JP4094457B2 - Method for producing fluororesin-coated roller and fluororesin-coated roller - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing a fluororesin-coated roller and a fluororesin-coated roller, and more particularly, to obtain a fluororesin-coated roller for use in a fixing pressure roller of a fixing mechanism of an electrophotographic apparatus easily and with high quality. .
[0002]
[Prior art]
In an image forming mechanism of an electrophotographic apparatus such as a printer, a copier, or a facsimile, a fixing pressure roller is generally used when fixing an unfixed toner image on a transfer medium such as paper. In such a fixing mechanism, the transferred image onto which the unfixed toner image has been transferred is passed between two pressure-contacting fixing pressure rollers and heated to fix the toner image on the transferred material. .
[0003]
Conventionally, a rubber roller mainly made of heat-resistant rubber such as silicon rubber is used as the fixing pressure roller, but a fluororesin layer is provided on the surface side in order to prevent poor fixing of toner to paper. , Releasability is imparted. Examples of a method for producing a rubber elastic roller having such a fluororesin layer include the following methods.
[0004]
For example, liquid fluororesin paint is applied to the inner surface of the mold and fired to form a cylindrical cured film made of fluororesin on the inner surface of the mold, and then a roller core metal is inserted into the axis of the mold A method for producing a rubber elastic roller having a fluororesin layer by injecting a liquid rubber between a cured film and a metal core and performing thermal vulcanization of the rubber.
A method in which a fluororesin tube is coated on the surface of a roller in which a rubber layer or the like is formed on a metal core, and the fluororesin tube is heated and shrunk so that the roller and the tube are brought into close contact with each other to provide a fluororesin layer.
Examples thereof include a method of forming a fluororesin layer by applying and baking a liquid fluororesin paint on the surface of a roller having a rubber layer formed on a metal core.
[0005]
However, in the above-described liquid fluororesin coating method, since the firing temperature of the fluororesin is higher than the heat resistance temperature of the rubber layer, the rubber layer may deteriorate.
In the method using the above-described mold, when the roller is removed from the mold, a part of the fluororesin layer may be peeled off or wrinkles may be generated in the fluororesin layer. In addition, when a mold is used, there is a problem that the manufacturing cost increases.
Furthermore, in the method using heat shrinkage described above, wrinkles are likely to occur during heat shrinkage of the fluororesin tube, and the fluororesin layer may be difficult to thin.
[0006]
Therefore, various proposals have been made in addition to the above method according to the required performance of the roller. For example, in Japanese Patent Publication No. 8-15758 (Patent Document 1), one end of the PFA tube is placed in the decompression container. While holding and hanging, while sucking the gas in the decompression vessel from the other end side, a rubber roller having an outer diameter slightly larger than the inner diameter of the tube and coated with an adhesive on the outer peripheral surface is inserted, and the rubber roller and the tube There has been proposed a method of fitting a tube that integrates the two.
[0007]
Further, in Japanese Patent Laid-Open No. 10-244590 (Patent Document 2), one end of a PFA tube is held and suspended in an insertion mold, and the outer diameter is set slightly larger than that of the PFA tube. A rubber roller coated with an adhesive on the outer peripheral surface is brought into contact with the peripheral edge of the one end of the PFA tube, and the rubber roller is covered with a pressure vessel in an airtight state, and the inside of the pressure vessel is pressurized. There has been proposed a method for manufacturing a PFA tube-covered roller, wherein the rubber roller is inserted into the PFA tube and the adhesive is cured.
[0008]
[Patent Document 1]
Japanese Patent Publication No. 8-15758
[Patent Document 2]
Japanese Patent Laid-Open No. 10-244590
[Problems to be solved by the invention]
However, in the method of fitting a tube described in Japanese Patent Publication No. 8-15758 and the method of manufacturing a PFA tube-covered roller disclosed in Japanese Patent Application Laid-Open No. 10-244590, the rubber outer surface is smoothly inserted because the sliding between the outer surface of the roller and the inner surface of the tube is poor. However, when the rubber roller is inserted, there is a problem that the PFA tube is pulled by the rubber roller, the tube is damaged, the thickness is partially different, or the tube is wrinkled. Moreover, since a decompression container or a pressurized container is used, a complicated apparatus is required, and there is a problem that manufacturing takes time and cost.
[0011]
The present invention has been made in view of the above-described problems, and the fluororesin layer is not wrinkled, has a uniform thickness, and can easily manufacture a very high quality fluororesin-coated roller. It is an object to provide a method for producing a fluororesin-coated roller.
[0012]
[Means for Solving the Problems]
In order to solve the above problems, the present invention provides an inner peripheral surface of a fluororesin tube having an inner diameter smaller than an outer diameter of a roller base material and a tensile strength of 200 kgf / cm ² or more and / or an outer peripheral surface of the roller base material. A low-viscosity adhesive having a viscosity of 1000 cps to 10000 cps,
By expanding the diameter of the fluororesin tube, the fluororesin tube will be coated on the roller base material, the adhesive between the inner and outer circumferential surfaces of the roller base material of the fluororesin tube during coating The present invention provides a method for producing a fluororesin-coated roller, which is used as a lubricant by flowing .
[0013]
Thus, a low-viscosity adhesive is applied to the inner peripheral surface of the fluororesin tube and / or the outer peripheral surface of the roller base material, and the fluidity between the fluororesin tube and the roller base material is enhanced by the lubricating action of the adhesive. ing. For this reason, the roller base is expanded in the radial direction so that the outer peripheral surface of the roller base material is in contact with the inner peripheral surface of the fluororesin tube, and the inner diameter of the tube is the same as the outer diameter of the roller base material. The tube can be easily covered while sliding the material. Therefore, the fluororesin tube can be coated on the outer peripheral surface of the roller base material with a uniform thickness without being damaged when the roller base material is inserted.
[0014]
In addition, since the fluororesin tube having an inner diameter smaller than the outer diameter of the roller base material is expanded and coated, the tube does not wrinkle and the fluororesin tube and the roller base material can be securely adhered to each other. . Furthermore, even when there is a fold in the fluororesin tube obtained by extrusion molding or the like, the fold can be eliminated by expanding the tube. Therefore, a very high quality fluororesin-coated roller can be manufactured very easily even under normal pressure conditions with no pressure without using a pressure reducing / pressurizing device.
[0015]
The diameter of the fluororesin tube is expanded in the range of 2% to 20%, and this expansion is achieved by expanding the fluororesin tube by contact with the roller base material when the roller base material is coated, or before and after coating. It expands gradually with time. In this way, the tube diameter may be expanded at a time by contact with the roller base material during coating on the roller base material, or the tube diameter is expanded stepwise before coating, and then the tube with adhesive as a lubricant. May be coated.
[0016]
The diameter of the fluororesin tube is expanded in a range of 2% to 20%, and the roller base material is covered with the fluororesin tube. Thereby, favorable adhesiveness can be obtained at the time of insertion, maintaining smooth insertability.
The above range is that when the expansion of the tube diameter is smaller than 2%, the inner diameter of the tube and the outer diameter of the roller base material are substantially the same, and the adhesion between the tube and the roller base material This is because there is a case where there is insufficient. On the other hand, when the expansion of the tube diameter is larger than 20%, the tensile elongation is large, so that the tube may be wrinkled or broken.
Furthermore, the diameter of the tube is preferably expanded in the range of 5% to 15%.
[0017]
The viscosity of the adhesive is 10,000 cps or less, and the roller base material is made of rubber, resin, or metal. This is because when the viscosity of the adhesive is greater than 10,000 cps, it is difficult to smoothly insert the roller base material (cover the tube) when the material of the roller base material is difficult to insert such as rubber or resin. is there. The viscosity of the adhesive is preferably 7000 cps or less.
Although it is preferable that the viscosity is as small as possible, and the 1000cps or more from the viewpoint of compatibility with other performance such as adhesion performance.
[0018]
Specifically, an adhesive such as silicon or imide can be used.
Specific examples include silicon adhesive TSE-3221 manufactured by Toshiba Silicon Corporation.
For the adhesive, it is effective to make the adhesive layer thin and uniform by rubbing the surface of a fluororesin tube such as PFA with a roller or a spatula.
[0019]
The adhesive used in the present invention is preferably a thermosetting adhesive, and after the tube is coated on the roller base material at room temperature, the tube and the roller base material are bonded by heating to cure the adhesive. Can do. In addition, after apply | coating an adhesive agent, it is preferable to coat | cover a fluororesin tube as soon as possible, without drying.
[0020]
In order to improve the insertability of the roller base material, it is preferable to apply an adhesive over the entire inner peripheral surface of the fluororesin tube and the outer peripheral surface of the roller base material. You can also In some cases, an adhesive can be partially applied. The application state of the adhesive can be appropriately set depending on the type of adhesive, the material of the roller base material, and the like. The roller base material is preferably a cylindrical shaped body.
[0021]
The fluororesin tube is obtained by extrusion molding, and the material of the fluororesin tube is preferably tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA) from the viewpoint of heat resistance and the like. In addition, tetrafluoroethylene / hexafluoropropylene copolymer (FEP), polytetrafluoroethylene (PTFE), ethylene / tetrafluoroethylene copolymer (ETFE), polychlorotrifluoroethylene (PCTFE), ethylene / chlorotrifluoro Various fluororesins such as ethylene copolymer (ECTFE) and polyvinylidene fluoride (PVDF) can be used singly or in combination. Moreover, according to extrusion molding, a continuous long tube can be obtained stably.
[0022]
The thickness of the fluororesin tube is 50 μm or less . This is because if it is larger than 50 μm, the rigidity is increased and the tube is difficult to deform and is difficult to insert. Further, the thickness is set to 20 μm or more from the viewpoints of formability and performance when used as a roller. The inner diameter of the tube is preferably 10 mm to 200 mm.
[0023]
The roller base material is preferably inserted into the fluororesin tube under a pressure of 2 kg to 20 kg. As a result, the roller base material can be inserted more smoothly. This is because if it is smaller than the above range, it is difficult to insert the tube while expanding the diameter of the tube, and it takes time for the insertion. On the other hand, if it is larger than the above range, it is difficult to adjust the insertion length of the roller base material in the axial direction, and it may be difficult to cover the tube at a desired position.
[0024]
The tensile strength of the fluororesin tube 200 kgf / cm ² or more, preferably a 250 kgf / cm ² or more. This is because if the tensile strength is smaller than the above value, wrinkles or tears are likely to occur when the roller base material is inserted. It should be noted that the higher the tensile strength, the better if other required characteristics are satisfied.
[0025]
The tensile elongation of the fluororesin tube is preferably 200% to 400%. Thereby, insertion of a roller base material can be performed more easily.
[0026]
The length of the fluororesin tube in the axial direction is set so that an extra length is generated in the axial direction when the tube is covered, and the extra length of the tube is arranged on both sides of the roller base in the axial direction. It is preferable that the adhesive is heated and cured in a state where the tube is covered and the extra length portion is chucked. After the tube is coated on the roller base material, the both ends of the tube having an extra length in the axial direction are chucked to harden the adhesive, thereby improving the adhesion. In particular, the adhesiveness at the end of the roller base material in the axial direction can be enhanced. It should be noted that the tube and the roller base material can be set to have substantially the same length in advance, and it is sufficient that the tube completely covers the outer surface of the roller base material during coating.
[0027]
The inner peripheral surface of the fluororesin tube is preferably chemically modified by etching or plasma treatment. Thereby, the wettability of a fluororesin can be improved, adhesiveness with an adhesive agent can be improved, and favorable adhesiveness with a roller base material can be obtained. In addition to the above, surface treatment can also be performed by other surface modification methods such as ultraviolet irradiation, electron beam irradiation, ion irradiation, laser irradiation, corona discharge and the like.
[0028]
Further , a fluororesin tube manufactured by the fluororesin-coated roller manufacturing method of the present invention and having a tensile strength of 200 kgf / cm ² or more and a thickness of 50 μm or less and 20 μm or more is coated on the roller base material with an adhesive. It provides a fluororesin-coated rollers, characterized in that is.
As described above, the fluororesin-coated roller of the present invention has a uniform thickness of the fluororesin layer and is free from tears and scratches. Thus, since the surface of the fluororesin layer is coated with high accuracy, it can be particularly suitably used as a fixing pressure roller in a fixing mechanism of an electrophotographic apparatus.
[0029]
The roller base material to be coated with the fluororesin is not only made of rubber but also made of metal such as aluminum and SUS, made of resin such as polyimide, polyamideimide, polyphenylene sulfide, polyetheretherketone, polybenzimidazole, etc. be able to. Moreover, the surface of the cylindrical endless belt-like member on which the temporary shaft core is mounted can be covered with a fluororesin. By attaching a temporary shaft core to the inner peripheral surface side of a cylindrical endless belt made of polyimide resin or the like to form a roller-shaped member, and coating the surface of the roller-shaped member with a fluororesin, by removing the temporary shaft core, An endless belt coated with a fluororesin can also be obtained.
[0030]
Further, when the roller base material is a rubber roller, it is preferable to use silicone rubber, fluorine rubber or the like excellent in heat resistance, and various other rubber components can be appropriately mixed and used. Various additives may be blended as necessary, and foamed rubber can be obtained. When foamed rubber is used, it may be foamed during vulcanization or vulcanized after foaming. The rubber vulcanization may be performed after the tube coating or before the coating. A shaft made of metal such as aluminum, aluminum alloy, SUS, iron, or ceramic is preferably attached to the shaft center of the rubber roller.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a fluororesin-coated roller 10 of the present invention. The fluororesin-coated roller 10 includes a roller base material composed of a rubber roller 2 mainly composed of silicone rubber on which an aluminum shaft 1 is mounted, and a fluororesin layer composed of a fluororesin tube 3, and is used for fixing an electrophotographic apparatus. It is preferably used as a fixing pressure roller in the mechanism.
[0032]
Hereinafter, the manufacturing method of the fluororesin-coated roller 10 will be described in detail.
First, as shown in FIGS. 2 (A) and 2 (B), the entire surface of the inner peripheral surface 3a of the fluororesin tube 3 and the outer peripheral surface 2a of the rubber roller 2 having an inner diameter D3 smaller than the outer diameter D2 of the rubber roller 2 is low. A viscosity adhesive (not shown) is applied to form a lubricant. A thermosetting adhesive (TSE-3221 manufactured by Toshiba Silicon Co., Ltd.) was used as the adhesive, and the viscosity was adjusted to 5000 cps by dilution. The fluidity between the inner peripheral surface 3a of the fluororesin tube 3 and the outer peripheral surface 2a of the rubber roller 2 is enhanced by the lubricating action of the adhesive.
[0033]
The cylindrical fluororesin tube 3 has an inner diameter D3 of 32 mm and an axial length L3 of 350 mm. The cylindrical rubber roller 2 has an outer diameter D2 of 35 mm, an axial length L2 of 240 mm, and an outer diameter D1 of the shaft 1. Is 15 mm, and the axial length L1 is 280 mm. The fluororesin tube 3 is a PFA tube (manufactured by Gunze Co., Ltd.) obtained by extrusion molding, has a thickness of 30 μm, a tensile strength of 280 kgf / cm ² , and a tensile elongation of 300%.
[0034]
After the adhesive is applied, as shown in FIG. 3 (A), four ends of the fluororesin tube 3 (hereinafter also simply referred to as a tube) are provided at the end 3b so as to be even in the circumferential direction. The chuck 5 is attached. The other end side of the tube 3 is in a free state.
[0035]
The four chucks 5 attached to the tube 3 are pulled evenly in the radial direction, and the inner peripheral surface 3a of the tube 3 and the outer peripheral surface 2a of the rubber roller 2 are brought into contact with each other from the state before coating to expand the diameter of the tube 3. However, by inserting the rubber roller 2 into the tube from one end side of the tube 3, the tube 3 is covered on the outer peripheral surface 2a of the rubber roller 2 as shown in FIG. The tube 3 is covered so that the extra length portions 3c of the tube 3 are disposed on both sides of the rubber roller 2 in the axial direction.
[0036]
Specifically, while expanding the tube 3 so that the outer peripheral surface 2a of the rubber roller 2 and the inner peripheral surface 3a of the tube 3 are in contact with each other, the inner diameter D3 of the tube 3 is the same as the outer diameter D2 of the rubber roller 2, The rubber roller 2 is slid by the lubricating action of the adhesive and inserted into the tube 3, and the tube 3 is completely covered so as to cover the entire outer peripheral surface 2 a of the rubber roller 2. That is, the diameter of the tube 3 is expanded by about 9.4%, and the insertion force when the rubber roller 2 is inserted is 2 kg.
[0037]
After the tube 3 is coated on the rubber roller 2 under the normal temperature and normal pressure conditions as described above, as shown in FIG. 4 (A), an extra length is provided at both ends in the axial direction. The both ends of the extra length portion 3c of the tube 3 is chucked, and then heated at 150 ° C. to 250 ° C. for 1 hour to 3 hours to cure the adhesive and vulcanize the rubber.
[0038]
After the heating, as shown in FIG. 4 (B), the extra length portions 3c on both sides in the axial direction are cut, and the length of the tube 3 in the axial direction is made the same as the length of the rubber roller 2 to obtain the fluororesin-coated roller 10. Yes.
[0039]
Thus, since the low-viscosity adhesive is applied to the inner peripheral surface 3a of the tube 3 and the outer peripheral surface 2a of the rubber roller 2, the fluidity between the tube 3 and the rubber roller 2 is enhanced by the lubricating action of the adhesive. While expanding 3, the rubber roller 2 can be inserted into the tube 3 very smoothly. Therefore, the fluororesin tube 3 can be coated with a uniform thickness without the tube 3 being damaged during insertion.
[0040]
Further, since the fluororesin tube 3 having an inner diameter D3 smaller than the outer diameter D2 of the rubber roller 2 is expanded and covered by the above method, the tube 3 is not wrinkled, and the fluororesin tube 3 and the rubber roller 2 are It is possible to ensure close contact. Therefore, the very high quality fluororesin-coated roller 10 can be easily manufactured.
[0041]
The inner peripheral surface of the fluororesin tube needs to be subjected to etching treatment or plasma treatment in order to improve the adhesive force. The adhesive may be applied on one side of the tube side or the roller side. Note that an adhesive can be partially applied. The tube 3 can be expanded stepwise before and during coating.
[0042]
In the above embodiment, the roller base material is a rubber roller made of rubber, but may be made of metal, resin, or the like. In addition, as the roller base material, a cylindrical endless belt made of polyimide resin or nickel, iron or the like is also included, and by attaching an endless belt on the outer peripheral surface of the temporary shaft core, it becomes a roller shape, The tube can be coated. Moreover, each dimension of a fluororesin tube, a roller, etc. can be suitably set according to the performance etc. which are requested | required.
[0043]
【The invention's effect】
As is clear from the above description, according to the present invention, a low-viscosity adhesive is applied to the inner peripheral surface of the fluororesin tube and / or the outer peripheral surface of the roller base material, and the fluororesin is obtained by the lubricating action of the adhesive. The fluidity between the tube and the roller base material is enhanced. For this reason, while expanding the tube in the radial direction so that the outer peripheral surface of the roller base material is in contact with the inner peripheral surface of the fluororesin tube and the inner diameter of the tube is the same as the outer diameter of the roller base material, The material can be slid and inserted easily into the tube. As a result, the fluororesin tube can be coated with a uniform thickness and good adhesion without damaging the tube or generating wrinkles during insertion.
[0044]
In addition, the fluororesin tube obtained by extrusion or the like may be folded into a flat shape at the time of transportation or the like, and there may be a crease in the longitudinal direction of the tube. Thus, such fold marks can be eliminated, and a good image can be obtained when used as a fixing and pressing roller.
[0045]
Furthermore, the tube can be easily covered without using a large-scale device such as a decompression device or a pressurization device. Therefore, a very high quality fluororesin-coated roller can be manufactured very easily and inexpensively. As described above, the fluororesin-coated roller of the present invention can be particularly suitably used as a fixing and pressing roller in an image forming mechanism of an electrophotographic apparatus.
[Brief description of the drawings]
FIG. 1 is a schematic perspective view of a fluororesin-coated roller of the present invention.
2A is a schematic perspective view of a fluororesin tube, and FIG. 2B is a schematic perspective view of a rubber roller.
FIG. 3A is an explanatory diagram of a state of covering of a tube onto a rubber roller, and FIG. 3B is a view illustrating a state where the tube is completely covered.
FIGS. 4A and 4B are diagrams showing a part of a manufacturing process of a fluororesin-coated roller.
[Explanation of symbols]
1 Shaft 2 Rubber roller (roller base material)
2a Outer peripheral surface 3 Fluororesin tube (tube)
3a Inner peripheral surface D2 Outer diameter D3 Inner diameter

Claims (8)

Low viscosity with a viscosity of 1000 cps or more and 10000 cps or less on the inner peripheral surface of the fluororesin tube having an inner diameter smaller than the outer diameter of the roller base material and having a tensile strength of 200 kgf / cm ² or more and / or the outer peripheral surface of the roller base material. Apply the adhesive of
By expanding the diameter of the fluororesin tube, the fluororesin tube will be coated on the roller base material, the adhesive between the inner and outer circumferential surfaces of the roller base material of the fluororesin tube during coating A method for producing a fluororesin-coated roller, which is used as a lubricant by flowing .   The diameter of the fluororesin tube is expanded in the range of 2% to 20%. This expansion is achieved by expanding the fluororesin tube by contact with the roller base material when the roller base material is coated, or before and after coating. The method for producing a fluororesin-coated roller according to claim 1, wherein the fluororesin-coated roller is expanded step by step. Before coating the fluororesin tube on the roller base material without using a pressurizing device and a depressurizing device, the fluororesin tube is expanded by being pulled evenly in the radial direction with a chuck attached to the fluororesin tube. 3. The method for producing a fluororesin-coated roller according to claim 1, wherein the roller resin-coated roller is inserted while the outer peripheral surface of the roller base material is brought into contact with the inner peripheral surface of the fluororesin tube . The roller base material is made of rubber, resin, or metal ,
The method for producing a fluororesin-coated roller according to any one of claims 1 to 3, wherein the fluororesin tube is a PFA tube obtained by extrusion molding and has a thickness of 50 µm or less . The method for manufacturing a fluororesin-coated roller according to any one of claims 1 to 4, wherein an inner peripheral surface of the fluororesin tube is subjected to etching treatment or plasma treatment . The length of the fluororesin tube in the axial direction is set so that an extra length is generated in the axial direction when the tube is covered, and the extra length of the tube is arranged on both sides of the roller base in the axial direction. The method for producing a fluororesin-coated roller according to any one of claims 1 to 5, wherein the adhesive is heat-cured in a state where the tube is covered and the extra length portion is chucked . A fluororesin tube manufactured by the method according to any one of claims 1 to 6 and having a tensile strength of 200 kgf / cm ² or more and a thickness of 50 µm or less and 20 µm or more is provided with an adhesive on a roller base material. A fluororesin-coated roller that is covered with The fluororesin-coated roller according to claim 7, which is used as a fixing pressure roller in a fixing mechanism of an electrophotographic apparatus .

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