JP2007167711A - Surface treatment method for rubber roller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive surface treatment method for a rubber roller with excellent mass production property, reduced dynamic friction coefficient and high quality not generating an image defect such as dust and a foreign matter by continuously performing coating the rubber roller with a surface treatment agent, blowing of air and irradiation with UV ray in a short time. <P>SOLUTION: In the surface treatment method for the rubber roller, the surface treatment agent is delivered to the rubber roller from a ring head and a surface of the rubber roller is coated with it. In the surface treatment method for the rubber roller, and a blowing ring head for blowing the air to the ring head coated with the surface treatment agent and a circular disc-like or helical UV ray lamp for irradiating UV ray are concentrically arranged, the rubber is arranged at its center to continuously perform coating with the surface treatment agent, blowing of the air and irradiation with UV ray. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a surface treatment method (manufacturing method) of a rubber roller (charging roller, developing roller, etc.) used in an image forming apparatus using an electrophotographic process, particularly in OA equipment such as LBP (Laser Beam Printer), copying machine, and facsimile. It is about.

  As image forming apparatuses in recent years increase in speed and durability, rubber rollers used in image forming apparatuses are also required to have high precision and durability.

  The charging roller used in the image forming apparatus is the most common charging member, and performs a charging process in contact with the photosensitive drum. As for the charging roller, many rubber rollers are coated with a paint or a surface treating agent in terms of performance, and adhesion of dust, foreign matter, etc. to the rubber roller surface in the coating process also leads to image defects. In some cases, the coating process is performed in a clean room to prevent dust and foreign matter from adhering to the surface of the rubber roller. However, the inclusion of clean room incidental facilities may result in a very expensive production line.

  Furthermore, when an image endurance test using a halftone image is performed using a charging roller in the image forming apparatus, the surface of the charging roller becomes dirty due to the endurance of the image and external additives attached to the toner. There is. As a result, image defects such as white streaks occur starting from a heavily soiled portion on the surface of the charging roller. This is because the surface of the charging roller becomes dirty, and the photosensitive drum cannot be uniformly charged. One possible cause of contamination of the roller surface is a large dynamic friction coefficient (friction resistance) between the photosensitive drum and the roller surface. When the dynamic friction coefficient is large, an external force is applied to the toner and the external additive and the toner tends to adhere to the roller surface. Therefore, it is very important to reduce the dynamic friction coefficient on the roller surface.

  Here, particularly with respect to the surface treatment method of the rubber roller used in the image forming apparatus, the manufacturing method of continuously performing ring head coating, blowing ring head drying, annular or spiral ultraviolet lamp irradiation as in the present invention. No patent application has been filed.

However, as a method of coating the cylindrical substrate drum (photoreceptor drum), slide hopper coating and ring-shaped suction slit drying are continuously performed, and further, slide hopper coating and ring-shaped suction slit drying are stacked in two or more layers to form a multilayer. Methods that can be applied have been studied (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3). This does not relate to the surface treatment method of the rubber roller, and neither describes the application to the elastic layer (rubber roller). Also, the coating head structure and the drying head structure / method are different, and there is no description about the combination with irradiation using an annular or spiral ultraviolet lamp.
JP-A-5-099559 JP-A-6-057495 JP-A-10-243398

  The present invention has been made to solve the problems described above.

  That is, the object of the present invention is to prevent image defects due to dust and foreign matter adhering to the surface of the rubber roller in the coating process, to improve charging performance, and to reduce the dynamic friction coefficient of the roller, and to stabilize a rubber roller that does not have poor image durability. It is to provide a surface treatment method for a roller to be manufactured.

  The present inventors have intensively studied to solve the above problems, and after applying the surface treatment agent from the ring head to the surface of the rubber roller, continuously blowing air from the slit-like outlet (blow-out ring head). By carrying out the process, it is possible to prevent dust, foreign matter and the like from adhering to the surface of the rubber roller. Furthermore, after applying with a ring head and drying with a blow-off ring head, an annular or spiral ultraviolet lamp is continuously placed on the surface of the rubber roller to irradiate with ultraviolet rays, thereby curing the material on the surface of the rubber roller or the roller. It is possible to reduce the dynamic friction coefficient or both simultaneously. As a result, it has been found that the mass productivity can be improved and the surface treatment process of the rubber roller can be reduced, and the present invention has been completed.

  The surface treatment method for a rubber roller according to the present invention is such that after a surface treatment agent is applied from the ring head to the surface of the rubber roller, the air blowing from the blowing ring head is continuously performed, and further, the application by the ring head and the blowing ring head. After drying by the above, an annular or spiral ultraviolet lamp is continuously arranged on the surface of the rubber roller and irradiated with ultraviolet rays, thereby preventing the adhesion of dust, foreign matter, etc. to the rubber roller surface. Further, it is possible to simultaneously cure the material on the surface of the rubber roller and / or reduce the dynamic friction coefficient of the roller. As a result, it is possible to stably obtain an excellent rubber roller that is free from image defects due to adhesion of dust, foreign matter, and the like, and that is free from roller contamination and image durability failure due to a large dynamic friction coefficient of the rollers. Further, the surface treatment process of the rubber roller 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 having a rubber layer provided on a core metal, a material is obtained by assembling two cylindrical pieces concentrically holding a shaft core metal in a cylindrical mold, and heating after injecting a rubber material. After the rubber material is extruded and 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 integrally extruded to form a cylindrical rubber roller. There are extrusion molding, transfer molding, press molding and the like, but there is no particular limitation. In view of shortening the production time, extrusion molding in which a rubber roller is formed by extruding a rubber material integrally with a metal core is preferable.

  Regarding the method of heating the rubber roller, any method such as a hot stove, vulcanizing can, hot platen, far / near infrared, induction heating, etc. may be used, and a method of pressing while rotating on a heated cylindrical or planar member May be used.

  In some cases, dry grinding using a rotating grindstone may be performed to obtain a desired roller shape and roller surface roughness after heating.

  Here, FIG. 1 shows a schematic diagram of an extruder. The extruder 1 includes a crosshead 2. The crosshead can insert the cored bar 4 fed by the cored bar feeding roller 3 from behind, and can simultaneously extrude the cylindrical rubber material simultaneously with the cored bar. After the rubber material was formed in a cylindrical shape around the core metal, the end portion was cut and removed 5 to obtain a rubber roller 6.

  The material used as the metal core of the rubber roller 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 SUM material. The rubber layer provided on the metal core is a conductive elastic layer, and as the polymer, natural rubber, butadiene rubber, hydrin rubber, styrene-butadiene rubber, nitrile rubber, ethylene-propylene rubber, butyl rubber, silicone rubber, Any of urethane rubber, fluorine rubber, chlorine rubber, thermoplastic elastomer, etc. may be used. Examples of conductive powder dispersed in the polymer include carbon black, carbon such as conductive carbon, metal powder, conductive fiber, tin oxide, etc. Any of these semiconductive metal oxide powders and mixtures thereof may be used.

  Next, the surface treatment method for the rubber roller of the present invention will be described in detail.

  First, a rubber roller obtained by the above-described method or the like is supported in a vertical state, and a slit-like discharge port (ring head) that is opened around the circumference at a predetermined distance from the rubber roller, a ring Liquid distribution for the surface treatment agent supplied from one or more supply ports provided in the ring head to be combined in the ring head and distributed in the circumferential direction by liquid supply means (syringe pump) outside the head Using a ring head with one or more chambers and one or more liquid constrictions, the rubber roller and the ring head are moved relative to each other at a predetermined speed (about 1 to 100 mm / s), and an appropriate amount of surface treatment agent is uniformly distributed around the circumference Only apply to rubber roller surface. Here, FIG. 2 shows a ring head coating method, a rubber roller 6 and a ring head 7. Reference numeral 8 denotes a slit-like discharge port opened on the entire circumference, 9 denotes a liquid throttle portion, 10 denotes a liquid supply port, and 11 denotes a liquid distribution chamber.

  The discharge amount to the rubber roller surface is calculated in consideration of the liquid viscosity of the surface treatment agent and the surface treatment speed (relative movement speed between the rubber roller and the ring head). The opening width (slit width) of the slit-like discharge port opened on the entire circumference of the ring head is 0.05 mm or more, preferably 0.1 mm (the slit width is the liquid viscosity of the surface treatment agent, addition in the surface treatment agent) Selected and determined by the material). As the surface treatment agent, silicone-based, fluorine-based, urethane-based, acrylic-based, urethane-modified acrylic-based, and silicone-modified urethane-based are particularly used. Here, the surface treating agent includes both those that form a film on the surface of the rubber roller and those that are impregnated from the surface of the rubber roller. As a material of the ring head, it is preferable to use a steel material such as stainless steel having high processing accuracy. Aluminum, fluorine resin, or the like may be used.

  By applying the surface treatment agent to the surface of the rubber roller by the ring head application method as described above, a slit-like air outlet (air outlet) that is continuously opened at a predetermined distance from the rubber roller. Air is blown from the ring head), or an annular or spiral ultraviolet lamp is disposed at a predetermined distance from the rubber roller, and both are irradiated continuously.

  First, air blowing from the blowing ring head will be described. The rubber roller is supported vertically and is blown out by a slit-like air outlet (blow-off ring head) that is opened at a predetermined distance from the rubber roller and air supply means outside the ring head. One or more air distribution chambers for merging and distributing the air supplied from one or more air supply ports provided in the ring head in the ring head in the circumferential direction, and one or more air throttling portions. The blowing roller head causes the rubber roller and the ring head to move relative to each other at a predetermined speed (about 1 to 100 mm / s), and air is blown uniformly on the surface of the rubber roller. Here, the air blowing ring head method, the rubber roller 6, and the blowing ring head 12 are shown in FIG. Reference numeral 13 denotes a slit-like air outlet that is opened all around, 14 is an air throttle, 15 is an air supply port, and 16 is an air distribution chamber.

  As for the amount (flow rate) of air blown onto the surface of the rubber roller, the desired width of the air blow can be adjusted by arbitrarily adjusting the opening width (slit width) of the slit-like blower opening that is opened all around the blow ring head and the diameter of the blower outlet. Determine the amount (flow rate). The air pressure is adjusted within a range of 0.01 to 1 MPa where no repelling of the rubber roller surface (coating layer) or coating layer unevenness occurs. As the air blown from the blow ring head, dry air, hot air, air temperature / humidity may be arbitrarily set and used. Further, nitrogen may be purged instead of air. Depending on the surface treatment agent applied here, by controlling the temperature, flow rate, and pressure of the hot air blown from the blow ring head, the moisture content of the surface treatment agent containing moisture can be controlled and from the surface of the rubber roller to the inside. It is possible to control the gradient concentration of fluorine groups or silicone groups. As the material of the blowout ring head, it is preferable to use a steel material such as stainless steel having high processing accuracy. Aluminum, fluorine resin, or the like may be used.

  Next, irradiation of ultraviolet rays by an annular or spiral ultraviolet lamp will be described. The rubber roller is supported in a vertical state, and an annular or spiral ultraviolet lamp is disposed at a distance from the rubber roller at a predetermined interval, and the rubber roller and the annular or spiral ultraviolet lamp are moved at a predetermined speed (1 The rubber roller is irradiated uniformly over the entire circumference with relative movement at about 100 mm / s). The speed is determined in consideration of the UV integrated light quantity. Further, it is preferable to increase the efficiency by arranging an ultraviolet reflector outside the annular or spiral ultraviolet lamp. Further, when the rubber roller and the annular or spiral ultraviolet lamp are relatively moved to irradiate ultraviolet rays, the rubber roller itself may be rotated. Here, FIG. 4 shows an ultraviolet irradiation method using an annular ultraviolet lamp, a rubber roller 6 and an annular ultraviolet lamp 17. Reference numeral 18 denotes an ultraviolet reflector.

  The number of annular or spiral ultraviolet lamps arranged on the surface of the rubber roller and the outer diameter of the ultraviolet lamp can be set arbitrarily, taking into consideration the influence of heat from the outer diameter of the rubber roller, the accumulated UV light quantity, and radiation from the lamp. Determined.

  The ultraviolet lamp may be any of a high-power low-pressure mercury lamp, an electrodeless low-pressure mercury lamp, an excimer lamp, a high-pressure mercury lamp, and a metal halide lamp, and may be appropriately selected according to the effect of the surface treatment. In the present invention, a high-power low-pressure mercury lamp is used, which is mainly ultraviolet light having a wavelength of 254 nm. Here, the spectral distribution of the ultraviolet lamp (low pressure mercury lamp) used in the present invention is shown in FIG. 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. This time, for ultraviolet rays typified by a wavelength of 254 nm, the integrated light amount of the ultraviolet rays was measured using a UIT-150-A, UVD-S254 ultraviolet intensity meter and integrated light meter manufactured by USHIO INC.

  In addition, as the material of the reflector disposed outside the annular or spiral ultraviolet lamp, aluminum, stainless steel, and iron are used, and the reflective surface is mirror-finished or is subjected to coating treatment or surface treatment for improving the reflectance. Things are desirable. Preferably, the surface is made of high purity aluminum having a material of 99.9% or more, and the surface is subjected to gloss alumite treatment having a reflectance of 90% or more. Here, in the case of a reflector made of stainless steel with a mirror finish, the reflectance of ultraviolet rays is about 80%, and in the case of a reflector made of high-purity aluminum with a gloss anodized surface, the reflectance of ultraviolet rays is 90% or more. It is. The distance between the reflecting plate and the rubber roller can be arbitrarily set, and is determined in consideration of the influence of heat by ultraviolet integrated light quantity and radiation from the reflecting plate.

  In order to increase the wettability of the rubber roller surface before applying the surface treatment agent to the surface of the rubber roller, it is possible to irradiate the ultraviolet ray with an annular or spiral ultraviolet lamp. In addition, when the surface treatment agent is applied to the surface of the rubber roller and then irradiated with ultraviolet rays, depending on the surface treatment agent to be applied, it is possible to simultaneously perform both the material hardening of the rubber roller surface and the modification of the rubber roller surface. .

  The present invention relates to a rubber roller in which the surface treatment agent is applied to the surface of the rubber roller by a ring head, the air is then blown from the blowing ring head, the ultraviolet ray is irradiated by an annular ultraviolet lamp, or both. This is a surface treatment method. The order of the application of the ring head, the blowing of air from the blowing ring head, and the irradiation of ultraviolet rays by an annular or spiral ultraviolet lamp may be arbitrarily determined depending on the purpose.

  The rubber roller obtained by the ultraviolet irradiation method of the rubber roller according to the embodiment of the present invention is used as an electrophotographic member of an image forming apparatus such as an LBP (Laser Beam Printer), a copying machine, or a facsimile. Here, FIG. 6 shows a usage pattern when used as a charging roller. The image forming apparatus is a rotating drum type / transfer type electrophotographic apparatus, and 19 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 is uniformly charged to a predetermined polarity and potential (-600 V in this embodiment) by a charging roller 20 to which a charging bias is applied from a power source E1 as a charging means during its rotation process, and then an exposure system. By receiving a negative image exposure (analog exposure of the original image, digital scanning exposure) corresponding to the target image information, the 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 22 of a reverse developing method using minus toner. Then, a transfer material is fed at a predetermined timing from a sheet feeding means (not shown) to the transfer portion between the photosensitive drum and the transfer roller 23 as the transfer means, and the toner image is supplied to the transfer roller from the power source E2 by about +2. A toner image that has been reversely developed on the surface of the photosensitive drum by applying a transfer bias of ˜3 KV 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 and introduced into fixing means (not shown) to undergo image fixing processing. The surface of the photosensitive drum 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 24 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, after the surface treatment agent is applied from the ring head to the surface of the rubber roller, the air blowing from the blowing ring head is continuously performed. In addition, after applying with a ring head and drying with a blow-off ring head, an annular or spiral ultraviolet lamp is continuously placed on the rubber roller surface to irradiate with ultraviolet rays, thereby dust on the rubber roller surface. , Prevent adhesion of foreign substances. Further, it is possible to simultaneously cure the material on the surface of the rubber roller and / or reduce the dynamic friction coefficient of the roller. As a result, it is possible to stably obtain an excellent rubber roller that is free from image defects due to adhesion of dust, foreign matter, and the like, and that is free from roller contamination and image durability failure due to a large dynamic friction coefficient of the rollers. Further, the surface treatment process of the rubber roller can be reduced.

  In the measurement of the dynamic friction coefficient in the present invention, a sheet-like body (for example, a metal film such as stainless steel or a plastic film such as PET) having one end connected to a load cell or a tension gauge and a constant load W applied to the other end, The sheet-like body is slid on the roller surface by contacting the surface of the fixed roller with a predetermined winding angle θ (90 ° in the embodiment) and rotating the roller at a constant speed in the direction of the arrow. Evaluation was made with a roller friction coefficient measuring machine adapted to detect the tension T. The tension T detected at this time was applied to the following Euler's equation to determine the dynamic friction coefficient μ.

μ = (1 / θ) · ln (T / W)
μ: Coefficient of dynamic friction θ: Winding angle (radian)
W: Load (g)
T: Tension (g)
The dynamic friction coefficient was measured using a plastic film (thickness 25 μm, width 30 mm) under the conditions of a total load W of 100 g and a roller rotation speed of 115 ppm.

  The measurement was performed in an environment of 23.5 ° C./60%.

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

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

・ Epichlorohydrin rubber 100 parts by mass (trade name “Epichromer (Epichromer is a registered trademark) CG102” manufactured by Daiso Corporation)
-MT carbon 5 parts by mass (trade name “HTC # 20”: made by Nisshin Carbon)
-5 parts by mass of zinc oxide-1 part by mass of stearic acid Furthermore, 1 part by mass of vulcanization accelerator (DM: di-2-benzothiazolyl disulfide), 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 core roller and a rubber material were integrally extruded using an extruder schematically shown in FIG. 1 to form a rubber roller. Thereafter, heat vulcanization was performed at 160 ° C. for 2 hours, and further, dry polishing using a rotating grindstone, and cutting / removal processing of the end portion, a rubber roller having a thickness of 1.25 mm and a length of 232 mm was obtained (rubber roller outer diameter φ8. 5 mm).

<Surface treatment method>
Put a silicone-modified urethane-based surface treatment agent in a sealed container, connect the sealed container to a syringe pump that is a liquid supply means, and then connect it to one liquid supply port provided in the ring head. Treatment agent was supplied. The surface treatment agent was filled in the ring head having a liquid distribution chamber for joining and distributing in the circumferential direction in the ring head. The rubber roller obtained above was supported in a vertical state, and the ring head was arranged so that a slit-like discharge port opened on the entire circumference at a distance of 0.5 mm from the outer diameter of the rubber roller. . At this time, the opening width (slit width) of the slit-like discharge port opened on the entire circumference of the ring head was 0.1 mm. The ring head is vertically moved from the upper end to the lower end of the rubber roller at a constant speed of 10 mm / s, and at the same time, an appropriate amount (0.07 mL) of surface treatment agent is applied uniformly at the entire circumference at a discharge speed of 0.003 mL / s. went.

Three annular low-pressure mercury lamps are arranged concentrically with the ring head, and after the ring head application, the annular low-pressure mercury lamp is continuously vertically moved to irradiate with ultraviolet rays. . Three annular low-pressure mercury lamps were vertically moved from the upper end to the lower end of the rubber roller at a constant speed of 1 mm / s. Regarding the low-pressure mercury lamp, the ultraviolet light mainly representing a wavelength of 254 nm was used, and the cumulative amount of ultraviolet light at this time was about 3600 mJ / cm ² . In addition, a high-purity aluminum reflector (ultraviolet ray reflectivity of 90% or more) subjected to gloss alumite treatment was used outside the annular low-pressure mercury lamp.

  FIG. 7 shows a schematic diagram of ultraviolet irradiation by the ring head application and three annular low-pressure mercury lamps. Here, the structure of the manufactured rubber roller is shown in FIG.

  In this embodiment, the surface treatment agent was applied to the surface of the rubber roller, and then the ultraviolet ray was continuously irradiated. Therefore, the surface treatment agent could be dried and cured immediately after application, and the surface of the rubber roller was attached with dust, foreign matter, etc. There was almost no. As a result of visually observing the surface of the rubber roller, no dust, foreign matter or the like of 100 μm or more was observed in one rubber roller. Further, the surface of the rubber roller was modified by irradiation with ultraviolet rays, and the result of measuring the dynamic friction coefficient of the rubber roller was 0.23.

  Further, this rubber roller is incorporated as a charging roller in the electrophotographic image forming apparatus shown in FIG. 6, and is pressed against each end of the photosensitive drum under a load of 500 g, and is half-cut in an environment of 23.5 ° C./60%. A continuous image evaluation of 6000 continuous images using tone images was performed. In this evaluation, the rubber roller (charging roller) of the present example did not show any dirt on the roller surface, and there was no defective image due to the dirt, and a good image could be obtained. The results are shown in Table 1.

<Production of rubber roller>
A rubber roller was obtained in the same manner as in Example 1 (rubber roller outer diameter φ8.5 mm).

<Surface treatment method>
A silicone surface treating agent containing an alkyl fluoride group was applied to the surface of the rubber roller by the same ring head application method as in Example 1.

  The blowing ring head was arranged concentrically with the ring head, and after applying the ring head, the blowing ring head was continuously moved vertically to blow air. The air supply means was connected to one air supply port provided in the blowing ring head, and air was supplied into the blowing ring head. Air was supplied into the ring head having an air distribution chamber for merging and distributing in the circumferential direction in the ring head. The above-obtained rubber roller was supported in a vertical state, and the blowout ring head was arranged so that a slit-like blowout opening opened to the entire circumference at a distance of 1 mm from the outer diameter of the rubber roller. At this time, the opening width (slit width) of the slit-shaped air outlet that was opened around the entire circumference of the ring head was 0.5 mm. The ring head was vertically moved at a constant speed of 10 mm / s from the upper end portion to the lower end portion of the rubber roller, and at the same time, air with a pressure of 0.1 MPa was blown uniformly over the entire circumference. Moreover, the air supplied in the blowing ring head this time used the air previously heated at about 120 degreeC.

  Further, three annular low-pressure mercury lamps are arranged concentrically with the ring head and the blowing ring head, and after applying the ring head and blowing air with the blowing ring head, the first embodiment is performed. In the same way as above, UV irradiation was performed by continuously moving an annular low-pressure mercury lamp vertically.

  FIG. 9 shows a schematic diagram of the application of the ring head, the air blowing by the blowing ring head, and the ultraviolet irradiation by the three annular low-pressure mercury lamps. Here, the structure of the manufactured rubber roller is shown in FIG.

  In this example, the surface treatment agent was applied to the surface of the rubber roller, and then the hot air was continuously blown and irradiated with ultraviolet rays. There was no adhesion of dust and foreign matter. As a result of visually observing the surface of the rubber roller, no dust or foreign matter was observed in one rubber roller. Further, the surface of the rubber roller was modified by irradiation with ultraviolet rays, and the result of measuring the dynamic friction coefficient of the rubber roller was 0.21.

  Further, this rubber roller is incorporated as a charging roller in the electrophotographic image forming apparatus shown in FIG. 6, and is pressed against each end of the photosensitive drum under a load of 500 g, and is half-cut in an environment of 23.5 ° C./60%. A continuous image evaluation of 6000 continuous images using tone images was performed. In this evaluation, the rubber roller (charging roller) of the present example did not show any dirt on the roller surface, and there was no defective image due to the dirt, and a good image could be obtained. The results are shown in Table 1.

[Comparative example]
<Production of rubber roller>
A rubber roller was obtained in the same manner as in Example 1 (rubber roller outer diameter φ8.5 mm).

<Surface treatment method>
After applying the silicone-modified urethane-based surface treatment agent on the surface of the rubber roller by the same ring head coating method as in Example 1, the rubber roller was handled and conveyed to a drying oven for heat treatment having an internal volume of about 200 L. The surface treatment agent was dried and cured at 160 ° C. for 30 minutes.

  As a result of visually observing the surface of the rubber roller, about 10 dusts, foreign matters, etc. of 100 μm or more in one rubber roller were observed.

  Further, this rubber roller is incorporated as a charging roller in the electrophotographic image forming apparatus shown in FIG. 6, and is pressed against each end of the photosensitive drum under a load of 500 g, and is half-cut in an environment of 23.5 ° C./60%. Initial image evaluation by tone images was performed. In this evaluation, about 20 black spots were generated in one A4 sheet. The results are shown in Table 1.

Schematic diagram of extruder Schematic diagram of ring head application Schematic diagram of air blowing ring head Schematic diagram of annular UV lamp irradiation Spectral distribution of low-pressure mercury lamp Configuration diagram showing outline of image forming apparatus Schematic diagram of ring head application and irradiation of three annular UV lamps Sectional view of a rubber roller made according to an embodiment of the present invention Schematic diagram of ring head application, air blowing ring head and 3 annular UV lamp irradiation

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Extruder 2 Extruder crosshead 3 Core metal feed roller 4 Core metal 5 Cutting / removal processing 6 Rubber roller 7 Ring head 8 Slit-like discharge port 9 opened in the whole circumference 9 Liquid throttle part 10 Liquid supply port 11 Liquid distribution Chamber 12 Blow-out ring head 13 Slit-like discharge port opened to the entire circumference 14 Air throttle 15 Air supply port 16 Air distribution chamber 17 Annular ultraviolet lamp 18 Ultraviolet reflector 19 Electrophotographic photosensitive member (photosensitive drum)
20 Charging roller (charging means)
21 exposure system 22 developing roller (developing means)
23 Transfer roller (transfer means)
24 Cleaning means E1, E2, E3 Power supply for bias application 25 Rubber layer 26 Ultraviolet irradiation treatment layer 27 Coating layer of surface treatment agent

Claims (2)

  The surface treatment agent is discharged from a slit-like discharge port (ring head) opened at the entire circumference at a distance from the rubber roller provided with the first elastic layer on the core metal, and the surface treatment agent is removed from the rubber roller. In the surface treatment method of the rubber roller applied to the surface, a step of blowing air from a slit-like outlet (ring head) opened at the entire circumference at a distance from the rubber roller, and the rubber roller is spaced. A method for treating a surface of a rubber roller, comprising: arranging at least one annular or spiral ultraviolet lamp at a distance and irradiating the ultraviolet ray with at least one step.   The surface treatment method for a rubber roller according to claim 1, wherein a ring head for blowing air to a ring head for applying a surface treatment agent to the surface of the rubber roller, and an annular or spiral ultraviolet lamp for irradiating ultraviolet rays A surface treatment method for a rubber roller, characterized in that the rubber roller is disposed concentrically and a rubber roller is disposed at the center for continuous surface treatment.

Images