JP2005212372A - Method and equipment for surface treatment of elastic member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and equipment for surface treatment of an elastic member which can perform the surface treatment of the elastic member by an energy beam, controlling surface roughness and maintaining uniformity thereof, by reducing the change in the surface roughness of the elastic member caused by exposure to the energy beam, with regard to the surface of the elastic member (rubber roller) used for an image forming apparatus utilizing an electrophotographic process. <P>SOLUTION: In the method and equipment for the surface treatment of the elastic member, the surface of the elastic member (rubber roller) used for the image forming apparatus utilizing the electrophotographic process is pressed against a member being in a heated state and having a smooth or indented surface shape and is exposed to ultraviolet rays or electron beams. This makes it possible to perform the uniform controlled surface treatment, while controlling the surface roughness of the elastic member and maintaining the uniformity of the surface roughness. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention is based on LBP (Laser Beam
The present invention relates to a surface treatment method and a surface treatment apparatus for an elastic member (charging roller, developing roller, etc.) such as a charging roller and a developing roller used in an image forming apparatus using an electrophotographic process in OA equipment such as a printer, a copying machine, and a facsimile. Is.

  Conventionally, as a method of controlling the surface roughness of the elastic member (rubber roller), a method of polishing the surface of the rubber roller and controlling the surface roughness according to the conditions (for example, refer to Patent Document 1) or extrusion molding the rubber roller. A method of controlling the surface roughness by applying irregularities to the die portion of the extruder used in the case (see, for example, Patent Document 2) or pressing the surface of a rubber roller against a metal member having irregularities that are heated in advance. A method for controlling the surface roughness by using this method has been studied. In any case, it is considered that the surface roughness can be controlled.

  However, after adjusting the surface roughness to a certain value in any of the above cases, for example, for the purpose of reducing the adhesive strength of the surface of the elastic member, reducing the dynamic friction coefficient, curing the surface layer, etc. There are cases where surface treatment is performed by energy beam irradiation (see, for example, Patent Document 1 and Patent Document 3), but it is considered that the surface roughness of the roller changes before and after irradiation due to energy beam irradiation. (For example, surface roughness may be increased by irradiation with ultraviolet rays). Therefore, it is considered very difficult to control the final surface roughness.

  Further, the surface treatment method and surface treatment of an elastic member (rubber roller) that suppresses a change in surface roughness caused by irradiating the surface of the rubber roller with energy rays and performs surface treatment with energy rays while controlling the surface roughness. There is no description about the device.

JP-A-9-160355 Japanese Patent Laid-Open No. 8-074835 Japanese Patent Laid-Open No. 1-187165

  In recent years, image forming apparatuses have been required to have high accuracy and high durability as components such as elastic members used in the image forming apparatus have been increased in speed and durability.

  For example, with respect to the charging roller, there is a problem that the charging roller becomes durable when the image durability test is performed, and the roller surface is soiled by toner, external additives, and the like. As a result, an image defect occurs. One of the causes of the roller surface becoming dirty is that the surface roughness of the roller is large, and toner and external additives may adhere to portions where the surface roughness is non-uniform. Uniform control is very important.

  For example, with respect to the developing roller, when the surface roughness of the roller is small and the surface roughness is non-uniform, there is a problem that variation in toner charging characteristics (charge amount, etc.) supplied from a toner supply roller (not shown) becomes large. This may cause a problem that the amount of supplied toner is not stable, and it becomes difficult to stably supply the toner to the photosensitive drum.

  Therefore, it is very important to maintain the uniformity of the surface roughness while controlling the uniform control of the surface roughness of the elastic member (rubber roller) used in the image forming apparatus using the electrophotographic process.

  Here, the surface of the elastic member may be subjected to a surface treatment by irradiation with energy rays such as ultraviolet rays or electron beams for the purpose of reducing the adhesive force on the surface of the elastic member, reducing the dynamic friction coefficient, curing the surface layer, pretreatment of the coating, etc. However, the surface roughness of the elastic member may change before and after irradiation due to irradiation with energy rays (for example, the surface roughness may increase due to irradiation with ultraviolet rays). In the conventional example, the rubber surface of the polished roller may be irradiated with ultraviolet rays. In this case, the surface roughness may change after the polishing finish and after irradiation with ultraviolet rays. It is considered very difficult to control the thickness.

  SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide an elastic member by irradiating the surface of an elastic member (rubber roller) used in an image forming apparatus using an electrophotographic process with an energy beam. By controlling the surface roughness and controlling the surface roughness while maintaining the uniformity of the surface roughness, the surface treatment of the elastic member with energy rays can suppress the surface roughness of the elastic member with excellent image characteristics. An object of the present invention is to provide a surface treatment method and a surface treatment apparatus for an elastic member capable of uniform control of the surface and surface treatment of the elastic member with energy rays.

  In order to achieve the above object, the present invention relates to a surface treatment method for an elastic member, wherein the surface of the elastic member is pressed against a heated member, and the surface of the elastic member is irradiated with energy rays. The heated member is a metal member having a curved or flat surface shape and a smooth or uneven surface shape. The surface of the elastic member is pressed against the member, and energy such as ultraviolet rays or electron beams is used. The present invention proposes a surface treatment method for an elastic member characterized by irradiating a line.

  Also, a surface treatment apparatus for an elastic member is provided, characterized by comprising means for pressing the surface of the elastic member against a heated member and means for irradiating the surface of the elastic member with energy rays. To do. Thereby, it is possible to control the surface roughness of the elastic member while maintaining the uniformity of the surface roughness and to perform the surface treatment of the elastic member with energy rays.

  The present invention controls the surface roughness by suppressing the change in the surface roughness of the elastic member caused by irradiating the surface of the elastic member (rubber roller) used in the image forming apparatus using the electrophotographic process with energy rays. While maintaining the uniformity of the surface roughness, the surface treatment of the elastic member with energy rays can be performed. Furthermore, the manufacturing process can be reduced by simultaneously performing uniform control while maintaining the uniformity of the surface roughness while controlling the surface roughness and surface treatment by irradiation with energy rays.

  As a result, for example, due to unevenness in roller dirt or surface roughness due to an increase in the surface roughness of the elastic member due to irradiation of energy rays, the amount of toner is not partially stably supplied, etc. Defects can be suppressed, and the surface roughness of the elastic member with excellent image characteristics can be controlled while maintaining the uniformity of the surface roughness and the surface treatment of the elastic member with energy rays can be performed. Since an elastic member having a uniform thickness and a surface treated with energy rays can be stably obtained in a short time, not only the quality as a product can be improved, but also the manufacturing cost can be reduced.

  Hereinafter, the present invention will be described in more detail with an example of a rubber roller.

  First, as a molding method of a rubber roller in which a rubber layer is provided on a cored bar, a material is obtained by assembling two cylindrical pieces concentrically holding a shaft-shaped cored bar in a cylindrical mold, and heating after injecting a rubber material. Is molded by molding the rubber roller, after the rubber material is extruded into a tube shape, the core metal is covered with the tube-shaped rubber material, or the core metal and the rubber material are extruded together to form a cylindrical rubber roller. Extrusion molding, transfer molding, press molding, etc. are not particularly limited, but in order to uniformly control the surface roughness, the rubber layer on the core metal is preferably an unvulcanized rubber The extrusion molding in which the unvulcanized rubber layer is formed on the core metal by extruding the unvulcanized rubber integrally with the core metal is preferable.

  Here, FIG. 1 shows a schematic diagram of an extruder used in the present invention.

  The extruder 1 includes a crosshead 2, and the crosshead 2 can insert the cored bar 4 fed from the cored bar feed roller 3 from behind, and simultaneously presses the cylindrical unvulcanized raw material simultaneously with the cored bar 4. Can be put out. After molding cylindrical unvulcanized rubber around the core metal 4, the end portion was cut and removed 5 to obtain an unvulcanized rubber roller 6.

  The material used as the core metal 4 of the unvulcanized rubber roller 6 is preferably a stainless steel rod, a phosphor bronze rod, an aluminum rod, or a heat resistant resin rod containing a steel material such as a nickel-plated or chrome-plated SUM material. The rubber layer provided on the cored bar 4 is a conductive elastic layer, and polymers include natural rubber, butadiene rubber, hydrin rubber, styrene-butadiene rubber, nitrile rubber, ethylene-propylene rubber, butyl rubber, and silicone rubber. , Urethane rubber, fluorine rubber, chlorine rubber, thermoplastic elastomer, etc., and conductive powder dispersed in the polymer may be carbon black, carbon such as conductive carbon and metal powder, conductive fiber, or oxidized Any of semiconductive metal oxide powders such as tin, and a mixture thereof may be used. However, in the case of a thermoplastic material, the progress of vulcanization is irrelevant, so it is better to press against a member heated to a temperature above the softening point.

  The material of the heated member that presses against the surface of the unvulcanized rubber roller obtained by the method as described above is preferably a metal such as stainless steel, iron, aluminum, copper, or brass, and further has high thermal conductivity, It is preferable to use a metal with high processing accuracy. The pressing member may be surface-treated, and coated with fluorine coating, fluorine resin / silicone resin, etc. in addition to plating such as chrome plating and nickel plating so that unvulcanized rubber does not stick. Or a surface treatment of a known metal can be used.

  Next, the shape and surface shape (surface roughness) of the pressing member will be described.

  As the shape of the pressing member, a member longer than the length of the rubber portion of the unvulcanized rubber roller is preferably used, and the pressing surface may be a flat shape, but is preferably a curved surface or a flat shape.

  First, the case where the pressing surfaces of the pressing member and the unvulcanized rubber roller have a curved shape will be described.

  Specifically, a cylindrical pressing member may be used. In the case of a cylindrical pressing member, pressure is applied while continuously changing the position by pressing the unvulcanized rubber roller against the rotating pressing member while pressing both ends of the core bar and rotating it. be able to. As the cylindrical pressing member, a cylindrical member having an inner diameter larger than the outer diameter of the unvulcanized rubber roller may be used and rotated while being pressed against the inner peripheral surface.

  Next, a case where the pressing surfaces of the pressing member and the unvulcanized rubber roller have a planar shape will be described.

  Specifically, a flat pressing member may be used. In the case of a flat plate-shaped pressing member, pressure can be applied while continuously changing the position by pressing both ends of the core metal and rolling on the unvulcanized rubber roller while pressing it.

  In order to make the obtained rubber roller into a crown shape or a reverse crown shape with different outer diameters in the longitudinal direction, the shortest distance from the central axis of the cored bar passing through the center of both ends of the cored bar to the pressing member is the longitudinal direction of the cored bar. Different pressing members may be used depending on the positions. With the rotation of the pressing, the outer diameter in the longitudinal direction of the roller is deformed so as to follow the shortest distance from the pressing member, and a desired outer diameter shape can be obtained.

  Specifically, when the pressing member is cylindrical, the crown shape (the outer diameter of the central portion is larger than the outer diameter of the end portion) or the reverse crown shape (the outer diameter of the central portion is the outer diameter of the end portion) Heating may be performed using a smaller pressing member. Alternatively, an unvulcanized roller having an outer diameter difference may be used and pressed against a heated pressing member.

  About the surface shape (surface roughness) of the pressing member, in order to obtain the desired surface shape (surface roughness), the surface of the rubber roller is made to have the same surface roughness as the desired surface shape (surface roughness). It is possible to control the roughness.

  As the feeding speed of the pressing member, the moving speed may be adjusted so that vulcanization of the surface of the unvulcanized roller proceeds by heating so that no trace remains, and the pressing speed may be reciprocated.

  As for the method of heating the pressing member, any method such as a hot stove, a vulcanizing can, a hot platen, far / near infrared rays, induction heating, etc. may be used in combination, and it is uniform at a temperature in the range of 140 ° C to 220 ° C. It is preferable to be heated.

  Regarding the heating method of the unvulcanized rubber roller, any method such as a hot blast furnace, a vulcanizing can, a heating plate, far / near infrared rays, induction heating and the like may be used together with the pressing member. It is preferable to heat at a temperature in the range for 10 minutes to 120 minutes. Further, a temperature gradient may be applied to the pressing member within the heating time.

  The pressure load applied to the pressing member of the unvulcanized rubber roller can be adjusted as appropriate depending on the viscosity of the rubber material, and depending on the weight of the core metal, only its own weight may be used. It is preferable to multiply at least one by one. The load may be applied by any method such as air pressure.

  Next, energy beam irradiation will be described.

  The energy rays applied to the surface of the rubber roller are ultraviolet rays or electron beams, and the surface is irradiated by rotating the rubber roller.

  For irradiation with ultraviolet rays, a high pressure mercury lamp, a metal halide lamp, a low pressure mercury lamp, or an excimer UV lamp is used. Among these, high-pressure mercury lamps and metal halide lamps emit near-ultraviolet rays in the near-ultraviolet region typified by a wavelength of 365 nm. The low-pressure mercury lamp emits short-wavelength ultraviolet rays having wavelengths of 185 nm and 254 nm, which are shorter than near ultraviolet rays. In addition, the excimer UV lamp emits ultraviolet light having a peak at 172 nm, which is shorter than other short wavelength ultraviolet light, and having no other peak. For ultraviolet irradiation, it is preferable to use a low-pressure mercury lamp or excimer UV lamp. The integrated light quantity of ultraviolet rays is defined below.

UV integrated light quantity (mJ / cm ² ) = UV intensity (mW / cm ² ) × irradiation time (sec)
What is necessary is just to select suitably about the integrated light quantity of an ultraviolet-ray according to the effect of surface treatment. The adjustment can be performed by any of irradiation time, lamp output, and distance between the lamp and the roller, and may be determined so as to obtain a desired integrated light quantity. Further, a gradient may be given to the integrated light quantity within the irradiation time.

  This time, for low-pressure mercury lamps, the cumulative amount of ultraviolet light is measured using the UIT-150-A, UVD-S254 ultraviolet cumulative light meter made by USHIO, Inc., and for the excimer UV lamp, the cumulative amount of ultraviolet light is measured. The measurement was performed using a UIT-150-A, VUV-S172 ultraviolet integrated light meter manufactured by USHIO INC.

  The electron beam irradiation is performed using an electron beam irradiation apparatus (manufactured by Iwasaki Electric Co., Ltd.) having an acceleration voltage of 150 kV and an electron current of 40 mA. Also, nitrogen gas purge is performed during irradiation. The electron beam dose is defined below.

Dose (kGy) = [equipment constant × electron current (mA)] / processing speed (m / min)
What is necessary is just to select suitably about the dose of an electron beam according to the effect of surface treatment. The adjustment can be performed by either the electronic current or the processing speed, and it may be determined so as to obtain a desired dose. Further, the dose may be graded within the irradiation time.

  This time, we measured the dose at a certain electron current and processing speed in advance using a dose film, calculated the device constant, and calculated the electron beam dose based on it.

  FIG. 2 is a schematic diagram (A is a front view, B is a side view) of an irradiation pressure heating apparatus having a cylindrical pressing member used in the present invention and a portion irradiated with energy rays.

  The rotating cylindrical pressing member 7 and the center of the unvulcanized rubber roller 6 extruded integrally with the core metal are held in parallel, and the holding member 7 for pressurizing both ends of the unvulcanized rubber roller 6. Is held so that the shaft does not shift from side to side. The pressing member 7 is provided with a heating infrared heater (halogen lamp heater) 9 at the center, and is preheated to a heating temperature. By rotating the pressing member 7 by the motor 10, the unvulcanized rubber roller 6 can be driven to rotate. Further, the pressing force can be adjusted by changing the load 11. Further, the irradiation port 12 is arranged so that the energy beam is irradiated to the unvulcanized rubber roller 6, and the pressing of the unvulcanized rubber roller 6 on the pressing member 7 and the irradiation of the energy beam are performed simultaneously. Is possible.

  In the case where a large number of cylinders are manufactured at the same time, it is necessary to prepare as many cylindrical members as there are when using cylindrical pressing members. It is only necessary to press a large number of rollers against a portion rotated by driving with a roller or the like, and the apparatus can be simplified. The material of the belt-like member is preferably a metal such as SUS or nickel that has strength and good thermal conductivity.

  FIG. 3 is a schematic diagram (A is a front view, B is a side view) of an irradiation pressure heating apparatus having a belt-like pressing member and a portion irradiated with energy rays.

  Reference numeral 13 denotes a belt-like pressing member, 14 denotes a roller for rotationally driving the belt, 11 denotes a load for pressing the unvulcanized roller, and 12 denotes an irradiation port for irradiating the unvulcanized rubber roller with energy rays.

  The rubber roller obtained by the rubber roller surface treatment method according to the embodiment of the present invention is used as a charging and developing roller used in an image forming apparatus such as an LBP (Laser Beam Printer), a copying machine, or a facsimile. Is shown in FIG.

  The image forming apparatus is a rotary drum type / transfer type electrophotographic apparatus, and 15 is an electrophotographic photosensitive member (photosensitive drum) as an image carrier, which rotates clockwise at a predetermined peripheral speed (process speed). Driven. The photosensitive drum 15 is uniformly charged at a predetermined polarity / potential (-600 V in this embodiment) by a charging roller 16 to which a charging bias is applied from a power source E1 as a charging means during the rotation process. The exposure system 17 receives negative image exposure (analog exposure of the original image, digital scanning exposure) corresponding to the target image information, and an electrostatic latent image of the target image information is formed on the peripheral surface.

  Next, the electrostatic latent image is developed as a toner image by a toner developing roller 18 of a reversal developing method using minus toner. The toner image is fed at a predetermined timing from a sheet feeding means (not shown) to a transfer portion between the photosensitive drum 15 and a transfer roller 19 as a transfer means, and a power source E2 is supplied to the transfer roller 19. Then, a transfer bias of about +2 to 3 kV is applied, and the reversely developed toner image on the surface of the photosensitive drum 15 is sequentially transferred onto the transfer material. The transfer material that has received the transfer of the toner image is separated from the surface of the photosensitive drum 15 and introduced into fixing means (not shown) to undergo image fixing processing. The surface of the photosensitive drum 15 after the transfer of the toner image is subjected to a removal process of adhering contaminants such as transfer residual toner by the cleaning unit 20 to be cleaned and repeatedly used for image formation.

  As described above, according to the rubber roller surface treatment method according to the embodiment of the present invention, the surface of the rubber roller is pressed against a heated member, and the surface of the rubber roller is irradiated with energy rays. Because it is possible to control the surface roughness of the rubber roller with energy rays while controlling the surface roughness and maintaining the uniformity of the surface roughness while suppressing the change in the surface roughness of the rubber roller by irradiating the energy rays A rubber roller having a uniform surface roughness and a surface treated with energy rays, and can be manufactured stably in a short time.

  Moreover, the measurement of the surface roughness of the pressing member and the rubber roller in the present invention was performed by a method according to the ten-point average roughness (Rz) evaluation in JIS-B-0601.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to these.

<Production of unvulcanized rubber roller>
The following raw materials were kneaded with an open roll for 30 minutes.

・ 100 parts by mass of epichlorohydrin rubber (trade name “Epichromer CG102”: manufactured by Daiso Corporation)
-MT carbon 5 parts by mass (trade name “HTC # 20”: made by Nisshin Carbon)
・ Zinc oxide 5 parts by mass ・ Stearic acid 1 part by mass Further, vulcanization accelerator (DM: di-2-benzothiazolyl disulfide) 1 part by mass, vulcanization accelerator (TS: tetramethylthiuram monosulfide) 0. 5 parts by mass and 1.2 parts by mass of sulfur as a vulcanizing agent were added and kneaded with an open roll for 15 minutes to prepare an unvulcanized rubber composition. Next, a stainless bar core bar having an outer diameter of 6 mm and a length of 258 mm was prepared. Here, a cylindrical unvulcanized rubber composition was formed around the core metal by integrally extruding the core metal and rubber using the extruder schematically shown in FIG. Thereafter, the end portion was cut and removed so that the length of the unvulcanized rubber composition was 232 mm to obtain an unvulcanized rubber roller (unvulcanized rubber roller outer diameter φ8.5 mm).
<Surface treatment method>
The unvulcanized rubber roller was pressed against a cylindrical heating member simultaneously with ultraviolet irradiation by a low-pressure mercury lamp using an irradiation pressure welding heating apparatus schematically shown in FIG. The cylindrical heating member was previously heated to 180 ° C. Further, the unvulcanized rubber roller was pressed and vulcanized while rotating for 10 minutes to obtain a rubber roller. A load of 1 kg was applied to both ends of the unvulcanized rubber roller. The surface roughness of the cylindrical heating member is Rz 1.0 μm, and UV irradiation is performed using a low-pressure mercury lamp (manufactured by Harrison Toshiba Lighting) so that the integrated light quantity is 5000 mJ / cm ² with a wavelength of 254 nm. did.

  As a result of measuring the surface roughness of the rubber roller, it was Rz 1.3 μm. Further, this rubber roller was incorporated in an electrophotographic cartridge as a charging roller, pressed against each end of the photosensitive drum under a load of 500 g, and halftone image evaluation was performed using this rubber roller (charging roller). In this evaluation, a good image could be obtained by the rubber roller (charging roller) of this example. Furthermore, even as a result of the image durability test, it was possible to obtain a good image without contamination of the rubber roller (charging roller). The results are shown in Table 1.

<Production of unvulcanized rubber roller>
An unvulcanized rubber roller was obtained in the same manner as in Example 1 except that the final diameter of the final unvulcanized rubber roller was 12 mm.
<Surface treatment method>
The unvulcanized rubber roller was pressed against a cylindrical heating member simultaneously with ultraviolet irradiation by an excimer UV lamp using an irradiation pressure heating apparatus schematically shown in FIG. The cylindrical heating member was previously heated to 200 ° C. Further, the unvulcanized rubber roller was pressed and vulcanized while rotating for 20 minutes to obtain a rubber roller. A load of 1 kg was applied to both ends of the unvulcanized rubber roller.

The surface roughness of the cylindrical heating member is Rz 8.0 μm, and for ultraviolet irradiation, an excimer UV lamp (manufactured by Harrison Toshiba Lighting) is used to irradiate ultraviolet light having a wavelength of 172 nm so that the integrated light quantity becomes 1000 mJ / cm ^2. did. As a result of measuring the surface roughness of the rubber roller, it was Rz 7.8 μm. Further, this rubber roller was incorporated as a developing roller into an electrophotographic cartridge, pressed against the photosensitive drum in a state where the amount of penetration was 60 μm, and image evaluation was performed by halftone using this rubber roller (developing roller). In this evaluation, a good image could be obtained with the rubber roller (developing roller) of this example. The results are shown in Table 1.

<Production of unvulcanized rubber roller>
An unvulcanized rubber roller was obtained by the same method as in Example 1 (outer diameter of unvulcanized rubber roller φ8.5 mm).
<Surface treatment method>
The unvulcanized rubber roller was pressed against a cylindrical heating member at the same time as the electron beam irradiation using an irradiation pressure welding heating apparatus schematically shown in FIG. The cylindrical heating member was previously heated to 180 ° C. Further, the unvulcanized rubber roller was pressed and vulcanized while rotating for 10 minutes to obtain a rubber roller. A load of 1 kg was applied to both ends of the unvulcanized rubber roller.

  The surface roughness of the cylindrical heating member was Rz 1.0 μm, and electron beam irradiation was performed in nitrogen gas so that the electron beam dose was 800 kGy depending on the electron current and irradiation time.

As a result of measuring the surface roughness of the rubber roller, it was Rz 1.1 μm. Further, this rubber roller was incorporated in an electrophotographic cartridge as a charging roller, pressed against each end of the photosensitive drum under a load of 500 g, and halftone image evaluation was performed using this rubber roller (charging roller). In this evaluation, a good image could be obtained by the rubber roller (charging roller) of this example. Furthermore, even as a result of the image durability test, a good image could be obtained without contamination of the rubber roller (charging roller). The results are shown in Table 1.
[Comparative Example 1]
<Production of unvulcanized rubber roller>
An unvulcanized rubber roller was obtained by the same method as in Example 1 (outer diameter of unvulcanized rubber roller φ8.5 mm).
<Surface treatment method>
The unvulcanized rubber roller was pressed against a cylindrical heating member using a pressure heating device, and only heat vulcanization was performed. The cylindrical heating member was previously heated to 180 ° C. Further, the unvulcanized rubber roller was pressed and vulcanized while rotating for 10 minutes to obtain a rubber roller. A load of 1 kg was applied to both ends of the unvulcanized rubber roller. The surface roughness of the cylindrical heating member was Rz 1.0 μm. As a result of measuring the surface roughness of the rubber roller at this time, it was Rz 1.4 μm.

Thereafter, the rubber roller was subjected to surface treatment only by ultraviolet irradiation with a low-pressure mercury lamp using an ultraviolet irradiation device of a low-pressure mercury lamp. With respect to ultraviolet irradiation, ultraviolet light having a wavelength of 254 nm was irradiated with a low-pressure mercury lamp (manufactured by Harrison Toshiba Lighting) so that the integrated light amount was 5000 mJ / cm ² . As a result of measuring the surface roughness of the rubber roller, it was Rz 5.2 μm. In addition, this rubber roller was incorporated in an electrophotographic cartridge as a charging roller, pressed against each end of the photosensitive drum under a load of 500 g, and a halftone image durability test was performed using this rubber roller (charging roller). As a result, the rubber roller (charging roller) was soiled and a good image could not be obtained. The results are shown in Table 1.
[Comparative Example 2]
<Production of rubber roller>
An unvulcanized rubber roller was obtained in the same manner as in Example 2 (unvulcanized rubber roller outer diameter φ12 mm). Thereafter, heat vulcanization was performed at 170 ° C. for 15 minutes, and a rubber roller having a thickness of 1.25 mm and a length of 232 mm was produced by dry polishing using a rotating grindstone (rubber roller outer diameter φ8.5 mm). As a result of measuring the surface roughness of the rubber roller at this time, it was Rz 6.3 μm.
<Surface treatment method>
The rubber roller was subjected to surface treatment only by ultraviolet irradiation with a low-pressure mercury lamp using an ultraviolet irradiation device of a low-pressure mercury lamp. With respect to ultraviolet irradiation, ultraviolet light having a wavelength of 254 nm was irradiated with a low-pressure mercury lamp (manufactured by Harrison Toshiba Lighting) so that the integrated light amount was 5000 mJ / cm ² .

  As a result of measuring the surface roughness of the rubber roller, it was Rz 10.7 μm. Further, this rubber roller was incorporated in an electrophotographic cartridge as a developing roller, pressed into a photosensitive drum in a state where the amount of penetration was 60 μm, and image evaluation by halftone was performed using this rubber roller (developing roller). In this evaluation, since the surface roughness of the rubber roller (development roller) of this comparative example was non-uniform, the toner could not be stably supplied to the photosensitive drum, and the image density unevenness occurred and a good image was obtained. Could not get. The results are shown in Table 1.

  The present invention is highly applicable to an elastic member such as a charging roller and a developing roller used in an image forming apparatus such as an LBP utilizing an electrophotographic process, a copying machine, or a facsimile.

It is a schematic diagram of an extruder. It is a schematic diagram (A is a front view, B is a side view) of the irradiation press-contact heating apparatus of a cylindrical pressing member. It is a schematic diagram (A is a front view, B is a side view) of the irradiation press-contact heating apparatus of a belt-shaped pressing member. 1 is a schematic configuration diagram of an image forming apparatus.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Extruder 2 Extruder crosshead 3 Core metal feed roller 4 Core metal 5 Cutting / removal processing 6 Unvulcanized rubber roller 7 Cylindrical pressing member 8 Holding member 9 Heating infrared heater 10 Motor 11 Load 12 Irradiation port 13 Belt-shaped pressing member 14 Roller for rotationally driving the belt 15 Electrophotographic photosensitive member (photosensitive drum)
16 Charging roller (charging means)
17 Exposure system 18 Developing roller (developing means)
19 Transfer roller (transfer means)
20 Cleaning means E1-E3 Power supply for bias application

Claims (4)

In the surface treatment method of the elastic member,
A surface treatment method for an elastic member, wherein the surface of the elastic member is pressed against a heated member, and the surface of the elastic member is irradiated with energy rays.   2. The elastic member according to claim 1, wherein the member in a heated state is a curved surface or a planar shape, and is heated in a temperature range of 20 to 500 ° C. with a metal member having a smooth or uneven surface shape. Surface treatment method.   The surface treatment method for an elastic member according to claim 1 or 2, wherein the energy rays irradiated to the surface of the elastic member are ultraviolet rays.   A surface treatment apparatus for an elastic member, comprising: means for pressing the surface of the elastic member against a heated member; and means for irradiating the surface of the elastic member with energy rays.

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