JP2006168171A - Manufacturing method of conductive rubber roller and conductive rubber roller for electrophotographic apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a conductive rubber roller uniform in the cell distribution of its foamed rubber layer and free from hardness and resistance irregularity, and the conductive rubber roller for an electrophotographic apparatus using the conductive rubber roller as a base layer member. <P>SOLUTION: The manufacturing method of the conductive rubber roller, which is constituted by providing the foamed rubber layer on a conductive core material, includs a process for molding a rubber composition tube from the rubber composition including an epichlohydrin rubber, an acrylonitrile/butandiene rubber or a mixture of them and a process for irradiating the rubber composition tube with a microwave with an irradiation output of 0.5-2.5 kW using a microwave irradiator wherein the length of a microwave irradiation region is 4 m or below while feeding the rubber composition tube through a microwave vulcanizer at a feed speed (a) of 0.5-3.0 m/min to heat the same so that a b/a value becomes 66-600(°C min/m) when the highest temperature of an article to be heated is set to b°C to raise the temperature thereof to foam/vulcanize the rubber composition tube to form a foamed rubber tube. <P>COPYRIGHT: (C)2006,JPO&NCIPI

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, or an electrostatic recording apparatus, and further to an electrophotographic image bearing member such as an electrophotographic photosensitive member (photosensitive drum). The present invention relates to a roller for an electrophotographic apparatus such as a transfer roller mounted on an image forming apparatus for transferring a transferable image formed by a toner image formed and supported by an image forming unit such as a process or an electrostatic recording process onto a transfer material such as paper.

  A conductive rubber roller such as a charging roller, a transfer roller, and a developing roller is used in many electrophotographic image forming apparatuses such as a copying machine and a printer. Conventionally, as a method for producing these conductive rubber rollers, a method of vulcanizing with a vulcanizer using high-pressure steam (for example, see Patent Document 1), a mold vulcanization with a cylindrical mold or the like (for example, see Patent Document 3) UHF vulcanization by microwave irradiation (for example, see Patent Document 2). These methods include, for example, a method of vulcanizing with a vulcanizing can, and a large amount of polishing must be performed in order to bring the desired cell to the surface because the cells of the resulting foamed foam of the roller are uneven. The vulcanization method by vulcanization is not suitable for making a large quantity because it takes time to set up and requires mold cleaning. In addition, the UHF vulcanization method provides good setup and uniform cells, but when the rubber is softened, the tube is crushed and the aspect ratio of the inner and outer diameters of the tube is not uniform. Further, the non-uniformity of the tube causes the circumferential hardness and resistance unevenness.

  Furthermore, in order to eliminate this non-uniformity of the tube, a method of connecting a plurality of short UHF devices and applying a gradient to the microwave irradiation output is known as a known technique, but it is a long device. In addition, the elapsed time becomes longer, microwaves are excessively applied, and the epichlorohydrin rubber and the acrylonitrile butadiene rubber, which are rubber materials, are altered, and the volume resistivity value of the rubber material is increased. For this reason, the above method is not suitable for conductive rubber rollers used in copiers, printers, etc., and introduces technology development for short diameter rollers that require fine performance such as resistance values. There was nothing to do.

  From this background, in the manufacturing method of conductive rubber rollers used in copiers, printers, etc., where the foam rubber layer cells are required to be uniform and have no circumferential hardness and resistance unevenness, the setup in the manufacturing process Manufacturing methods with good productivity and productivity are demanded.

JP 11-114978 A JP-A-11-201140 Japanese Patent Laid-Open No. 2002-221859

  Accordingly, the present invention relates to a conductive rubber roller for an electrophotographic apparatus such as a transfer roller, a charging roller or a developing roller having a foam rubber layer, and the rubber composition tube is heated and heated by microwave irradiation from a short distance. The present invention provides a method for producing a conductive rubber roller and a roller for an electrophotographic apparatus that are vulcanized and foamed, have a small aspect ratio of inner and outer diameters, a uniform cell distribution, and have no circumferential hardness unevenness and resistance unevenness. For the purpose.

The method for producing a conductive rubber roller of the present invention that has solved the above problems is a method for producing a conductive rubber roller having a foamed rubber layer on a conductive core material, and a rubber containing epichlorohydrin rubber, acrylonitrile butadiene rubber, or a mixture thereof. A step of molding a rubber composition tube from the composition and an area in which microwaves are irradiated while the rubber composition tube is conveyed at a conveyance speed a of 0.5 to 3.0 m / min in the microwave vulcanizing apparatus. Using a microwave irradiation apparatus with a length of 4 m or less, irradiating microwaves with an irradiation power of 0.5 to 2.5 KW, and the maximum temperature of the heated object at this time is b ° C, the value of b / a Characterized in that it comprises a step of heating to a temperature of 66 to 600 ° C. · min / m and foaming and vulcanizing the rubber composition tube to form a foamed rubber tube. .
Moreover, the roller for an electrophotographic apparatus of the present invention that has solved the above-described problems is characterized in that a conductive rubber roller manufactured by the method for manufacturing a conductive rubber roller of the present invention is used as a base layer member.

  As described above, in a method for producing a conductive rubber roller having a foam rubber layer on a conductive core material, a rubber composition tube is formed from a rubber composition containing epichlorohydrin rubber, acrylonitrile butadiene rubber, or a mixture thereof. Microwave irradiation apparatus in which the length of the area to be irradiated with microwaves is 4 m or less while the rubber composition tube is conveyed at a conveyance speed a of 0.5 to 3.0 m / min in the process and the microwave vulcanizing apparatus When the maximum temperature of the object to be heated at this time is b ° C., the value of b / a is 66 to 600 ° C./min/m. The method of manufacturing a conductive rubber roller, comprising heating and heating so as to form a foamed rubber tube by foaming and vulcanizing the rubber composition tube, Foam rubber to reduce the aspect ratio of the inner and outer diameters of the tube, and a cell distribution uniform, circumferential direction of the uneven hardness, it is possible to provide a no conductive rubber roller resistance unevenness.

  Moreover, the roller manufactured using the conductive rubber roller manufactured by the manufacturing method of the said conductive rubber roller as a base layer member can be used conveniently as a roller for electrophotographic apparatuses, especially as a transfer roller.

  The present invention relates to a process for forming a rubber composition tube from a rubber composition containing epichlorohydrin rubber, acrylonitrile butadiene rubber, or a mixture thereof in a method for producing a conductive rubber roller having a foamed rubber layer on a conductive core. Using the microwave irradiation apparatus having a length of the area irradiated with microwaves of 4 m or less while conveying the rubber composition tube at a conveying speed a of 0.5 to 3.0 m / min in the wave vulcanizing apparatus, When microwaves with an irradiation power of 0.5 to 2.5 KW are irradiated and the maximum temperature of the heated object at this time is b ° C., the value of b / a is 66 to 600 ° C./min/m. A method for producing a conductive rubber roller, comprising heating and heating to foam and vulcanize the rubber composition tube to form a foamed rubber tube.

Hereinafter, the present invention will be described in detail.
(Description of the relationship between the conductive rubber roller of the present invention and the image forming apparatus)
FIG. 2 shows an example of an image forming apparatus provided with the conductive rubber roller or the electrophotographic apparatus roller according to the present invention. The image forming apparatus shown in the figure is an electrophotographic laser printer using a process cartridge, and the figure is a longitudinal sectional view showing a schematic configuration thereof. In addition, the conductive rubber roller or the electrophotographic apparatus roller of the present invention is mounted as the charging roller 2, the transfer roller 6, or the developing roller 30 in the image forming apparatus shown in FIG.

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

  The surface of the photosensitive drum 1 is uniformly charged by a charging roller 2 as a contact charging member. The charging roller 2 is disposed in contact with the surface of 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 oscillating 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). Is done. The surface of the photosensitive drum 1 after charging is subjected to scanning exposure 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 by attaching negatively charged toner by a developing bias applied to the developing roller 30 of the developing device 4.

  On the other hand, a transfer material 7 such as paper fed and fed from a paper feed unit (not shown) is guided by a transfer guide to a transfer unit (transfer nip unit) T between the photosensitive drum 1 and the transfer roller 6. The toner image on the photosensitive drum 1 is supplied so as to match the timing. 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 (not shown). At this time, the toner (residual toner) not transferred to the transfer material 7 but remaining on the surface of the photosensitive drum 1 is removed by the cleaning device 9.

  The material 7 to be transferred 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 subjected to fixing processing, and is discharged outside the image forming apparatus main body as an image formed product (print). Is done.

(Explanation regarding the manufacturing method of conductive rubber roller)
In FIG. 1, the sketch of the conductive rubber roller of one Embodiment of this invention is shown.
The conductive rubber roller of the present invention has a foamed rubber layer 62 on a conductive core 61. As the conductive core 61, a round bar made of a metal material such as iron, copper, and stainless steel having an outer diameter φ of preferably 4 to 10 mm can be used. Furthermore, these surfaces may be plated for the purpose of providing rust prevention and scratch resistance.

  The rubber composition, which is a raw material for forming the foam rubber layer 62 in the present invention, includes epichlorohydrin rubber, acrylonitrile butadiene rubber, or a mixture thereof. If desired, an azodicarbonamide-based foaming agent, sulfur, organic Vulcanizing agents such as peroxides, triazines, polyamines, thiuram, thiazole, guanidine, sulfenamide, dithiocarbamate, thiourea vulcanization accelerators, conductive agents such as carbon black, calcium carbonate, etc. Including other fillers and other auxiliaries. As epichlorohydrin rubber, for example, Zeklon 3106 (trade name) manufactured by Nippon Zeon Co., Ltd. is used, and as acrylonitrile butadiene rubber, for example, DN401 (trade name) manufactured by Nippon Zeon Co., Ltd. is used as an azodicarbonamide type. As the foaming agent, for example, VINYHALL AC (trade name) manufactured by Eiwa Chemical Industry Co., Ltd. can be preferably used.

  The method for preparing the rubber composition from each of the above components is not particularly limited. For example, a suitable one may be selected from known methods according to the raw materials, composition, and the like to be used. Specifically, for example, predetermined components such as a rubber component, a foaming agent, a conductive agent, a vulcanizing agent, and a vulcanization accelerator are kneaded using a closed kneader such as a Banbury mixer or a kneader, for example. What is necessary is just to prepare a thing.

  FIG. 3 shows an example of a vulcanization molding apparatus that can be used in the present invention. This apparatus includes an extruder 11, a microwave vulcanizer (sometimes referred to as a UHF vulcanizer) 12 as a temperature raising heating means, and a hot air vulcanizer (HAV vulcanization) as a hot air heating means if desired. (It may be expressed as an apparatus) 13, a wind take-up machine 14, and a regular cutting machine 15.

  For example, the rubber composition prepared by kneading with a closed kneader such as a Banbury mixer or a kneader described above is formed into a ribbon shape with an open roll and a ribbon forming dispenser (not shown), and then the extruder 11. It is thrown into. The UHF vulcanizer 12 includes a mesh belt coated with Teflon or a roller coated with Teflon resin, and an unvulcanized rubber composition tube extruded by the extruder 11 is conveyed thereon. While being conveyed, microwaves are irradiated, heated and heated, foamed, vulcanized (may be referred to as “foamed / vulcanized”), and a foamed rubber tube is formed. This foamed rubber tube is conveyed to the HAV vulcanizer 13 if desired. The UHF vulcanizer 12 and the HAV vulcanizer 13 are connected by a roller coated with Teflon resin. The HAV vulcanizing device 13 is provided with a roller coated with Teflon resin, and the foamed rubber tube is transported over this and exposed to hot air while being transported to be further vulcanized. The foamed rubber tube is taken up by the winder 14, and immediately after being discharged from the winder 14, the foamed rubber tube is cut into a desired dimension by the fixed length cutter 15 to prepare a foamed rubber tube molding having conductivity. .

  In the present embodiment, the lengths of the UHF vulcanizer 12, the HAV vulcanizer 13, and the winder 14 are 4 m, 6 m, and 1 m in this order. The gaps between the UHF vulcanizer 12 and the HAV vulcanizer 13 and between the HAV vulcanizer 13 and the winder 14 are set to be 0.1 to 1.0 m.

  In the vulcanization molding apparatus, the unvulcanized rubber composition tube formed by extruding the rubber composition into a tube shape by the extruder 11 is placed in the UHF vulcanization apparatus 12 immediately after being extruded from the extruder 11. It is conveyed and conveyed in the UHF vulcanizer at a conveying speed a of 0.5 to 3.0 m / min. In the UHF vulcanizer 12, a microwave irradiation device having a length of a microwave irradiation area of 4 m or less is used to irradiate microwaves with an irradiation power of 0.5 to 2.5 KW, and the object to be heated at this time When the maximum temperature is b ° C., the rubber composition tube is foamed and vulcanized by heating and heating so that the value of b / a is 66 to 600 ° C./min/m. Form.

  The conveyance speed a is preferably 0.5 to 3.0 m / min, and more preferably 1.0 to 3.0 m / min. When the conveyance speed a is 0.5 m / min or more, a more stable vulcanized state is obtained, and when the conveyance speed a is 3.0 m / min or less, a more stable foaming state is obtained.

  Further, the length of the area irradiated with the microwave is preferably 4 m or less, and more preferably 3 m or less. When the length of the area irradiated with microwaves is 4 m or less, a uniform and stable foamed state can be obtained.

  The microwave is irradiated with an output of 0.5 to 2.5 KW. The microwave irradiation output is preferably 0.5 to 2.5 kW, and more preferably 0.5 to 1.5 kW. When the microwave irradiation output is 0.5 KW or more, sufficient irradiation can be performed even in a short apparatus configuration. On the other hand, when it is 2.5 KW or less, excessive heating can be easily avoided, and control is very easy even when a fine short-diameter conductive rubber roller is manufactured.

  Further, it is preferable to heat up and heat so that the value of b / a is 66 to 600 ° C. · min / m, and it is more preferable to heat up and heat so that this value is 66 to 200 ° C. · min / m. preferable. The maximum temperature b ° C. of the article to be heated is usually preferably 150 to 300 ° C.

  If desired, subsequently, the foamed rubber tube is conveyed to the HAV vulcanizer 13 and heated in a hot air furnace of the HAV vulcanizer 13 while conveying the foamed rubber tube to complete the vulcanization. The heating conditions in the hot air furnace of the HAV vulcanizer 13 are not particularly limited, but it is usually preferable to carry out hot air heating at 150 to 300 ° C. for 4 to 10 minutes. The hot air furnace of the HAV vulcanizer 13 is preferably a hot air furnace using a gas furnace as a heat source. If a gas furnace is used as a heat source, a uniform heating state can be obtained by a small amount of water vapor generated during gas combustion.

  The foamed rubber tube obtained by completing the vulcanization is taken up by a winder 14, and immediately after being discharged from the winder 14, the foamed rubber tube is cut to a desired size by a fixed length cutter 15 to have a conductive foam. A rubber tube molding is prepared.

  Next, a conductive core material in which an adhesive such as a hot melt adhesive or a vulcanized adhesive is applied to a desired region is press-fitted into the inner diameter portion of the foamed rubber tube molding, and a foamed rubber tube is formed on the conductive core material. A roller-like molded body is obtained by bonding the product to form a foamed rubber layer. This roller-shaped molded body is set in a polishing machine (not shown) and polished under predetermined polishing conditions to produce a conductive rubber roller having a predetermined outer diameter.

  Furthermore, using the obtained conductive rubber roller as a base layer member, a roller for an electrophotographic apparatus such as a charging roller, a developing roller, or a transfer roller can be obtained.

  For example, the developing roller and the charging roller are a bleed-out preventing layer that prevents bleeding from the foamed rubber layer on the outer peripheral surface of the foamed rubber layer of the conductive rubber roller, an electrode layer, and a resistance control layer that controls electrical characteristics. In addition, a layer for imparting a desired function such as a coating layer provided so as not to give scratches or contamination to the photosensitive drum or the like may be provided as necessary. As a method for providing the exudation preventing layer, the electrode layer, the resistance control layer, the coating layer, and the like, a known method, for example, a method using a coating solution such as a dip coating method or a roll coating method, a simultaneous forming multilayer seamless Examples include a method of covering the tube.

  In addition, for example, the transfer roller has a bleed-out preventing layer that prevents bleeding from the foamed rubber layer on the outer peripheral surface of the foamed rubber layer of the conductive rubber roller, a resistance control layer that controls electrical characteristics, and a material to be transferred. A layer for imparting a desired function, such as a surface texture control layer for controlling the surface texture in order to improve the transportability, may be provided as necessary. These layers can be formed by the same method as in the case of the developing roller or the charging roller. Moreover, when it has desired performance, you may use the said conductive rubber roller as it is as a transfer roller.

  Next, the present invention will be described in detail based on examples.

(Examples 1-5, Comparative Examples 1-5)
A conductive rubber roller (FIG. 1) demonstrating the present invention was prepared as follows.
Acrylonitrile butadiene rubber (manufactured by Nippon Zeon Co., Ltd., DN401; trade name) 75 parts by mass, epichlorohydrin rubber (manufactured by Nippon Zeon Co., Ltd., Zecron 3106; trade name), 25 parts by mass, azodicarbonamide (Yewa Kasei Kogyo Co., Ltd.) Co., Ltd., VINYHALL AC; trade name: 4 parts by mass, stearic acid (manufactured by Kao Corporation, LUNAC S20; trade name), 1 part by mass, zinc oxide (manufactured by Hakusui Chemical Co., Ltd., Zinc Hana No. 1) Product name) 5 parts by mass, carbon (Asahi Carbon Co., Ltd., Asahi 35; product name) 10 parts by mass are kneaded with a Banbury mixer, and formed into a ribbon shape using an open roll and a ribbon molding dispenser. The rubber composition molded into a ribbon shape was put into an extruder 11 (manufactured by Micro Electronics Co., Ltd.) of the vulcanization molding apparatus shown in FIG.
An unvulcanized rubber composition tube was extruded.

The rubber composition tube was heated and heated under the conditions shown in Tables 1 and 2 with a UHF vulcanizer 12 (manufactured by Micro Electronics Co., Ltd.) (length of the area irradiated with microwaves: 4 m), Foaming and vulcanization were performed, and the resulting foamed tube was taken up by a winder 14 and cut by a regular cutter 14 to obtain a foamed rubber tube molded product having an outer diameter φ16.0 mm, an inner diameter φ5.0 mm, and a length of 250 mm. . Next, E3315 (Three Bond Co., Ltd.)
Co., Ltd .; product name) applied to a desired region with an outer diameter φ 6.0 mm conductive core material pressed into the inner diameter of the foam rubber tube molding, and the foam rubber tube molding is bonded to the conductive core material, A roller-like molded body having a foamed rubber tube molding as a foamed rubber layer was obtained. This roller-shaped compact is set in a polishing machine (not shown) equipped with a polishing grindstone GC80, and polished to have an outer diameter of 17 mm at a rotational speed of 2000 rpm and a feed speed of 500 m / min. A rubber roller was produced.

  Temperature measurement of rubber composition tube during microwave irradiation in the above examples and comparative examples, measurement of inner and outer diameter aspect ratio of foamed rubber tube molding, evaluation of cell diameter distribution of foamed rubber tube molding, hardness of conductive rubber roller The unevenness measurement and the electrical resistance unevenness measurement of the conductive rubber roller were performed as follows. The obtained results are shown in Tables 1 and 2.

(Method of measuring the temperature of the rubber composition tube during microwave irradiation)
Using a fluorescence thermometer (Anritsu Co., Ltd., fluorescent optical fiber thermometer FL-2000; trade name), the detection unit of the fluorescence thermometer was inserted into the rubber composition tube extruded from the extruder 11, and UHF was added. The rubber composition tube is conveyed together with the unvulcanized rubber composition tube into the vulcanizing apparatus 12 and heated at a temperature by microwave irradiation to measure the temperature when the rubber composition tube is foamed and vulcanized to form a foamed rubber tube.

(Measurement method of inside / outside diameter aspect ratio of foamed rubber tube molding)
The foamed rubber tube molded product is cut at an arbitrary location under an arbitrary condition, and the cross section thereof is projected with a projector (Nikon Corporation, Profile Projector V-12B; trade name), and the maximum portion of each inner and outer diameter (t _max ) And the minimum part (t _min ), and the ratio (t _max / t _min ) is determined. At this time, this ratio is preferably closer to 1.

(Measurement method for uneven hardness of conductive rubber roller)
Using a hardness tester (Asker C type, 4.9N load), measure any location of the foamed rubber layer of the conductive rubber roller at 90 ° intervals in the circumferential direction and determine the difference between the maximum and minimum values. It was uneven. The hardness unevenness is preferably close to zero.

(Measurement method of electrical resistance unevenness of conductive rubber roller)
After leaving in an environment of 23 ° C x 55% RH for 48 hours, both ends of the shaft of the conductive rubber roller are each loaded with a load of 4.9 N and pressed onto an aluminum drum with an outer diameter of 30 mm and rotated. In this state, a voltage of 2 kV was applied between the conductive core material of the conductive rubber roller and the aluminum drum. The difference (R _max −R _min ) between the maximum value R _max and the minimum value R _min of the resistance value at this time is represented by a digit. The electrical resistance unevenness is preferably less than 1.2 digits.

(Method for evaluating cell diameter distribution of foamed rubber tube molding)
Cut the foamed rubber tube molding at an arbitrary location, and record the cross section with Video Micro (Keyence, Digital Microscope VH-8000; trade name). The difference in size was measured with a measure. At this time, it is preferable that there is no difference between the cell diameter (D _ou ) on the outer diameter side and the cell diameter (D _in ) on the inner diameter side, and the cell diameter distribution was evaluated according to the following criteria based on the obtained results.
○ No difference [(│D _ou -D _in │ / D _ou ) ≦ 1.5 or (| D _ou −D _in │ / D _in ) ≦ 1.5)]
△ There is a slight difference [(1.5 <(│D _ou -D _in │ / D _ou ) ≦ 2.0 or 1.5 <(| D _ou −D _in │ / D _in ) ≦ 2.0)]
× There is a difference [(│D _ou -D _in │ / D _ou ) > 2.0 or (│D _ou -D _in │ / D _in )> 2.0)]

  As shown in Table 1, in Examples 1 to 5, the ratio b / a between the conveyance speed a (m / min) in the microwave vulcanizer and the maximum temperature b ° C. of the object to be heated is 66. It can be seen that the ratio of the inner and outer diameters of the foamed rubber tube molded product is as small as 1.02 or less and the cell diameter distribution is uniform. Further, it can be seen that the hardness unevenness in the circumferential direction of the conductive rubber roller is small and the resistance unevenness is as small as 1.07 digits or less.

  On the other hand, in Comparative Examples 1-5, as shown in Table 2, the case where microwave irradiation output 0.3kW, 3.0kW, conveyance speed 0.3m / min, 3.5m / min was mentioned. It was. In Comparative Examples 2 and 4, the aspect ratio of the inner and outer diameters of the foamed rubber tube molding, the cell diameter distribution, the hardness irregularity and the resistance irregularity of the conductive rubber roller were not vulcanized and foamed, and could not be measured or measured. Even in this case, the aspect ratio of the inner and outer diameters of the foamed rubber tube molded product is as large as 2.1 to 3.3, the cell diameter distribution is large, the hardness unevenness in the circumferential direction, and the resistance unevenness in the circumferential direction are from the examples. It is clear that

  The conductive rubber roller and the electrophotographic apparatus roller obtained by the production method of the present invention can be suitably used as a transfer roller or the like in an image forming apparatus such as an electrophotographic copying apparatus, a printer, or an electrostatic recording apparatus.

It is a sketch of the conductive rubber roller of one embodiment of the present invention. 1 is a schematic cross-sectional view of an example of an image forming apparatus provided with a conductive rubber roller or an electrophotographic apparatus roller of the present invention. It is a section schematic diagram of an example of a vulcanization molding device in the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Photosensitive drum 2 Charging roller 3 Laser beam 4 Developing device 5 Toner 6 Transfer roller 7 Transfer material 8 Cleaning blade 9 Cleaning device 10 Fixing device 30 Developing roller 61 Conductive core material 62 Foam rubber layer 11 Extruder 12 Microwave vulcanization Equipment (UHF vulcanizer)
13 Hot-air vulcanizer (HAV vulcanizer)
14 Winding machine 15 Standard cutting machine

Claims (6)

  Process for forming a rubber composition tube from a rubber composition containing epichlorohydrin rubber, acrylonitrile butadiene rubber, or a mixture thereof in a method for producing a conductive rubber roller having a foam rubber layer on a conductive core, and a microwave vulcanizing apparatus While the rubber composition tube is being transported at a transport speed a of 0.5 to 3.0 m / min, a microwave irradiation device having a length of the area irradiated with microwaves of 4 m or less is used. 5 to 2.5 KW of microwaves is irradiated, and when the maximum temperature of the object to be heated is b ° C., the heating is performed so that the value of b / a is 66 to 600 ° C./min/m. A method for producing a conductive rubber roller, comprising the step of foaming and vulcanizing the rubber composition tube to form a foamed rubber tube.   2. The method for producing a conductive rubber roller according to claim 1, further comprising a step of heating the foamed rubber tube with hot air heating means at a temperature of 150 to 300 [deg.] C. for 4 to 10 minutes for further vulcanization.   The method for producing a conductive rubber roller according to claim 2, wherein the hot air heating means is a heating means using a gas furnace as a heat source.   The method for producing a conductive rubber roller according to claim 1, wherein the rubber composition contains azodicarbonamide.   A roller for an electrophotographic apparatus, wherein the conductive rubber roller manufactured by the method for manufacturing a conductive rubber roller according to claim 1 is used as a base layer member. The roller for an electrophotographic apparatus according to claim 5, wherein the roller for the electrophotographic apparatus is a transfer roller.

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