer and a high heat-resistant resin layer are formed in this order on a roller substrate. About the method. The rubber-coated roller obtained by the manufacturing method of the present invention is suitable as a transfer roller, a developing roller, a charging roller, a pressure roller, a conveyance roller, and the like in an image forming apparatus such as an electrophotographic copying machine.

[0002]

2. Description of the Related Art Electrophotographic and electrostatic recording type copying machines,
2. Description of the Related Art In an image forming apparatus such as a facsimile or a laser beam printer, generally, a charging process for uniformly and uniformly charging a photosensitive drum, an exposure process for forming an electrostatic latent image on a photosensitive drum by performing image exposure, and a static process. A developing process of forming a toner image (visible image) by attaching toner (developer) to an electro-latent image, a transferring process of transferring a toner image on a photosensitive drum onto a transfer material such as transfer paper, and on a transfer material The image is formed by a fixing step of fixing the unfixed toner image.

In such an image forming apparatus, various roller members such as, for example, a fixing roller, a pressure roller, a conveying roller, a charging roller, and a transfer roller are disposed in each part of the apparatus. Is shared. These roller members are required to be excellent in heat resistance, releasability (anti-offset property), surface smoothness, durability, and the like, and have appropriate elasticity. Conventionally,
As these roller members, rubber-coated rollers in which a rubber layer is formed on a core metal and a fluororesin layer is further formed on the rubber layer are widely used. The roller member having such a structure is provided with an appropriate elasticity by a rubber layer, and is provided with a releasing property and heat resistance by a fluororesin layer. Recently, as a fixing roller, an endless belt-shaped roller member using a heat-resistant resin tube or a metal tube instead of the cored bar has been developed.

Conventionally, a method of manufacturing a roller member having the above structure is as follows. (1) A rubber layer such as silicone rubber is formed on an aluminum cored bar, and a fluororesin tube is put on the rubber layer. (2) A method in which a rubber layer such as silicone rubber is formed on an aluminum core, and a liquid fluororesin paint is applied on the rubber layer and baked to form a fluororesin layer ,
(3) A liquid fluororesin paint is applied to the inner surface of the cylinder wall of the mold, dried and fired to form a cylindrical cured thin film of the fluororesin on the inner surface of the cylinder wall, and then the inner surface of the cured thin film is etched. After that, a method is known in which a roller core is inserted into the axis of the cylindrical wall, and a liquid silicone rubber is press-fitted between the cured thin film and the core to thermally vulcanize the silicone rubber.

[0005] However, the method (1) has problems that wrinkles are easily generated when the fluororesin tube is heated and shrunk, and the thickness of the fluororesin layer cannot be reduced. According to the method (2), the sintering temperature of the high melting point fluororesin exceeds the heat resistance temperature of the rubber layer, so that the rubber layer is easily deteriorated, and the adhesion between the rubber layer and the fluororesin layer is not sufficient. In addition, there is a problem that a polishing step for both the rubber layer and the fluororesin layer is required. When the rubber layer is made of foamed rubber in order to further soften the rubber layer, it is difficult to grind the rubber for adjusting the dimensions of the formed rubber layer in the methods (1) and (2). Further, in the method (1), when the fluororesin tube is put on the foamed rubber layer and shrinked by heating, the surface is wavy, and the smoothness is impaired. In the method (2), there is a problem that the fluororesin paint enters the unevenness due to foaming on the surface of the foamed rubber layer and the film thickness is not uniform.

In the method (3), the rubber layer is not foamed rubber, and the outer resin is limited to a fluororesin. Further, it is essential to use a liquid fluororesin paint. I have. As described above, in the method (3), it is essential to use a liquid fluororesin paint, but the liquid fluororesin paint contains various additives such as a surfactant. For this reason, liquid fluororesin paint is usually applied to the inner surface of the mold, and after drying and firing, components such as surfactants contained in the liquid fluororesin paint are carbonized during firing and remain in the fluororesin cured thin film. I do. Therefore, the rubber-coated roller obtained by the method (3) has impurities remaining in the fluororesin layer on the surface.
The releasability of the toner is poor, which causes an offset phenomenon in an image. Furthermore, in the method (3), in the manufacturing process of the roller member, a part of the fluororesin cured thin film adheres strongly to the inner surface of the cylindrical wall due to impurities remaining in the fluororesin cured thin film, and as a result, the die When the rubber-coated roller is removed from the mold, there is a problem that a part of the fluororesin cured thin film is broken or wrinkles are generated, and surface smoothness is impaired.

In recent years, in order to cope with high-speed copying and full-color printing, for example, it is required that a pressure roller and a fixing roller have excellent elasticity and flexibility. In particular, when the flexibility of the pressure roller is improved, the toner formed on the transfer material such as transfer paper can be heated and melted and fixed so as to envelop the toner. Can be mixed and melted. However, as described above, when a foamed rubber layer is used in order to enhance the elasticity and flexibility of the rubber-coated roller, it is necessary to form a highly heat-resistant resin layer having surface heat resistance and release properties so as to be satisfactory. Becomes difficult.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to prevent deterioration of a rubber layer, tearing of a fluororesin layer and generation of wrinkles, flexibility, interlayer adhesion, heat resistance, mold release,
An object of the present invention is to provide a method of manufacturing a rubber-coated roller having excellent surface smoothness and durability. The present inventors have conducted intensive studies to overcome the problems of the prior art, and as a result, formed a coating of a highly heat-resistant resin such as a fluororesin on the inner surface of the cylindrical mold, and then formed the inside of the cylindrical mold. It has been found that the above-mentioned object can be achieved by inserting a roller base material into the base material, injecting a foamable rubber material between the roller base material and the high heat resistant resin film, and then performing vulcanization and foaming.

According to the method of the present invention, the surface of the high heat resistant resin film becomes smooth and has excellent mold release properties.
Further, in the method of the present invention, since the foamable rubber material is foamed inside the cylindrical mold, there is no need to grind the foamed rubber layer. Further, by smoothing the inner surface of the cylindrical mold, the surface of the high heat resistant resin can be smoothed. When a fluororesin is used as the high heat-resistant resin, a rubber-coated roller having excellent release properties and heat resistance can be obtained. As a method of forming a fluororesin coating, a method of applying a fluororesin powder to the inner surface of a cylindrical mold and firing it (powder coating method) is used, so that the surface activity is higher than when a fluororesin paint is used. No rubber or other impurities remain in the coating, and a rubber-coated roller with even better releasability can be obtained.

[0010] By activating the surface (inner surface) of the high heat resistant resin film formed on the inner surface of the cylindrical mold, the foamed rubber layer to be injection-molded later and the high heat resistant resin film are more firmly bonded to each other. It becomes possible. As another bonding method, a fluororesin-containing heat-resistant rubber material is applied to the surface of the fluororesin film formed on the inner surface of the cylindrical mold, and the fluororesin is heat-treated at a temperature equal to or higher than the melting point of the fluororesin. A method of fusing the coating and the heat-resistant rubber layer is also effective. In this case, in particular, by using a fluororesin contained in the heat-resistant rubber material as a fluororesin having a melting point of 305 ° C. or less, the heat-resistant rubber layer is reliably fused and adhered to the outer fluororesin layer under a relatively low temperature condition. be able to. In the present invention, the roller substrate is not limited to the cored bar, and the roller substrate can be a heat-resistant resin tube or a metal tube depending on the application. The present invention has been completed based on these findings.

[0011]

According to the present invention, a coating of a high heat-resistant resin is formed on the inner surface of a cylindrical mold, and then, a roller base material is inserted into the cylindrical mold. And vulcanizing and foaming after injecting a foamable rubber material between the rubber-coated roller and the highly heat-resistant resin film.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing a rubber-coated roller according to the present invention will be described with reference to FIG. A coating film 2 of a high heat-resistant resin is formed on the inner surface of a cylindrical mold 1 (a), and a roller base material 3 is inserted into the axis of a cylindrical wall in the cylindrical mold (b). After injecting the foamable rubber material 4 between the roller base material 3 and the high heat resistant resin film 2 (c), foaming and vulcanization are performed sequentially or simultaneously, and then the high heat resistant resin film is formed on the surface. The integrated rubber-coated roller 5 is released from the cylindrical mold (de). The cylindrical mold used in the present invention is
It is preferably made of a metal such as iron, stainless steel, or aluminum, but is not limited thereto as long as it has heat resistance that can withstand the firing temperature of a highly heat-resistant resin such as a fluororesin. In order to give the inner surface of this cylindrical mold good releasability, in the final step, the roller base material is removed from the cylindrical mold together with the highly heat-resistant resin layer including the fluororesin and the vulcanized foamed rubber layer. It is preferable because it is easy to pull out (remove the mold).

In order to give the inner surface of the cylindrical mold a releasability, it is preferable to perform a smoothing treatment on the inner surface. In order to smooth the inner surface of the cylindrical mold, for example, in the case of aluminum, a method of using a drawing material, or in the case of other materials, a method of performing a surface treatment such as chromium plating, nickel plating, or the like. is there. The surface roughness (Rz) of the inner surface of the cylindrical mold is preferably reduced to 20 μm or less by the smoothing treatment. More preferably, R
It is preferable that z is 5 μm or less. In addition to facilitating demolding by smoothing the inner surface of the cylindrical mold,
A highly heat-resistant resin layer including a fluororesin having excellent surface smoothness can be formed.

The size of the cylindrical mold is the length of a roller member such as a fixing roller (including a fixing belt) having a predetermined length, and the inner diameter is substantially equal to the outer diameter of the roller base material and the rubber layer. Is defined by the sum of the thicknesses of the two. The thickness of the cylindrical mold is appropriately determined in consideration of heat conduction at the time of sintering of a high heat-resistant resin such as a fluororesin and vulcanization and foaming of a foamable rubber material, but is usually 1 to 10 mm. It is preferred that it is about.
However, the preferred thickness is selected depending on the material. The high heat-resistant resin used in the present invention preferably refers to a resin having a heat resistance of 150 ° C. or higher for continuous use and a temperature of 200 ° C. or higher assuming that the resin is used in a high-temperature atmosphere such as a fixing roller. The high heat-resistant resin is not particularly limited, and examples thereof include a fluororesin, polyimide, polyamideimide, polyethersulfone, polyetheretherketone, polybenzimidazole, polybenzoxazole, polyphenylsulfide, and bismaleimide.

Examples of the fluororesin used in the present invention include polytetrafluoroethylene (PTFE), tetrafluoroethylene / perfluoroalkylvinyl ether copolymer (PFA), and tetrafluoroethylene / hexafluoropropylene copolymer (FEP). ), Ethylene / tetrafluoroethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene / chlorotrifluoroethylene copolymer (ECTF)
E), polyvinylidene fluoride (PVDF) and the like.

The fluororesin is preferably used in the form of a powder. These fluororesins can be used alone or in combination of two or more. When a rubber-coated roller is used as a pressure roller, a fixing roller, or the like, PTFE and PFA are preferable among these fluororesins from the viewpoint of heat resistance. Further, PFA is more preferable because it is easy to obtain a fluororesin coating having melt fluidity and excellent surface smoothness. The average particle size of the fluororesin powder is not particularly limited, but is 10 μm for forming a thin film having a uniform thickness by a powder coating method.
m or less. The lower limit is usually 1 μm
It is about. In particular, it is preferable to use PFA powder having an average particle diameter of 10 μm or less.

For coating the fluororesin powder, various general-purpose powder coating methods can be adopted. Among them, an electrostatic coating method of charging and applying the powder (electrostatic powder spraying) is preferred. Method) is preferable in order to form a uniform, well-tightened coating powder layer on the inner surface of the cylindrical mold.
After a fluororesin coating is formed on the inner surface of the cylindrical mold by a powder coating method, the fluororesin is fired according to a conventional method. The thickness of the fluororesin coating after firing is usually 0.1 to 150
μm, preferably 1 to 100 μm, more preferably 5 to
It is about 40 μm. By powder coating the fluororesin powder, a surfactant for dispersing the fluororesin particles in the liquid is not compounded as in the case of the liquid fluororesin paint, and pure fluororesin A coating can be formed. Thereby, since the carbonized impurities after firing do not remain in the fluororesin coating, a fluororesin layer excellent in surface smoothness and toner releasability can be formed.

In order to improve the adhesive strength between the highly heat-resistant resin layer such as a fluororesin and the foamed rubber layer, a highly heat-resistant resin film such as a fluororesin formed on the inner surface of the cylindrical mold is formed. It is preferable to perform a surface treatment. Surface treatment methods for highly heat-resistant resin coatings such as fluororesins include physical treatment by irradiation such as UV irradiation, excimer lamp, etc., UV irradiation, corona discharge, plasma treatment, electron beam irradiation, ion irradiation, laser irradiation, etc. Chemical treatment with metallic sodium; wet etching treatment with a treatment liquid; By these surface treatments, fluorine atoms are extracted from the surface of the highly heat-resistant resin film such as a fluororesin, or the surface is hydrophilized, so that the adhesive force with the foamed rubber layer is increased. In addition, an adhesive suitable for the material of the rubber layer can be applied to the surface of the high heat-resistant resin film such as a fluororesin.

The roller substrate used in the present invention is a roller core or a tube. Therefore, the rubber-coated roller of the present invention includes an endless belt-shaped roller member (for example, a fixing belt, a conveyance belt, and a charging belt) obtained by using a tube as a roller base material. As the roller-shaped metal core, generally, metals such as aluminum, aluminum alloy, iron, and stainless steel having good heat conductivity;
A cylindrical body formed of ceramics such as alumina and silicon carbide; and the like is used. As the tube, a heat-resistant resin tube or a metal tube is used. As the material of the heat-resistant resin tube, a material having a small heat capacity and quickly raising the temperature by heating the heater during use is preferable. As a specific example,
Examples include polyimide, polyamide imide, polyether ether ketone, polyphenylene sulfide, and polybenzimidazole. Among these, from the viewpoints of heat resistance and durability, thermosetting polyimide, polyamideimide, and polybenzimidazole are preferable, and polyimide is particularly preferable. The material of the metal tube is iron,
Nickel and alloys thereof are exemplified. When the electromagnetic induction heating method is adopted, iron, nickel, alloys thereof, ferritic stainless steel and the like are preferable. When it is necessary to efficiently heat the entire roller member like a fixing roller, it is particularly preferable to use a nickel tube capable of performing electromagnetic induction heating.

The thickness, length, etc. of the roller base material may be those conventionally used and are not particularly limited. For example, the length of the roller base material is appropriately determined according to the size of a transfer material such as transfer paper. In the case where a tube is used as the roller base material in each step of the present invention, in order to maintain the shape, for example, a support such as a stainless steel rod or tube is inserted into the tube and used. Can be. An adhesive suitable for the rubber material can be applied to the surface of the roller base material.

As the rubber used for the foamed rubber layer, a heat-resistant rubber such as silicone rubber and fluoro rubber is usually used. The heat-resistant rubber is, for example, a rubber having heat resistance enough to withstand continuous use at a fixing temperature when used for a fixing roller. As the heat-resistant rubber, a millable or liquid silicone rubber, a fluorine rubber, or a mixture thereof is preferable because heat resistance is particularly excellent. Specifically, silicone rubbers such as dimethyl silicone rubber, fluorosilicone rubber, methylphenyl silicone rubber, and vinyl silicone rubber; vinylidene fluoride rubber;
Fluororubbers such as tetrafluoroethylene-propylene rubber, tetrafluoroethylene-perfluoromethylvinylether rubber, phosphazene-based fluororubber, and fluoropolyether; Among these, it is preferable to use a liquid silicone rubber which is easily injected into a mold. These rubbers can be used alone or in combination of two or more.

In the present invention, a foamable rubber material containing a foaming agent in these rubbers is used. By using a foamable rubber material and vulcanized and foamed, excellent flexibility can be imparted to the rubber layer, and a pressure roller, a developing roller,
A rubber-coated roller suitable for a transfer roller or the like can be obtained. The foamable rubber material is obtained by blending a foaming agent in advance with liquid silicone rubber or the like, and is foamed simultaneously with injection or at the time of heat vulcanization. Therefore, in the present invention, vulcanization and foaming includes not only the case of foaming during vulcanization but also the mode of vulcanization after foaming. The foaming agent is not particularly limited, and examples thereof include a pyrolytic foaming agent such as sodium bicarbonate, an azo compound, and benzenesulfonyl hydrazide.

The foamable rubber material may include an inorganic filler such as carbon black, mica, and titanium oxide, if desired.
An organic filler such as a natural resin can be blended. The mixing ratio of the filler is usually 1 to 100 parts by weight of rubber.
It is at most 00 parts by weight, preferably at most 80 parts by weight. The thickness of the foamed rubber layer is appropriately set in consideration of the use, the structure of the mechanical device to be installed, the target elasticity, the hardness of the material to be used, and the like, but is usually 100 μm to 5 mm, preferably 0.1 μm.
About 3 mm. In order to bond the fluororesin and the foamed rubber layer, a heat-resistant rubber layer containing a fluororesin can be provided as an intermediate layer. After forming a fluororesin coating on the inner surface of the cylindrical mold, a heat-resistant rubber material containing a fluororesin is applied and heat-treated at a temperature equal to or higher than the melting point of the fluororesin, thereby forming a heat-resistant rubber layer to be formed. It is fused with the fluororesin layer.

As the heat-resistant rubber material, silicone rubber or fluorine rubber which can endure a high temperature corresponding to the melting point of the fluororesin even for a short time is preferable, but fluororubber is particularly preferable in terms of heat resistance. The fluororesin contained in the heat-resistant rubber material is not particularly limited, but a fluororesin that melts at a low temperature is preferable because the heat treatment temperature of the heat-resistant rubber material can be lowered. Among the fluororesins, it is more preferable to use a fluororesin having a melting point of 305 ° C. or lower. In particular, it is preferable to use PFA having a melting point of 305 ° C. or lower. The content of the fluororesin in the heat-resistant rubber material is not particularly limited, but is preferably 5 parts by weight or more with respect to 100 parts by weight of the heat-resistant rubber material from the viewpoint of fusing property with the outer layer of the fluororesin coating, 50 from the viewpoint of the flexibility of the heat-resistant rubber layer
It is preferable that the amount is not more than part by weight.

[0025]

The present invention will be described more specifically below with reference to examples and comparative examples. However, in these embodiments, the pressure roller is described, but in the present invention, the application of the roller is not particularly limited to the pressure roller, and may be applied to other applications such as a development roller, a transfer roller, and a fixing roller. Can also be used.

[Example 1] Inner diameter 24 mmφ, length 300
chrome-plated inner surface of an aluminum cylinder
A polyimide varnish (U Varnish S, manufactured by Ube Industries, Ltd.) is applied to the plating surface, dried and evaporated to remove the solvent.
Heat treated at 60 ° C for 60 minutes, polyimide coating (20μm thickness)
Was formed. A silicone adhesive DY39-
012 (manufactured by Dow Corning Toray Silicone Co., Ltd.) was applied and air-dried. Next, an aluminum core having an outer diameter of 20 mmφ and a length of 300 mm having the same silicone adhesive applied and dried on the surface was set in the cylinder so that the center of the cylinder coincided with the center of the core. A foamable rubber material obtained by mixing 5 parts by weight of sodium bicarbonate with liquid silicone rubber KE1380 (manufactured by Shin-Etsu Chemical Co., Ltd.) is poured into the gap between the cylinder and the core metal, and the rubber is vulcanized and foamed by heat treatment at 160 ° C. for 15 minutes. Was. Thereafter, the rubber-coated roller having the polyimide film formed on the surface was removed from the mold to obtain a pressure roller. The obtained pressure roller has no wrinkles or tears on the surface,
There was no wavy or uneven surface. The pressure roller was set in a fixing unit, and a roller in which a 2 mm-hardness JIS-A silicone rubber layer having a hardness of JIS-A 20 degrees and a 20 μm fluorine resin layer were sequentially laminated on an aluminum core was used as a fixing roller, and a halogen lamp heater was used. The temperature was raised so that the surface temperature of the fluororesin of the fixing roller became 180 ° C. An unfixed image formed by four color toners (C, M, Y, B) of a Canon copying machine was passed through a fixing unit, and was pressed at a nip width of 6 mm to continuously fix 10,000 sheets.
A good fixed image without offset was obtained up to the sheet. 1
After 000 sheets, the toner slightly adhered to the roller surface, and the roller was stained, but no offset was observed in which the fixed image was disturbed.

Example 2 Inner diameter 24 mmφ, length 300
chrome-plated inner surface of an aluminum cylinder
A PFA fluororesin paint AD-2CR (manufactured by Daikin) is applied to the plated surface, dried at 100 ° C. for 20 minutes, and then 380
Heat treated at 30 ° C for 30 minutes to form a fluororesin film (thickness: 20 µm)
Was formed. The inner surface was coated with a tetra-etch solution (manufactured by Junkosha Co., Ltd.), washed with water and etched. A silicone adhesive DY39-012 (manufactured by Toray Dow Corning Silicone Co., Ltd.) was applied to the inner surface and air-dried. Hereinafter, Example 1
In the same manner as in the above, a rubber-coated roller having a surface coated with a fluororesin film was obtained. This rubber-coated roller was used as a pressure roller and evaluated in the same manner as in Example 1. As a result, good fixed images without offset were obtained up to 5000 sheets. After 5,000 sheets, the toner slightly adhered to the roller surface, and the roller was stained, but no offset that caused disturbance in the fixed image was generated.

[Embodiment 3] Inner diameter 24 mmφ, length 300
chrome-plated inner surface of an aluminum cylinder
PFA fluororesin powder MP-102 (manufactured by DuPont) was powder-coated on the plated surface, and heat-treated at 380 ° C. for 30 minutes to form a fluororesin coating (thickness: 25 μm). Thereafter, the same operation as in Example 1 was performed to obtain a rubber-coated roller having a fluororesin film formed on the surface. This rubber-coated roller was used as a pressure roller and evaluated in the same manner as in Example 1. As a result, a good fixed image without offset was obtained until the end of 10,000 sheets.

[Embodiment 4] Inner diameter 24 mmφ, length 300
Chromium plating on the inner surface of an aluminum cylinder of 0.2 mm in diameter, PFA fluororesin powder MP-102 (manufactured by DuPont) is powder-coated on the plated surface, and heat-treated at 380 ° C. for 30 minutes.
A fluororesin film (thickness: 25 μm) was formed. On this inner surface, a fluoro rubber latex (Daiel GLS213, manufactured by Daikin) is coated with a PFA fluororesin (ACX
31, manufactured by Daikin) and 100 parts by weight of fluororubber, and then applied with 10 parts by weight of a paint, dried at 100 ° C.,
Heat treatment was performed at 320 ° C. for 10 minutes to fuse the fluoro rubber layer with the fluoro resin of the outer layer. A silicone adhesive DY39-012 (manufactured by Toray Dow Corning Silicone Co., Ltd.) was applied to the inner surface and air-dried. Thereafter, the same operation as in Example 1 was performed to obtain a rubber-coated roller having a fluororesin film formed on the surface. This rubber-coated roller was used as a pressure roller and evaluated in the same manner as in Example 1. As a result, a good fixed image without offset was obtained until the end of 10,000 sheets.

[Comparative Example 1] Inner diameter 24 mmφ, length 300
chrome plating on the inner surface of an aluminum cylinder
Next, an outer diameter 2 coated with a silicone adhesive and dried.
An aluminum core having a diameter of 0 mm and a length of 300 mm was set in the cylinder such that the center of the cylinder coincided with the center of the core. Liquid silicone rubber (KE1380, manufactured by Shin-Etsu Chemical) and sodium bicarbonate 5
Pour the foamable rubber material blended with
And then heat-treated for 15 minutes to vulcanize and foam the foamable rubber material, and then demolded. The surface of the foamed rubber layer was ground to make the surface uneven. PTFE fluororesin paint (EK4300, manufactured by Daikin) is applied to the surface of the foamed rubber layer, and 100
After drying at 20 ° C. for 20 minutes, heat treatment was performed at 380 ° C. for 10 minutes to form a fluororesin coating (thickness: 20 μm). As a result, in addition to the large unevenness of the rubber layer surface due to foaming,
The heat treatment deteriorated and shrunk the foamed rubber layer, causing severe irregularities on the surface. This pressure roller is set in a fixing unit, and a 2 mm hardness JIS
Using a roller in which silicone rubber having a temperature of −20 ° C. and a fluororesin having a thickness of 20 μm were sequentially laminated, the temperature of the fluororesin surface of the fixing roller was raised to 180 ° C. by a halogen lamp heater. 4-color toner (C,
When the unfixed image formed by M, Y, B) was passed through a fixing unit and continuously fixed by pressing with a nip width of 6 mm, the unevenness of the surface was severe, and the image was greatly disturbed from the first sheet and the color became dark and light. Severe variations occurred, and good images could not be obtained.

[Comparative Example 2] Inner diameter 24 mmφ, length 300
chrome plating on the inner surface of an aluminum cylinder
Next, an outer diameter 2 coated with a silicone adhesive and dried.
An aluminum core having a diameter of 0 mm and a length of 300 mm was set in the cylinder such that the center of the cylinder coincided with the center of the core. Liquid silicone rubber (KE1380, manufactured by Shin-Etsu Chemical) and sodium bicarbonate 5
Pour the foamable rubber material blended with
For 15 minutes to vulcanize and foam the foamable rubber material, and then demolded. The surface of the foamed rubber layer was ground to make the surface uneven. The surface of the foamed rubber layer was covered with a 50 μm-thick PFA shrinkable tube (manufactured by Gunze) and heat shrunk. As a result, the unevenness of the rubber due to foaming was originally large, and the unevenness was reflected on the surface of the fluororesin, and the unevenness was generated on the surface. This pressure roller is set in a fixing unit, and a roller in which silicone rubber having a hardness of 2 mm JIS-A20 degrees and a fluorine resin having a thickness of 20 μm are sequentially laminated on a cored bar is used as a fixing roller. The temperature was raised so that the resin surface temperature became 180 ° C. 4 color toners of Canon copier (C, M, Y, B)
Pass the unfixed image formed by
When the nip width was fixed at 6 mm and the image was continuously fixed, the unevenness of the surface was severe and the image was greatly disturbed from the first sheet.
Intense color variations occurred, and good images could not be obtained.

[Comparative Example 3] Inner diameter 24 mmφ, length 300
chrome plating on the inner surface of an aluminum cylinder
PTFE fluororesin paint (EK430)
0, manufactured by Daikin) and dried at 100 ° C. for 20 minutes.
Heat treatment at 380 ° C for 30 minutes to obtain fluororesin coating (thickness 20
μm). The inner surface was coated with a tetra-etch solution (manufactured by Junkosha Co., Ltd.), washed with water and etched. Next, a silicone adhesive DY39-012 (manufactured by Toray Dow Corning Silicone Co., Ltd.) was applied to the inner surface and air-dried. Outer diameter 2 coated and dried with the same silicone adhesive on the surface
An aluminum core having a diameter of 0 mm and a length of 300 mm was set in the cylinder so that the center of the cylinder coincided with the center of the core. Liquid silicone rubber (KE1380, manufactured by Shin-Etsu Chemical Co., Ltd.) was poured into the gap between the cylinder and the core metal,
The rubber was cured by heat treatment at 150C for 15 minutes. Thereafter, the rubber-coated roller was released from the cylinder. This pressure roller is set in a fixing unit, and a roller in which silicone rubber having a hardness of JIS-A of 20 mm and a fluororesin having a thickness of 20 μm are sequentially laminated on a core metal is used as a fixing roller. The temperature was raised so that the resin surface temperature became 180 ° C. When an unfixed image formed by four color toners (C, M, Y, B) of a Canon copier is passed through a fixing unit and continuously fixed by pressing,
Since the flexibility of the rubber was insufficient, the nip width was only 3 mm, the toner did not melt sufficiently, and a good image was not obtained from the first sheet.

[0033]

According to the present invention, flexibility, interlayer adhesion, heat resistance, releasability, surface smoothness, and durability can be achieved without causing deterioration of the rubber layer, tearing of the fluororesin layer, and generation of wrinkles. A method for producing a rubber-coated roller having excellent properties and the like is provided. The rubber-coated roller of the present invention is suitable as a pressure roller having excellent heat insulating properties, being flexible, having a smooth surface, and having excellent fixing properties and durability.

[Brief description of the drawings]

FIG. 1 is a process chart showing an example of a method for producing a rubber-coated roller of the present invention.

[Explanation of symbols]

 1: Cylindrical mold 2: High heat-resistant resin coating 3: Roller substrate 4: Foamable rubber material 5: Rubber-coated roller

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) G03G 15/20 103 G03G 15/20 103 4F213 (72) Inventor Toshihiko Takiguchi 1-chome Shimaya, Konohana-ku, Osaka-shi, Osaka No. 1-3 Sumitomo Electric Industries, Ltd., Osaka Works (72) Inventor Hiromi Uemura 950 Noda, Oji, Kumatori-cho, Sennan-gun, Osaka Sumitomo Electric Industries, Ltd.Kumatori Works (72) Inventor Chiaki Kato, Sennan-gun, Osaka No. 950, No.machi, F Sumitomo Electric Industries Co., Ltd. HA41 HA43 4F213 AA16 AA45 AB02 AC03 AC04 AD18 AG20 AH04 WA02 WA18 WA22 WA32 WA39 WA56 WA58 WA87 WB01 WB11 WC01 WF24 WF27

Claims (7)

[Claims] 1. A highly heat-resistant resin film is formed on the inner surface of a cylindrical mold, and a roller base material is inserted into the cylindrical mold. A method for producing a rubber-coated roller, comprising performing vulcanization and foaming after injecting a foamable rubber material. 2. The method according to claim 1, wherein the high heat-resistant resin is a fluororesin. 3. The method for producing a rubber-coated roller according to claim 2, wherein the inner surface of the cylindrical mold is coated with a fluororesin powder and fired to form a fluororesin coating. 4. The method according to claim 1, wherein a coating of a high heat-resistant resin is formed on the inner surface of the cylindrical mold, and then the surface of the coating is activated.
4. The method for producing a rubber-coated roller according to any one of items 3 to 3. 5. A fluororesin film is formed on the inner surface of a cylindrical mold, and a heat-resistant rubber material containing a fluororesin is applied on the inner surface of the fluororesin film, and heat-treated at a temperature not lower than the melting point of the fluororesin. To form a heat-resistant rubber layer fused with the fluororesin coating, and then insert the roller base material into the cylindrical mold, and put the foamable rubber material between the roller base material and the heat-resistant rubber layer. The vulcanization and foaming is performed after the injection.
4. The method for producing a rubber-coated roller according to item 1. 6. The method for producing a rubber-coated roller according to claim 5, wherein the fluororesin contained in the heat-resistant rubber material is a fluororesin having a melting point of 305 ° C. or lower. 7. The method for producing a rubber-coated roller according to claim 1, wherein the roller base material is a heat-resistant resin tube or a metal tube.