JP2007334229A - Elastic roller and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a roller manufacturing method capable of accomplishing uniform heating with accurate temperature distribution in a short time, and also, capable of manufacturing a roller with less difference in outside diameter and with uniform-shaped outside diameter. <P>SOLUTION: Regarding the elastic roller manufacturing method to form an unvulcanized rubber roller by using a core bar and covering the periphery of the core bar with unvulcanized rubber, thereafter, thermally hardening the unvulcanized rubber roller, the axial center of the core bar is arranged in a gravity direction, and a plurality of IR heaters are horizontally arranged in the shape of a side wall so as to be orthogonal to the unvulcanized roller, and the position of the IR heater as a unit is adjustable up and down, back and forth, and also, the position of the single heater is finely adjustable back and forth. The output can be individually set within an optional range of the heating temperature by a temperature setting machine. By such the primary vulcanizing method, the method of manufacturing the roller with less difference in outside diameter and with uniform-shaped outside diameter can be provided. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an elastic roller having an elastic layer around an axial core used in an electrophotographic apparatus or the like.

  First, an outline of the electrophotographic recording apparatus will be described. An image forming unit is installed inside the main body of the apparatus, and an image is formed through cleaning, charging, latent image, development, transfer, and fixing processes. The image forming unit includes a photosensitive drum as an image carrier, and includes a cleaning unit, a charging unit, a latent image forming unit, a developing unit, and a transfer unit. The image on the photosensitive drum formed by the image forming unit is transferred to a recording material by a transfer member, conveyed, and then heated and pressed by a fixing unit, and discharged as a fixed recorded image.

  Next, among the cleaning, charging, latent image, development, transfer, and fixing processes, the charging, latent image formation, development, and transfer processes will be described. The charging member performs a primary charging process on the surface of the photosensitive drum so that a predetermined polarity and potential are uniform. After being uniformly charged by the charging member, the target image information is exposed to form an electrostatic latent image corresponding to the target image on the surface of the photosensitive drum. The electrostatic latent image is visualized as a toner image by the developing device. The visualized toner image is transferred to the recording material by applying a voltage from the back surface of the recording material by a transfer unit under the photosensitive drum. Thereafter, the recording material is conveyed to a fixing unit, subjected to image fixing, and output as an image formed product.

  As a means for executing the developing process in the image forming apparatus such as the electrophotographic apparatus described above, a roller-type conductive elastic body that applies a developing action by applying a voltage has been actively used in recent years. The elastic layer of an elastic roller (charging roller, transfer roller, developing roller, etc.) used in an image forming apparatus utilizing such an electrophotographic process is formed using an elastic material such as liquid rubber, solid rubber, foam rubber, or the like. Yes.

  Next, a method for manufacturing the elastic roller will be described. Japanese Patent Application Laid-Open No. 2002-187157 introduces a method of performing primary molding vulcanization after crosshead extrusion and then secondary vulcanization in an oven. The following is a simple example. A rubber composition is extruded on the outer circumference of the metal shaft, and is extruded into a cylindrical shape on the outer circumference of the shaft by using a cross head type extruder to obtain an unfoamed (unvulcanized) rubber roller. This unfoamed (unvulcanized) rubber roller is set in a cylindrical split mold, pressure is applied, and vulcanized and foamed at 175 ° C. for 20 minutes. Next, the pressure of the split mold is released to obtain a foamed (primary vulcanized product) rubber roller. This rubber roller is post-vulcanized in an oven adjusted to 180 ° C. for 4 hours. After obtaining the conductive roller elastic body base layer by the above method, the outer shape is polished into a prescribed shape.

  In this state, it can be used as a member for an image forming apparatus such as an electrophotographic apparatus or an electrostatic recording apparatus. However, if necessary for the electrophotographic characteristics, a method such as dip coating may be used to form the elastic base layer. A conductive surface layer of several tens of μm is provided on the outer peripheral surface to complete an elastic roller for image formation.

  In addition, as a molding method that does not use a metal mold, a method of manufacturing an elastic roller (hereinafter, referred to as “coating”) in which a liquid resin is coated around a cylindrical core metal using a cylindrical coating head and then heat-cured and vulcanized , Called ring coating method). In this case, as for the vulcanization method of the roller after coating, the primary vulcanization and the secondary vulcanization are both heat-cured with a hot air circulation dryer at 200 ° C.

  Japanese Patent Laid-Open No. 2002-326235 introduces a method of horizontally conveying and heating the roller in the longitudinal direction in a furnace in which hot air of 180 ° C. is circulated. This method is effective in the case of foaming rubber compound raw material resin.

  Although the elastic roller manufacturing method has been described above, the outer diameter of the elastic roller is determined by the outer diameter error in the process of coating the liquid resin around the cylindrical cored bar, heat curing, and vulcanizing to obtain the elastic base layer. As for the accuracy of, when the fluctuation of the heating temperature distribution in the process of heat-curing and vulcanizing the elastic base layer is large, an outer diameter error occurs up to about 100 μm. Accordingly, it is important in the electrophotographic image forming apparatus to precisely adjust the heating temperature of the elastic roller to obtain the axial uniformity of the outer diameter with high accuracy.

When the elastic roller is a developing roller and the uniformity of the outer diameter is poor, charging characteristics (charge amount, etc.) to the toner supplied from the toner supply roller vary, and the supplied toner amount is stable. The problem of not doing may occur. For this reason, it becomes difficult to stably supply toner to the photosensitive drum. When the elastic roller is a charging roller and the outer diameter uniformity is poor, the pressure and contact area of the part in contact with the photosensitive drum is not uniform, and as a result, the resistance value of the contact part changes. Therefore, it becomes difficult to uniformly charge the surface of the photosensitive drum.
JP 2002-187157 A JP 2003-190870 A JP 2002-326235 A

  The above conventional example does not disclose a method for precisely adjusting the temperature distribution of heat acting on the roller during vulcanization. Accordingly, an object of the first invention according to the present application is to provide a method for manufacturing a roller by a precise heating method that can be used for primary vulcanization after extrusion molding and molding by ring coating.

  The object of the second invention according to the present application is to provide a production method capable of shortening the primary vulcanization time of the roller as compared with the conventional vulcanization method using a mold and the vulcanization method using a hot air circulation dryer (oven). It is to be.

In the manufacturing method of an elastic body roller, which is manufactured by coating an unvulcanized rubber around the core metal and forming an unvulcanized rubber roller by heating and curing the unvulcanized roller.
The core of the core bar is arranged in the direction of gravity, and a plurality of infrared heaters for heating are arranged in a side wall shape so as to be orthogonal to the unvulcanized roller in the horizontal direction. The heater can be finely adjusted in the front-rear direction with a single heater. Further, the output can be individually set within an arbitrary range of the heating temperature by a temperature setting machine. This primary vulcanization method can provide a roller manufacturing method having a uniform outer diameter with little difference in outer diameter.

  A heating part that irradiates the unvulcanized roller with infrared rays using an infrared heater to raise the temperature of the unvulcanized roller, and an infrared heater similar to the infrared heater is used to lower the output of the infrared heater and raise the unvulcanized roller. By using a method in which the unvulcanized roller is heated and cured and primary vulcanized using an infrared heater composed of a heat retaining portion that irradiates infrared rays so that the heated temperature can be maintained, the elastic roller can be moved in a short time. Can be heated.

  As described above, according to the present invention, in the manufacture of an elastic roller having an elastic body layer in which a liquid resin is vulcanized and cured on the outer peripheral surface of the shaft core body, infrared rays are emitted from the infrared heater to which the invention is devised. Uniform heating with a precise temperature distribution can be achieved in a short time by using a method of irradiating the unvulcanized roller and heat-curing and primary vulcanizing while rotating the unvulcanized roller. A roller manufacturing method having a uniform outer diameter with little difference can be provided.

  The present inventors formed an elastic body roller using a ring coating method in the elastic body layer forming step of the elastic body roller, and then sent infrared rays to the unvulcanized roller from the infrared heater which was devised as described above. It has been found that the above-mentioned problems can be solved by using a method of heat-curing and primary-curing while rotating the uncured roller while rotating the unvulcanized roller. The present invention has been made based on this finding.

[Ring coating machine]
FIG. 1 is a schematic view showing an example of a ring coating machine that can be suitably used in the present invention.

  As shown in FIG. 1, a column 2 is attached to the gantry 1 as a frame pillar substantially vertically, and a precision ball screw 3 is attached to the gantry 1 and the column 2 substantially vertically. Reference numeral 14 denotes a linear guide, two of which are attached to the column 2 in parallel with the precision ball screw 3.

  The LM guide 4 is connected to the linear guide 14 and the precision ball screw 3, so that the rotary motion is transmitted from the servo motor 5 through the pulley 6 so that the LM guide 4 can be moved up and down.

  In the column 2, a ring-shaped forming head 8 for discharging a material liquid for forming an elastic body layer is attached to the outer peripheral surface of a cylindrical shaft core body 101.

  Further, a bracket 7 is attached to the LM guide 4. A work lower holding shaft 9 for holding and fixing the roller shaft core body 101 is attached to the bracket 7 substantially vertically, and a center axis of the work upper holding shaft 10 for holding the roller shaft core body 101 on the opposite side is provided. It is attached to the upper part of the bracket 7 and the work upper holding shaft is arranged so as to be substantially concentric with the work lower holding shaft 9 so as to hold the shaft core. Further, the center axis of the ring-shaped coating head 8 is supported by each holding shaft so as to be parallel to the moving direction of the workpiece lower holding shaft 9 and the workpiece upper holding shaft 10. Further, when the workpiece lower holding shaft 9 and the workpiece upper holding shaft 10 are moved up and down, the center axis of the discharge port (205 in FIG. 2) formed in an annular slit opened inside the coating head 8 and the workpiece lower holding. The shaft 9 and the center axis of the workpiece holding shaft 10 are adjusted so as to be substantially concentric. With such a configuration, the central axis of the discharge port formed in the annular slit of the coating head 8 can be aligned with the central axis of the shaft core body so as to be substantially concentric with the inner peripheral surface of the ring-shaped coating head and the shaft. A uniform gap is formed between the outer peripheral surface of the core body 101.

  The material liquid supply port 11 is connected to a material supply valve 13 via a material liquid transport pipe 12. The material supply valve 13 includes a mixing mixer, a material supply pump, a material fixed amount discharge device, a material tank, and the like in front of the material supply valve 13 so as to discharge a fixed amount (a constant amount per unit time).

[Coating head]
FIG. 2 shows a cross section of an example of a ring-shaped coating head that can be used in the manufacturing method of the present invention. The ring-shaped coating head is composed of a head upper part 201 and a head lower part 202 formed of a material such as metal, and these are fixed to each other as shown in FIG. The raw material entered from the material injection port 203 is filled in the direction of 360 degrees through the material flow path 204 in the head, and is discharged from the material discharge port 205.

[Infrared heating device]
Next, an infrared heating apparatus that performs heating for primary vulcanization will be described. An infrared heating device using a halogen lamp as a heating light source was prepared. FIG. 7 is a schematic diagram for explaining an example of a heating apparatus that can be used in the present invention. As shown in FIG. 8, the heating light source was composed of two units, a roller temperature raising unit and a temperature holding unit. In the following, description will be given with reference to FIGS. The heaters 301 of each unit are 14 200V1000W types manufactured by Iwasaki Electric Co., Ltd., and are arranged in a side wall shape at a heater pitch = 20 mm so as to be orthogonal to the roller of the object to be heated. The heater heating effective range was 600 mm in the horizontal direction. With the temperature setting machine, the heating temperature can be set individually for any output (heater capacity x percentage setting). The heater was installed on one side, and on the other side, a heat reflecting plate with an aluminum plate plated with gold was installed. The heater unit can be adjusted up and down and front and back, and the heater unit can be finely adjusted in the front and rear direction (see arrow direction in the figure). The heated roller 304 is loosely inserted into the work carrier 302 and passes through the heater unit while being heated along a horizontal arrow in the figure by a chain drive (not shown). When the work carrier 302 enters the heater heating effective range, the work carrier 302 rotates with the roller 304 at 60 revolutions per minute. In heating, the temperature of the roller 304 is raised to a target temperature range when it passes through the temperature raising unit 311. In order to shorten the vulcanization tact time, the roller 304 is then passed through the temperature holding unit 312 and heated by irradiation with infrared rays for a predetermined time.

(Shaft core)
In the present invention, a cored bar (metal shaft core) can be used as the shaft core. Examples of the core metal include a cylindrical core metal and a hollow cylindrical sleeve.

[Elastic layer forming material]
As a material for forming the elastic body layer, there is liquid silicone rubber as a typical liquid resin.

  As the material of the elastic body, solid bodies and foams of various elastic materials such as silicone rubber, urethane rubber, EPDM, NBR, hydrin rubber, thermoplastic rubber, etc. can be used, and physical properties such as resistance adjustment and strength improvement can be used. Various additives that modify the mechanical properties can also be used. These liquid raw materials can be vulcanized and cured to form the elastic layer.

[Elastic roller]
FIG. 5 schematically shows an example of the structure of the elastic roller with a surface layer formed by the manufacturing method of the present invention. This elastic roller has a shaft core body 101 that is usually formed of a conductive material such as metal at the center, and an elastic body layer (base layer) 102 is fixed on the outer peripheral surface of the shaft core body 101. The conductive layer (surface layer) 103 is laminated on the outer peripheral surface of the layer 102.

  The elastic roller obtained in the present invention is suitable as a conductive roller, and particularly suitable as a developing roller used in an electrophotographic process.

[Image forming apparatus]
FIG. 6 is a cross-sectional view for explaining a schematic configuration of an example of an electrophotographic process cartridge and an image forming apparatus used for image evaluation of the present invention. The image forming apparatus includes an electrophotographic process cartridge (developing apparatus) 35 using an elastic roller obtained by the present invention as a developing roller. In addition to the developing roller, the elastic roller obtained by the present invention can be used as at least one of a charging roller, a transfer roller, a fixing roller, and a pressure roller. FIG. 6 shows a black-and-white image forming apparatus. In a color image forming apparatus, the developing device 35 shown in FIG. 6 is usually arranged side by side in yellow, magenta, cyan, and black.

  In this image forming apparatus, the photosensitive drum 21 as a latent image carrier rotates in the direction of arrow A, and the region of the photosensitive drum 21 that has passed therethrough is uniformly charged by the charging roller 22 for charging the photosensitive drum 21. Further, in this charged region, an electrostatic latent image is formed on the surface by the laser beam 23 which is an exposure means for writing the electrostatic latent image. The electrostatic latent image is arranged close to the photosensitive drum 21 and is developed by applying toner as a developer by a developing device 35 that can be attached to and detached from the main body of the image forming apparatus, and visualized (visualized) as a toner image. Is done.

  For development, a method such as so-called reversal development in which a toner image is formed on the exposed portion can be used. The visualized toner image (image) on the photosensitive drum 21 is transferred to a transfer material 33 such as paper by a transfer roller 29. The paper 33 to which the toner image has been transferred is fixed by the fixing roller 32 and the pressure roller 36, and is discharged out of the apparatus, thus completing the printing operation. The transfer roller 29 is a region that holds the toner image on the photosensitive drum 21 by pressing the transfer paper 33 from the back surface thereof to transfer the toner image onto the surface of the transfer paper. On the contrary, the toner image transfer is promoted by being charged. The transfer sheet 33 is pressed against the surface of the photosensitive drum 21 by automatically inserting the transfer sheet 33 into a portion where the photosensitive drum 21 and the transfer roller 29 are in contact with each other. Achieved.

  On the other hand, the untransferred toner remaining on the photosensitive drum 21 without being transferred is scraped off by the cleaning blade 30 and stored in the waste toner container 31, and the above process is repeated on the cleaned photosensitive drum 21. The same image can be copied or a new image can be transferred.

  In the illustrated example, the developing device 35 is located opposite to the photosensitive drum 21 in a developing container 34 containing a non-magnetic toner 28 as a one-component developer, and an opening extending in the longitudinal direction in the developing container 34. And a developing roll 25 as a developer carrier, and the electrostatic latent image on the photosensitive drum 21 is developed and visualized.

  The developing roller 25 is in contact with the photosensitive drum 21 with a contact width. In the developing device, the developer supply roller 26 having elasticity contacts the upstream side of the developing roller 25 in the rotation direction (arrow B direction) with respect to the contact portion of the elastic blade 27 with the surface of the developing roller 25 in the developing container 34. It is in contact with and is rotatably supported. As the structure of the developer supply roller 26, a foamed skeleton-like sponge structure or a fur brush structure in which fibers such as rayon and nylon are planted on a cored bar supplies toner 28 to the developing roller 25 and peels off undeveloped toner. It is preferable from the point of taking. For example, a developer supply roller 26 having a diameter of 12 mm and a charging roller 22 having a polyurethane foam on a core metal can be used.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited by this. First, various measurement methods will be described.

<Roller temperature measurement method>
The elastic roller surface temperature in the heated state was measured using an infrared camera device TH-2B manufactured by NEC Corporation with the roller rotating. This measuring device can measure both instantaneous and instantaneous.

<Measurement and evaluation method of outer diameter accuracy of elastic layer>
The elastic roller was allowed to stand for 24 hours or more in an environment at a temperature of 25 ° C. and a relative humidity of 45%, and then the following measurement was performed.

As shown in FIG. 3, a total of 5 outer diameters are measured at intervals of about 52 mm from both ends of the roller using a laser length measuring machine (trade name: PULCOM (registered trademark) opt 60B-600, manufactured by Tokyo Seimitsu Co., Ltd.). This was performed while rotating 360 °, and the average was taken as the outer diameter at each point. Furthermore, the outer diameters at the five measured points were compared, the difference between the maximum value and the minimum value was taken, and if the value was less than 30 μm, ◎,
If it is 30 μm or more and less than 50 μm,
If it is 50 μm or more, it was evaluated as Δ.

<Development roller and charging roller image evaluation method>
The manufactured elastic roller was incorporated as a developing roller and a charging roller in a black developing device (electrophotographic process cartridge) of Color Laser Jet 3700 (trade name) manufactured by HP, and an evaluation image was output and used for image evaluation. The environment for outputting the evaluation image was set to a temperature of 25 ° C. and a relative humidity of 45%. For the evaluation image, an image in which a line having a width of 1 dot and an interval of 2 dots was written in the direction perpendicular to the rotation direction of the photosensitive member was used. After that, if the appropriate density is obtained visually, and if the image quality is good, ◎,
If the density is slightly thin or density unevenness is slightly seen,
If the density is low and density irregularities are seen, △
Image evaluation after passing 6000 sheets in A4 size was performed.

  A liquid silicone rubber containing the following carbon black was prepared as an elastic body forming material.

  DY35-1265 (trade name) manufactured by Toray Dow Corning Silicone Co., Ltd. A material: 100 parts by mass and B material: 100 parts by mass.

  10 parts by mass of carbon black (Mitsubishi Chemical, trade name: MA11) was added to each of the A material and B material, mixed and defoamed for 5 minutes with a rotating mixer, and used as a liquid resin for forming an elastic body.

  As the shaft core (core metal), a round bar-shaped steel metal core having a diameter of 6 mm and a length of 275 mm was prepared, and the surface thereof was subjected to chemical nickel plating.

<Coating process>
First, using the ring coating apparatus, the elastic body forming material was applied to the outer peripheral surface of the steel cored bar to obtain a conductive roller base layer (a liquid resin layer before curing) before vulcanization. . As the ring-shaped coating apparatus, the one shown in FIG. 1 was used. The coating head 8 of this apparatus has the configuration shown in FIG. The coating head was designed and manufactured so that the thickness of the liquid resin layer before vulcanization was about 3 mm.

  The shaft core 101 was moved in the vertical direction from the upper side to the lower side of the coating head 8 (FIG. 1), passed through the coating head, and once positioned below the molding head. Next, a liquid resin layer was formed on the outer peripheral surface of the shaft core by the coating head while moving the shaft core vertically upward.

<Primary vulcanization process>
Next, the liquid resin layer was heated with a heating device to be primarily cured. As the heating device used for the primary curing, an infrared heating device based on the above principle was used, and in Example 1, only the unit 311 of the heating part for raising the temperature of the unvulcanized roller was used. Since the heater has an effective width of 600 mm, the moving speed of the work carrier 302 was set to 3.33 mm / second so that the passage time was 180 seconds. As shown in FIGS. 15 and 16, the heating conditions were such that all heater outputs were unified at 9%, the distance was c = 30 mm, and they were heated in a straight line (FIG. 10) for 180 seconds.

<Evaluation of outer diameter after primary vulcanization>
FIG. 17 and FIG. 12 show the results of measuring the outer diameter after primary vulcanization in accordance with the roller outer diameter accuracy measuring method. The difference in outer diameter was 32 μm. The target roller outer diameter after the primary curing was 11.98 mm. Several trials of molding, primary vulcanization, and outer diameter measurement were repeated, but since the roller surface temperature was 200 ° C. when a predetermined outer diameter was obtained, 200 ° C. was set as the set temperature thereafter.

<Secondary heating process>
Subsequently, an elastic base layer for a conductive roller vulcanized to the center was obtained by secondary vulcanization using a hot air circulation dryer manufactured by Satake Chemical Machinery Co., Ltd. at 200 ° C. for 2 hours.

<Surface layer forming step>
Subsequently, a polyol (manufactured by Nippon Polyurethane, trade name: NIPPOLAN (registered trademark) 5033) diluted with MEK so as to be a mixed solution having a solid content of 12%, an isocyanate compound (manufactured by Nippon Polyurethane, 10 parts by mass of a product name: Coronate (registered trademark) L) was added to 100 parts by mass of the polyol component, and the mixture was sufficiently stirred to obtain a resin raw material liquid. And after immersing and coating the base layer provided with the elastic body layer for the conductive roller in this resin raw material liquid, it is pulled up and dried, and it is heated to 130 ° C. with a hot air circulation dryer manufactured by Satake Chemical Industry Co., Ltd. For 20 minutes, and a resin layer having an average film thickness of about 20 to 30 μm was provided on the outer periphery of the elastic base layer.

<Image evaluation>
In this way, a plurality of conductive rollers were produced. When this conductive roller was used as a developing roller and a charging roller and image evaluation was performed by the above-described image evaluation method, a good image could be obtained. The obtained results are shown in FIG.

  A liquid resin layer was formed on the outer peripheral surface of the shaft core body using the same elastic body forming material, cored bar, and coating apparatus as those used in Example 1. Next, the liquid resin layer was heated and cured by a heating device. As shown in FIG. 8, the heating device of the second embodiment includes a heating unit 311 for raising the temperature of the unvulcanized roller, and an infrared ray so that the output of the infrared heater can be lowered and the temperature of the unvulcanized roller can be maintained. Two units 312 of the heat insulating part that irradiates the light are arranged in series. There was no heater output adjustment and distance adjustment, and since the heater effective width was 600 mm, the moving speed of the work carrier 302 was set to 10 mm / second so that the passing time was 60 seconds.

Heating unit: (heater center 20%) x (60 seconds heating)
Thermal insulation unit: (heater center 9%) x (60 seconds heating)
Was heated continuously using two heater units. See FIGS. 15 and 16 for detailed heating conditions.

  It took 5 seconds to move between the two units. Therefore, the total heating time was 125 seconds. The purpose of the second embodiment is to shorten the tact time. FIG. 4 shows the results of measuring the surface temperature of the central portion of the roller being heated over time with the roller rotating. The vertical axis is the surface temperature of the roller center, and the horizontal axis is the elapsed time.

<Evaluation of outer diameter after primary curing>
FIG. 17 and FIG. 12 show the results of measuring the outer diameter after primary vulcanization in accordance with the roller outer diameter accuracy measuring method. The difference in outer diameter was 49 μm.

<Image evaluation>
Thereafter, as in Example 1, secondary vulcanization and surface coating were performed to produce a plurality of conductive rollers. When this conductive roller was used as a developing roller and a charging roller and image evaluation was performed by the above-described image evaluation method, a good image could be obtained. The obtained results are shown in FIG.

  A liquid resin layer was formed on the outer peripheral surface of the shaft core body using the same elastic body forming material, cored bar, and coating apparatus as those used in Example 1. Next, the liquid resin layer was heated by a primary vulcanizer and primary vulcanized. As shown in FIGS. 11 and 15, the heating device used for the primary vulcanization of Example 3 heated the elastic roller by changing the distance of the halogen lamp heater in the longitudinal direction of the heater. The code dimensions in FIG. 11 are d = 27, e = 32, and c = 37 (mm). The purpose of Example 3 is to make the temperature distribution uniform.

<Evaluation of outer diameter after primary curing>
FIG. 17 and FIG. 12 show the results of measuring the outer diameter after primary vulcanization in accordance with the roller outer diameter accuracy measuring method. The difference in outer diameter was 18 μm.

<Image evaluation>
Thereafter, as in Example 1, secondary vulcanization and surface coating were performed to produce a plurality of conductive rollers. When this conductive roller was used as a developing roller and a charging roller and image evaluation was performed by the above-described image evaluation method, a good image could be obtained. The obtained results are shown in FIG.

  A liquid resin layer was formed on the outer peripheral surface of the shaft core body using the same elastic body forming material, cored bar, and coating apparatus as those used in Example 1. Next, the liquid resin layer was heated by a primary vulcanizer and primary vulcanized. As shown in FIG. 11 and FIG. 15, in the heating device in Example 4, the distance of the halogen lamp heater was changed in the front-rear direction of the heater in order to supplement heat radiation from both ends of the roller, and the heater output was adjusted for the same purpose. (See FIGS. 15 and 16). The elastic roller was heated. The purpose of Example 4 was to further homogenize the temperature distribution, and combined the conditions for the most uniform temperature distribution. The result of measuring the heating temperature distribution at the timing immediately before the end of heating is shown in FIG. The vertical axis represents the roller surface temperature. In Example 4, the temperature distribution was uniform compared to Example 1 in which the distances and outputs of all the heaters were the same.

<Evaluation of outer diameter after primary curing>
FIG. 17 and FIG. 12 show the results of measuring the outer diameter after primary vulcanization in accordance with the roller outer diameter accuracy measuring method. The difference in outer diameter was 9 μm.

<Image evaluation>
Thereafter, as in Example 1, secondary vulcanization and surface coating were performed to produce a plurality of conductive rollers. When this conductive roller was used as a developing roller and a charging roller and image evaluation was performed by the above-described image evaluation method, a good image could be obtained. The obtained results are shown in FIG.

(Comparative Example 1)
A liquid resin layer was formed on the outer peripheral surface of the shaft core body using the same elastic body forming material, cored bar, and coating apparatus as those used in Example 1. Next, the following heating apparatus was prepared. One 200V × 1200W model made by USHIO ELECTRIC CO., LTD. Is used as the halogen heater, and the axis of the roller 304 and the axis of the heater 320 are arranged parallel to each other as shown in FIG. Arranged (horizontal). The roller was rotated at 60 revolutions per minute during heating. The distance between the roller surface and the heater axis was C = 50 mm. With this apparatus, the liquid resin layer was irradiated with infrared rays and heated to primarily vulcanize the roller. It took 240 seconds to reach the set temperature of 200 ° C.

<Evaluation of outer diameter after primary curing>
FIG. 17 and FIG. 12 show the results of measuring the outer diameter after primary vulcanization in accordance with the roller outer diameter accuracy measuring method. The difference in outer diameter was 51 μm. Because the heating temperature distribution in the roller axis direction cannot be adjusted with a single heater, the outer diameter difference increased compared to the example. The reason why the roller and the heater are arranged horizontally is to avoid the influence of the heat quantity of heating due to convection.

<Image evaluation>
Thereafter, as in Example 1, secondary vulcanization and surface coating were performed to produce a plurality of conductive rollers. When this conductive roller was used as a developing roller and a charging roller and image evaluation was performed by the above-described image evaluation method, slight density unevenness occurred, but an image having no practical problem could be obtained. The obtained results are shown in FIG.

(Comparative Example 2)
A liquid resin layer was formed on the outer peripheral surface of the shaft core body using the same elastic body forming material, cored bar, and coating apparatus as those used in Example 1. Next, the following heating apparatus was prepared. As in the case of Comparative Example 1, one 200V × 1200W type made by USHIO ELECTRIC CO., LTD. Is used as the halogen heater, and the axis of the roller 304 and the axis of the heater 320 are arranged in parallel as shown in FIG. Arranged perpendicular to the direction of gravity (vertical type). The roller was rotated at 60 revolutions per minute during heating. The distance between the roller surface and the heater axis was C = 50 mm. With this apparatus, the liquid resin layer was irradiated with infrared rays and heated to primarily vulcanize the roller. It took 240 seconds to reach the set temperature of 200 ° C.

<Evaluation of outer diameter after primary curing>
FIG. 17 and FIG. 12 show the results of measuring the outer diameter after primary vulcanization in accordance with the roller outer diameter accuracy measuring method. The difference in outer diameter was 100 μm. The reason why the outer diameters of the measurement positions I (1) and V (5) deviated remarkably was that the heating was moved upward in the roller axis direction due to the vertical arrangement, and the roller axis upward direction (see FIG. 3). The temperature rises in comparison with the lower direction of the roller shaft, and as a result, the curing of the upper part of the roller proceeds and the outer diameter is presumed to be reduced. The reason why the roller and the heater are arranged vertically is to avoid the influence that the uncured liquid resin layer becomes uneven due to gravity.

<Image evaluation>
Thereafter, as in Example 1, secondary vulcanization and surface coating were performed to produce a plurality of conductive rollers. When this conductive roller was used as a developing roller and a charging roller and image evaluation was performed by the image evaluation method described above, density unevenness occurred. The obtained results are shown in FIG.

It is a schematic diagram which shows the example of the ring coating machine which can be used for this invention. It is a figure which shows the ring coating head to which the coating method of embodiment was applied. It is a figure which shows the position which measured the temperature measurement position of the elastic body roller, the outer diameter precision, and the deflection in the Example. It is a time-axis graph of the result of having measured the temperature of the elastic body roller in the Example. It is a schematic diagram which shows the structure of the elastic body roller obtained by this invention, (a) is axial direction sectional drawing, (b) is sectional drawing of a direction perpendicular | vertical to an axis | shaft. 1 is a schematic view showing an electrophotographic process cartridge and an image forming apparatus of the present invention. It is a schematic diagram which shows the heating apparatus using an infrared heater, and is a figure showing the state by which an elastic body roller is heated. It is a schematic diagram of the infrared heater unit comprised with a halogen lamp. It is an axial direction temperature distribution graph of the result of having measured the temperature of the elastic body roller, changing the distance of a halogen lamp heater in an Example. It is a figure showing the position of the heater and elastic body roller seen from the heater cross section horizontal direction used for the Example. It is a figure showing the position of the heater and elastic body roller seen from the heater cross section horizontal direction used for the Example, and is the figure which changed the heater position. It is a relationship graph of an outer diameter measurement position and an outer diameter showing the result of an Example and a comparative example. It is a figure showing arrangement | positioning of the horizontal installation single type heater and roller used for the comparative example. It is a figure showing arrangement | positioning of the vertical single heater used for the comparative example, and a roller. It is a table | surface which shows the heating conditions of a heater unit. It is a table | surface which shows an image evaluation result. It is a table | surface which shows an outer diameter measurement result.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base 2 Column 3 Ball screw 4 LM guide 5 Servo motor 6 Pulley 7 Bracket 8 Ring-shaped coating head 9 Workpiece holding shaft 10 Workpiece holding shaft 11 Supply port 12 Piping 13 Material supply valve 14 Linear guide 21 Photosensitive drum ( Image forming body)
DESCRIPTION OF SYMBOLS 22 Charging roller 23 Laser beam 24 Developer hopper 25 Developer roller 26 Developer supply roller 27 Elastic blade 28 Developer (toner)
29 Transfer roller 30 Cleaning blade 31 Waste toner container 32 Fixing roller 33 Paper 34 Developer container 35 Developer (process cartridge)
36 Pressure roller 101 Axis body 102 Elastic body layer (before or after curing)
DESCRIPTION OF SYMBOLS 103 Surface layer 201 Ring head upper part 202 Ring head lower part 203 Material injection port 204 Material flow path 205 Material discharge port 301 Halogen (infrared) heater aggregate 302 Work carrier 303 Reflecting plate 304 Heated roller 311 Temperature rising part 312 Temperature holding part 320 Halogen (infrared) heater unit

Claims (5)

In the manufacturing method of an elastic body roller, which is manufactured by coating an unvulcanized rubber around the core metal and forming an unvulcanized rubber roller by heating and curing the unvulcanized roller.
The core of the metal core is arranged in the direction of gravity, and a plurality of infrared heaters for heating are arranged in a side wall shape so as to be orthogonal to the unvulcanized roller in the horizontal direction, and infrared rays from the infrared heater are transferred to the unvulcanized roller. A method for producing an elastic roller, characterized in that the material is heated and cured while rotating the unvulcanized roller.   2. The method for producing an elastic roller according to claim 1, wherein at least the infrared heater is constituted by a heating portion for raising the temperature of the unvulcanized roller and a heat retaining portion for keeping the temperature.   An elastic roller, which is heat-cured by the method according to claim 1.   The elastic roller according to claim 3, wherein the elastic roller is a developing roller.   The elastic roller according to claim 3, wherein the elastic roller is a charging roller.

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