JP2008176028A - Method for manufacturing conductive rubber roller, roller for electrophotographic apparatus and transfer roller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a conductive rubber roller having a good C setting property and a uniform cell distribution of a rubber layer, free of unevenness in hardness and resistance, and useful as a roller for an electrophotographic apparatus, such as a transfer roller, a charging roller or a developing roller, by applying microwave vulcanization. <P>SOLUTION: Epichlorohydrin rubber copolymerized with an allyl glycidyl ether is used as a rubber component, 1-3 pts.mass of dipentamethylenethiuram tetrasulfide, 1-3 pts.mass of a thiuram disulfide compound and 0.5-1.5 pts.mass of a morpholinodithio compound, based on 100 pts.mass of the rubber component are used as a vulcanizing agent, the amount of sulfur added is confined to ≤0.2 pts.mass, and a chemical foaming agent is added to prepare a rubber composition. When the rubber composition is made foam, microwaves are used in a length of an irradiation zone of 1.8-2.0 m at an output of a microwave generator of 0.1-1.5 kW. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a conductive rubber roller used in an image forming apparatus such as an electrophotographic copying apparatus, a printer, and an electrostatic recording apparatus, and further to an electrophotographic process and an electrostatic recording process on an image carrier such as a photoreceptor. The present invention relates to a roller for an electrophotographic apparatus, such as a transfer roller of a transfer apparatus for transferring a transferable image formed by a toner image formed and supported by an image forming unit such as paper to a recording medium such as paper or a transfer material.

  In many electrophotographic image forming apparatuses (hereinafter, electrophotographic apparatuses) such as copying machines and printers, conductive rubber rollers such as a charging roller, a transfer roller, and a developing roller are used.

  Conventionally, these conductive rubber rollers are manufactured by inserting a conductive core material into a conductive foamed rubber tube or foaming a conductive rubber material around the conductive core material. The method of inserting the core material into the foamed rubber tube is preferable because it is simple and the rubber roller can be manufactured with high accuracy.

  Examples of methods for producing foam rubber tubes include vulcanization can vulcanization using high-pressure steam (Patent Document 1), mold vulcanization using a cylindrical mold (Patent Document 2), and microwave vulcanization using microwave irradiation (Patent Document 3). Are known.

  For example, in vulcanization can vulcanization, the cells of the foam are not uniform, and a large amount of polishing must be performed to bring the desired cells to the surface.

  In mold vulcanization, it takes time to set up, and it is necessary to perform mold cleaning, which is unsuitable for making many.

  On the other hand, microwave vulcanization provides good setup and uniform cells, but when the rubber is softened, the tube may be crushed and the aspect ratio of the inner and outer diameters of the tube may be non-uniform. Furthermore, due to this non-uniformity, the conductive rubber roller obtained has caused unevenness in circumferential hardness and resistance.

That is, in the production of foam rubber tubes in microwave vulcanization, in conductive rubber rollers used in future copying machines and printers, the aspect ratio of the foam cell and the inside / outside diameter of the tube is uniform, and the hardness and resistance in the circumferential direction are uniform. Therefore, there is a demand for a manufacturing method that is free from unevenness and has good setup and productivity.
JP 11-114978 A Japanese Patent Laid-Open No. 2002-221859 JP-A-11-201140

  Accordingly, an object of the present invention is to provide a transfer roller, a charging roller, and a developing roller that apply microwave vulcanization, have a good C-set property of a rubber layer, have a uniform cell distribution, and have no uneven hardness or resistance. The present invention provides a method for producing a conductive rubber roller useful as a roller for an electrophotographic apparatus, and the like, and a roller for an electrophotographic apparatus that is produced by the production method and that has no unevenness in hardness and resistance in the circumferential direction. That is.

  In order to solve the above-mentioned problems, the present inventors diligently studied rubber raw materials, microwave vulcanization conditions and the like, and finally reached the present invention.

  That is, the present invention relates to a method for producing a conductive rubber roller in which a foam rubber layer made of a rubber composition is formed on a conductive core material, wherein the rubber composition is copolymerized with allyl glycidyl ether as a rubber component. 1 to 3 parts by mass of a dipentamethylene thiuram tetrasulfide, 1 to 3 parts by mass of a thiuram disulfide compound, and morpholinodithio The compound contains 0.5 part by weight or more and 1.5 parts by weight or less, the amount of sulfur added is 0.2 part by weight or less, further contains a chemical foaming agent, and the microwave output of the rubber composition is 0. .1 kW or more and 1.5 kW or less, and irradiation with microwaves with an irradiation section length of 1.8 m or more and 2.0 m or less to form a foam. It is a manufacturing method of gender rubber roller.

  In addition, the present invention is the above-described method for producing a conductive rubber roller, wherein two microwave transmitters are used and the microwave irradiation amount is 0.2 kW or more and 3.0 kW or less.

  Furthermore, the present invention is the above-described method for producing a conductive rubber roller, wherein the chemical foaming agent is p, p'-oxybisbenzenesulfonyl hydrazide or azodicarbonamide.

  The present invention is also the above-described method for producing a conductive rubber roller, wherein the epichlorohydrin rubber contains an epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer.

  The present invention also provides a roller for an electrophotographic apparatus, which is a conductive rubber roller formed by the above-described method for manufacturing a conductive rubber roller.

The present invention also provides the rubber roller for an electrophotographic apparatus, wherein the resistance value measured in an environment of 23 ° C. × 55% RH is 5 × 10 ⁵ Ω or more and 5 × 10 ⁹ Ω or less.

  Furthermore, the present invention is the above-described roller for an electrophotographic apparatus, wherein a surface layer is further formed.

  According to another aspect of the present invention, there is provided a transfer roller which is the roller for an electrophotographic apparatus.

  The method for producing a conductive rubber roller of the present invention can provide a conductive rubber roller in which the foam rubber layer has a good C-set property, the cell distribution is uniform, and the hardness and resistance are not uneven. The conductive rubber roller manufactured by the method for manufacturing the conductive rubber roller can be suitably used as a roller for an electrophotographic apparatus, particularly as a transfer roller.

  The present invention is a method for producing a conductive rubber roller in which a foam rubber layer made of a rubber composition is formed on a conductive core material. The rubber composition is obtained by copolymerizing allyl glycidyl ether as a rubber component. In addition, 100 parts by mass of the rubber component is used, and 1 part by mass or more and 3 parts by mass or less of dipentamethylene thiuram tetrasulfide, 1 part by mass or more and 3 parts by mass or less of a thiuram disulfide compound as a vulcanizing agent The morpholinodithio compound is used in an amount of 0.5 parts by mass or more and 1.5 parts by mass or less, the sulfur content is 0.2 parts by mass or less, and contains a chemical foaming agent. The heating means is a microwave, and at least one microwave transmitter is provided in the microwave irradiation apparatus, and the microwave irradiation is performed. A less length 2.0 m (irradiation segment length) is more than 1.8m in the region, and is characterized in that the microwave transmitter output 0.1kW or 1.5kW less.

  Hereinafter, the present invention will be described in detail.

  FIG. 2 shows an example in which the conductive rubber roller according to the present invention is used in an electrophotographic apparatus.

  The electrophotographic apparatus shown in FIG. 2 is an electrophotographic laser printer using a process cartridge, and FIG. 2 is a diagram showing a schematic configuration thereof.

  The electrophotographic apparatus includes a drum-type electrophotographic photosensitive member (hereinafter referred to as “photosensitive drum”) 1 as an image carrier. In the photosensitive drum 1, a photosensitive layer made of an organic photoconductor (OPC) is provided on the outer peripheral surface of a grounded cylindrical aluminum substrate. The photosensitive drum 1 is rotationally driven by a driving means (not shown) at a predetermined process speed (circumferential speed), for example, 50 mm / sec, in the direction of arrow R1.

  The surface of the photosensitive drum 1 is uniformly charged by a charging roller 2 that is a contact charging member. The charging roller 2 is disposed in contact with the photosensitive drum 1 and is driven to rotate in the direction of arrow R2 as the photosensitive drum 1 rotates in the direction of arrow R1. An oscillation voltage (AC voltage VAC + DC voltage VDC) is applied to the charging roller 2 by a charging bias application power source (high voltage power source), whereby the surface of the photosensitive drum 1 is uniformly charged to −600 V (dark portion potential Vd). It is processed. The surface of the photosensitive drum 1 after charging is scanned and exposed by laser light 3 output from a laser scanner and reflected by a mirror, that is, laser light modulated in accordance with a time-series electric digital image signal of target image information. Receive. As a result, an electrostatic latent image corresponding to the target image information (bright part Vl = −150 V) is formed on the surface of the photosensitive drum 1.

  The electrostatic latent image is reversely developed as a toner image with negatively charged toner attached thereto by a developing bias applied to the developing sleeve of the developing device 4.

  On the other hand, a transfer material 7 such as paper fed from a paper supply unit (not shown) is guided by a transfer guide, and is transferred to a transfer unit (transfer nip unit) T between the photosensitive drum 1 and the transfer roller 6. The toner image is supplied in synchronism with the toner image on the photosensitive drum 1. The toner image on the photosensitive drum 1 is transferred to the surface of the transfer material 7 supplied to the transfer portion T by a transfer bias applied to the transfer roller 6 by a transfer bias application power source. At this time, the toner (residual toner) that is not transferred to the transfer material 7 and remains on the surface of the photosensitive drum 1 is removed by the cleaning device 9.

  The transfer material 7 that has passed through the transfer portion T is separated from the photosensitive drum 1 and introduced into the fixing device 10, where the toner image is fixed, and an electrophotographic apparatus main body (not shown) is formed as an image formed product (print). It is discharged outside.

  Here, the conductive rubber roller manufactured by the manufacturing method of the present invention is provided with a surface layer if necessary, and is used as the charging roller 2, the developing sleeve, the transfer roller 6, or the like. In particular, it is useful as a transfer roller.

(Manufacture of conductive rubber roller)
As the rubber component of the foam rubber layer of the present invention, epichlorohydrin rubber in which allyl glycidyl ether is copolymerized is used. The epichlorohydrin rubber is preferably an epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer.

  In the present invention, the rubber component is blended with dipentamethylene thiuram tetrasulfide, thiuram disulfide compound and morpholinodithio compound at least as a chemical foaming agent and a vulcanizing agent to obtain a raw rubber composition for a foam rubber layer. . The content of sulfur, which is usually a vulcanizing agent for epichlorohydrin rubber, is minimized.

  In the present invention, 1 part by mass or more and 3 parts by mass or less of dipentamethylene thiuram tetrasulfide which is a vulcanizing agent, 1 part by mass or more and 3 parts by mass or less of thiuram disulfide compound and morpholinodithio compound with respect to 100 parts by mass of the rubber component. 0.5 parts by mass or more and 1.5 parts by mass or less are contained, and sulfur is 0.2 parts by mass or less. The reason for this is that dipentamethylene thiuram tetrasulfide, thiuram disulfide compounds and morpholinodithio compounds used as vulcanizing agents decompose by heating to generate sulfide radicals, and these radical sulfurs undergo monosulfide crosslinking and set properties. This is because it improves. This is because if the sulfur content is more than 0.2 parts by mass, the ratio of monosulfide crosslinking is lowered and the setting property is lowered, which is not preferable. In addition, in this invention, the case where content of sulfur is 0 mass part shall be included.

In the present invention, any chemical foaming agent can be used as long as it is used in the production of foamed rubber. Among them, azodicarbonamide and p, p are preferred in view of ease of foaming and uniformity of foamed cells. '-Oxybisbenzenesulfonyl hydrazide is preferred. A foaming aid such as urea may be used. The amount of the chemical foaming agent used is suitably 1 to 10 parts by mass with respect to 100 parts by mass of the rubber component.

  In the present invention, a conductive material such as carbon black, a filler such as calcium carbonate, and other auxiliary agents may be mixed and used.

  After the rubber composition mixed with the raw materials as described above is extruded from the extruder, the output of the microwave transmitter is adjusted between 0.1 kW and 1.5 kW, and the irradiation section length is 1.8 m. Microwave foam vulcanization is performed in a microwave irradiation device that is between 2.0 m. The microwave irradiation amount is preferably 0.2 kW or more and 3.0 kW or less. For this reason, it is preferable to use two microwave transmitters, and the microwave transmitters are appropriately arranged so that the length of the microwave irradiation section is 1.8 m to 2.0 m.

  FIG. 3 shows a microwave continuous vulcanization manufacturing apparatus suitable for manufacturing a conductive rubber roller.

  In FIG. 3, 11 is an extruder, 12 is a microwave irradiation apparatus (UHF), 13 is a hot-air vulcanizer (HAV), 14 is a take-up machine, and 15 is a regular cutting machine.

  The rubber composition is kneaded using a closed kneader such as a Banbury mixer or a kneader, then formed into a ribbon shape using an open roll and a ribbon forming / dispensing machine, and then charged into the extruder 11. The rubber composition extruded into a tube shape from the extruder 11 is conveyed to the UHF 12 by a mesh-like belt coated with a fluororesin or a fluororesin-coated roller, and foamed and vulcanized. The rubber composition vulcanized with UHF 12 is conveyed to HAV 13 with a fluororesin-coated roller, and the foam vulcanization is completed. The UHF 12 and the HAV 13 are connected by a fluororesin-coated roller.

  In addition, the length of UHF12, HAV13, and the take-up machine 14 can be 4m, 6m, 1m in order, for example. Further, the distance between the UHF 12 and the HAV 13 and the distance between the HAV 13 and the take-up machine 14 are usually 0.1 m or more and 1.0 m or less. With such a configuration, the distance from the UHF to the take-up machine can be as extremely short as about 13 m.

  In the manufacturing apparatus using the microwave, the rubber composition extruded into a tube shape from the extruder 11 is conveyed into the UHF 12 immediately after being extruded, and is 100 ° C. or higher and 250 ° C. between 1.5 min and 2.5 min. Heated so that the amount of gas generated when the temperature is raised below 2.0 ° C. is 2.0 ml / g or more and 20.0 ml / g or less, vulcanized and foamed, and then sent to HAV 13 to complete the vulcanization. The

  In the UHF 12, it is preferable that the microwave irradiation section length is 1.8 m to 2.0 m and the irradiation intensity is 0.2 kW to 3.0 kW in total. Furthermore, it is preferable that the output of the microwave transmitter in the UHF 12 is 0.1 kW / unit or more and 1.5 kW / unit or less because microwaves are not excessively concentrated on the rubber composition. Further, the length of the microwave irradiation section is set to 1.8 m to 2.0 m in the microwave irradiation apparatus for foaming the rubber composition. For this purpose, it is preferable to use a plurality of microwave transmitters capable of adjusting the output from 0.1 kW to 1.5 kW, and adjust the output of each microwave transmitter within the above range to control the foam vulcanization.

  Immediately after being discharged from the take-up machine 14 after vulcanization and foaming, it is cut into a predetermined size by a regular cutting machine 15.

  To the cut foamed rubber tube, if necessary, after removing distortion, a hot melt adhesive or a vulcanized adhesive applied to a predetermined region is pressed into an inner diameter portion of a conductive core material of φ4 mm to 10 mm, A roller-shaped molded body is obtained. This molded body is set in a polishing machine (not shown) to which a polishing grindstone GC80 is attached, and polishing is performed so that the outer diameter is 17 mm, for example, at a rotational speed of 2000 rpm and a feed speed of 500 mm / min. create.

The conductive rubber roller manufactured in this way is, for example, as shown in the perspective view of FIG. In FIG. 1, 61 is a conductive core material, and a foam rubber layer 62 is formed around it. In the present invention, the surface of the foam rubber layer 62 may be further treated with energy rays such as ultraviolet rays and electron beams, and a functional surface layer may be formed on the surface. . Further, as the conductive rubber roller, it is desirable that the roller has a resistance value measured in an environment of 23 ° C. × 55% RH of 5 × 10 ⁵ Ω or more and 5 × 10 ⁹ Ω or less.

  The conductive rubber roller thus produced can be used as it is, or after surface treatment, as a roller for an electrophotographic apparatus.

  Hereinafter, the present invention will be described by way of examples.

  The materials used in the following examples and comparative examples are as follows.

1) Rubber component • CHR: Epichlorohydrin rubber “Hydrin T3106” (trade name), manufactured by Nippon Zeon Co., Ltd., epichlorohydrin-based terpolymer of epichlorohydrin-ethylene oxide-allyl glycidyl ether

2) Chemical blowing agent • OBSH: p, p′-oxybisbenzenesulfonylhydrazide “Neocerbon N” (trade name), manufactured by Eiwa Kasei Kogyo Co., Ltd. • ADAC: Azodicarbonamide “Vinihol AC” (trade name), Eiwa Kasei Made by Kogyo Co., Ltd.

3) Vulcanizing agent (vulcanization accelerator)
・ TPTT: Dipentamethylene thiuram tetrasulfide “Noxeller TRA” (trade name), manufactured by Ouchi Shinsei Chemical Co., Ltd. ・ TETD: Tetraethyl thiuram disulfide “Noxeller TET-G” (trade name), Ouchi Shinsei Chemical Co., Ltd. Manufactured by Thiuram disulfide compound MDB: 2- (4-morpholinodithio) benzothiazole “Noxeller MDB” (trade name), manufactured by Ouchi Shinsei Chemical Co., Ltd. Morpholinodithio compound DTDM: 4,4′-dithiodimorpholine “Barnock R” (trade name), manufactured by Ouchi Shinsei Chemical Industry Co., Ltd., morpholinodithio compounds / MBTS: Dibenzothiazyl disulfide “Noxeller DM” (trade name), manufactured by Ouchi Shinsei Chemical Industries Co., Ltd., other compounds / DPG : 1,3-diphenylguanidine "Noxeller D" (product) Name), manufactured by Ouchi Shinsei Chemical Co., Ltd., other compounds / TTCA: 2,4,6-trimercaptotriazine “Disnet F” (trade name), manufactured by Sankyo Kasei Co., Ltd., other compounds / sulfur: sulfur “Sulfax” PMC "(trade name), manufactured by Tsurumi Chemical Co., Ltd.

  Measurement methods and evaluation methods for various data in Examples and Comparative Examples are shown below.

(Aspect ratio measurement method for tube inner and outer diameters)
The foamed rubber tube is cut at an arbitrary location, and the cross section is cut with a projector “Nikon Profile Projector V-12B” (trade name, manufactured by Nikon Corporation), with the maximum (a) and minimum (b) ) Was measured. The ratio was calculated from the obtained measured values and used as the aspect ratio. At this time, it is preferable that a / b is closer to 1.

(Measurement method of unevenness of roller hardness)
Using a rubber hardness meter “Asker rubber hardness meter C type” (trade name, manufactured by Kobunshi Keiki Co., Ltd.), four locations of Asker C hardness were measured every 90 ° in the circumferential direction at any place on the conductive rubber roller. . The difference between the maximum value and the minimum value was expressed as roller hardness unevenness. This value is preferably 0 °.

(Measurement method for uneven electrical resistance of rollers)
A load of 4.9 N on one side is applied to both of the core material of the conductive rubber roller left for 48 hours in an N / N (23 ° C. × 55% RH) environment, and it is pressure-bonded to an aluminum drum having an outer diameter of 30 mm. In the rotated state, a voltage of 2 kV was applied between the core material and the aluminum drum, and the resistance value was measured. The logarithm of the ratio between the maximum value and the minimum value of the resistance value at this time was defined as resistance unevenness. The resistance unevenness is preferably less than 1.2.

(Confirmation method of cell diameter distribution)
Cut the foam rubber tube at an arbitrary location, and observe the cell diameter with a video microscope "Digital Microscope VH-8000" (trade name, manufactured by Keyence Corporation). The difference in the cell diameter on the side was confirmed. The state was evaluated according to the following criteria. It is preferable that there is no difference between the cell diameter on the outer diameter side and the cell diameter on the inner diameter side.
○: Almost no difference Δ: Slight difference is observed ×: Clear difference is observed

(C set property)
A conductive rubber roller is incorporated as a transfer roller into a laser printer “LBP-1310” (trade name) manufactured by Canon Inc. and placed in 23 ° C. × 55% RH (N / N environment) for one week, and then halftone images are continuously displayed. 30 sheets were output. The obtained halftone image was visually observed and C set property was evaluated according to the following criteria. In addition, evaluation A and B were considered that C set property was favorable.
A: There was no white streak of contact marks.
B: There are white streaks in the initial stage, but they disappeared on the way.
C: The white streak did not disappear until the end.

  In the following Examples and Comparative Examples, foam vulcanization was performed as follows unless otherwise specified. That is, the manufacturing apparatus shown in FIG. 3 was used. The total length excluding the extruder 11 is about 13 m, the UHF 12 is 4 m, the HAV 13 is 6 m, and the take-up machine 14 is 1 m. And between each apparatus can be adjusted between 0.1 m and 1 m, and the regular cutting machine 15 is provided in contact with the take-up machine 14. Between the extruder 11 and the UHF 12, the rubber composition extruded in a cylindrical shape from the extruder 11 is received by a mesh belt covered with a fluororesin and sent into the UHF 12. Further, a roller whose surface is coated with a fluororesin is provided between the UHF 12 and the HAV 13, and the rubber composition vulcanized and foamed in the UHF 12 is conveyed on the roller. Here, the UHF 12 has two microwave transmitters with a maximum output of 2.0 kW, and the irradiation section length is about 2 m (this can be appropriately changed by adjusting the position of the microwave transmitter). Yes. Also, heated air is fed into the HAV 13 and kept at 200 ° C.

Examples 1-5, Comparative Examples 1-5
100 parts by mass of CHR was used as a rubber component, and the vulcanizing agents shown in Tables 1 and 2 were added together with the foaming agent in the ratios shown in Tables 1 and 2 and kneaded with a Banbury mixer. Thereafter, it was molded into a ribbon shape using an open roll and a ribbon molding dispenser to obtain a rubber composition. Next, this rubber composition was put into an extruder 11 and extruded from the extruder 11 into a cylindrical shape so that the outer diameter after vulcanization and foaming was 20 mm and the inner diameter was 5 mm. Next, the cylindrical rubber composition was carried into UHF 12 in which the microwave transmitter was adjusted so that the microwave irradiation amount became 0.1 kW to 3.5 kW, and vulcanized and foamed. Subsequently, vulcanization foaming was completed in HAV13 adjusted to 200 ° C. to obtain a foamed rubber tube. Thereafter, the foamed rubber tube was taken up by the take-up machine 14 and cut into a length of 230 mm by the fixed length cutting machine 15.

  A conductive core material coated with a hot-melt adhesive was pressed into an iron rod having a surface of 6 mm outer diameter and 250 mm length and chemical nickel plating on the cut foam rubber tube. Then, it was placed at a temperature at which the hot melt adhesive was dissolved, and further cooled to room temperature to obtain a roller-shaped molded body. Both ends of the foam rubber layer of this molded body are cut off so that the length of the foam rubber layer is 220 mm, and then the surface is rotated with a grinding machine equipped with a grinding wheel GC80, the rotational speed of the workpiece is 400 rpm, Polishing was performed at a rotational speed of 2000 rpm and a feed speed of 500 mm / min to obtain a conductive rubber roller having an outer diameter of 17 mm.

In Examples 1-5 and Comparative Examples 1-5, the inner diameter of the produced foamed rubber tube, the aspect ratio of the outer diameter, the cell diameter distribution, and the obtained conductive rubber roller hardness unevenness, resistance value, resistance unevenness, C The set property was examined by the above. The results are shown in Tables 1 and 2.

  As seen in Examples 1 to 5, the aspect ratio of the inner and outer diameters of the tube is not limited to 1, and the cell diameter distribution is uniform. Furthermore, the hardness unevenness in the circumferential direction is small, and the resistance unevenness in the circumferential direction is 1.2 or less. On the other hand, in the comparative example, the aspect ratio of the inner and outer diameters of the tube, the cell diameter distribution, the hardness unevenness in the circumferential direction, and the resistance unevenness in the circumferential direction are all larger than in the example.

It is a perspective view of an example of a conductive rubber roller concerning the present invention. It is explanatory drawing of an example of the electrophotographic apparatus which concerns on this invention. It is explanatory drawing of an example of the manufacturing apparatus using the microwave which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Charging device 3 Exposure means 4 Developing device 5 Toner 6 Transfer roller 7 Recording medium 8 Cleaning blade 9 Waste toner container 10 Fixing device 11 Extruder 12 Microwave irradiation device (UHF)
13 Hot air vulcanizer (HAV)
14 Take-up machine 15 Standard cutting machine 61 Core material 62 Elastic layer

Claims (8)

In a method for producing a conductive rubber roller in which a foam rubber layer made of a rubber composition is formed on a conductive core material,
The rubber composition uses an epichlorohydrin rubber copolymerized with allyl glycidyl ether as a rubber component, and 1 part by mass or more and 3 parts by mass of dipentamethylene thiuram tetrasulfide as a vulcanizing agent with respect to 100 parts by mass of the rubber component. Hereinafter, it contains 1 part by mass or more and 3 parts by mass or less of a thiuram disulfide compound and 0.5 part by mass or more and 1.5 parts by mass or less of a morpholinodithio compound, the addition amount of sulfur is 0.2 part by mass or less, and further chemical foaming. Containing agents,
The rubber composition has a microwave transmitter output of 0.1 kW to 1.5 kW, and is irradiated with microwaves at an irradiation section length of 1.8 m to 2.0 m to form a foam. Method for producing a conductive rubber roller.   The method for producing a conductive rubber roller according to claim 1, wherein the microwave irradiation uses two microwave transmitters, and the microwave irradiation amount is 0.2 kW or more and 3.0 kW or less.   The method for producing a conductive rubber roller according to claim 1 or 2, wherein the chemical foaming agent is p, p'-oxybisbenzenesulfonylhydrazide or azodicarbonamide.   The method for producing a conductive rubber roller according to any one of claims 1 to 3, wherein the epichlorohydrin rubber is an epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer.   5. A roller for an electrophotographic apparatus, which is a conductive rubber roller formed by the method for manufacturing a conductive rubber roller according to claim 1. 6. The roller for an electrophotographic apparatus according to claim 5, wherein the resistance value is 5 × 10 ⁵ Ω or more and 5 × 10 ⁹ Ω or less in a 23 ° C. × 55% RH environment.   Furthermore, the surface layer is provided, The roller for electrophotographic apparatuses of Claim 5 or 6 characterized by the above-mentioned.   A transfer roller comprising the roller for an electrophotographic apparatus according to claim 5.

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