JP6270471B2 - Method for producing elastic roller - Google Patents

Description

The present invention relates to the production how the elastic roller can be used in the electrophotographic image forming apparatus.

  A method is known in which the surface of a rubber elastic layer of an elastic roller having a rubber elastic layer is irradiated with an electron beam to crosslink the surface side of the rubber elastic layer, thereby modifying the surface of the rubber elastic layer ( Patent Document 1).

  On the other hand, as a method for easily measuring the electron dose, a method is known in which a transparent film that is colored by irradiation with an electron beam is used, and the electron dose irradiated according to the degree of coloring of the transparent film is obtained (Patent Document 2).

JP 2010-256617 A Japanese Utility Model Publication No. 63-174084

  The inventors use an electron beam irradiation apparatus having a filament of a predetermined length, and have a predetermined width in the axial direction of the core metal with respect to the surface of the rubber elastic layer covering the peripheral surface of the core metal. In this study, the surface of the rubber elastic layer is efficiently modified by simultaneously irradiating with an electron beam. In the process, there was a case where the hardness unevenness in the axial direction of the core metal occurred on the surface of the rubber elastic layer irradiated with the electron beam. Therefore, the present inventors have investigated the cause of such hardness unevenness. As a result, due to deterioration of the filament of the electron beam irradiation device over time, the electron dose from the filament may become non-uniform in the longitudinal direction, thereby reducing the surface modification of the rubber elastic layer. It was found that unevenness occurred and the above hardness unevenness was brought about.

  In order to improve the quality of an electrophotographic elastic roller whose surface has been modified using an electron beam, it is necessary to suppress the occurrence of the above-mentioned hardness unevenness. For this purpose, the present inventors have recognized that it is important to observe the electron dose irradiated to the rubber elastic layer in real time.

  Here, as a method for measuring the electron dose, a method using a transparent film that is colored by irradiation with an electron beam as in Patent Document 2 is known. It is possible to calculate the electron dose from the degree of coloring of the film. However, the film-type dosimeter according to Patent Document 2 requires about 5 minutes until the coloring of the film irradiated with the electron beam is stabilized, and is not suitable for measuring the electron dose in real time.

Therefore, an object of the present invention is to prevent unevenness of hardness in the axial direction of the rubber elastic layer surface when the rubber elastic layer surface is cured by simultaneously irradiating an electron beam to a predetermined axial width of the rubber elastic layer. An object of the present invention is to provide a method capable of producing a high-quality elastic roller while suppressing generation .

According to the present invention, there is provided a method for producing an elastic roller having a cored bar and a rubber elastic layer formed around the cored bar, the surface of the rubber elastic layer being cured by an electron beam ,
Of the surface of the rubber elastic layer covering around the metal core, with respect to the axial direction of the full width of the metal core, the electron beam from the electron beam source through the permeable foil electron beam, irradiation An electron beam irradiation process to radiate,
The electron beam irradiation step includes
By irradiating the electron beam between the surface of the rubber elastic layer and the foil in a nitrogen gas atmosphere having an oxygen concentration of 1000 ppm by volume or less, the surface of the rubber elastic layer and the foil Generating excitation light from the nitrogen gas in the space part between the rubber elastic layer in the full axial width ;
By monitoring the excitation light in the space portion between the surface of the rubber elastic layer and the foil with a CCD camera over a range including the entire width of the rubber elastic layer in the axial direction, Observing the irradiation state of the electron beam on the surface of the rubber elastic layer in the full width in the axial direction ,
An elastic roller manufacturing method is provided.

According to the present invention, a high-quality elastic roller can be stably and more easily controlled by controlling the electron dose unevenness in the axial direction of the elastic roller to be small by using the result of measuring the irradiated electron dose in real time. it is possible to provide a manufacturing how the elastic roller can be produced by Do manufacturing process.

It is a schematic diagram for demonstrating the manufacturing method of the elastic roller of this invention. It is the schematic which shows an example of a structure of the electron beam irradiation apparatus which can be used for the manufacturing method of this invention. It is the schematic which shows the other example of a structure of the electron beam irradiation apparatus which can be used for the manufacturing method of this invention. (B) And (c) is a graph showing the example of inert gas luminescence intensity distribution in the measurement area | region of the rubber roller shown to (a), (d) represents the time-dependent change of the luminescence intensity in the location a of this measurement area | region. It is a graph. It is a schematic diagram for demonstrating the method to convert the detected light emission intensity distribution into electron dose distribution. 6 is a schematic diagram for explaining a method of manufacturing the elastic roller shown in Comparative Example 1. FIG.

  As a result of intensive studies on the above problems, the present inventors have filled the space between the electron beam irradiation source and the rubber roller that is the object to be irradiated with an inert gas, and the inert gas generated by the irradiation of the electron beam. By observing the excitation light, it was found that the intensity distribution of the electron beam at a predetermined width in the axial direction of the rubber roller can be monitored in real time, and the present invention has been achieved.

  That is, in the method for producing an electrophotographic elastic roller according to the present invention, a foil capable of transmitting an electron beam from an electron beam source to the surface of a rubber elastic layer covering the periphery of a cored bar. Through an electron beam irradiation step of irradiating the surface of the core bar with a predetermined width in the axial direction. Then, in the electron beam irradiation step, excitation light from the inert gas is emitted by irradiating the electron beam in an inert gas atmosphere between the surface of the rubber elastic layer and the foil. The rubber elastic layer is generated with a predetermined width in the axial direction, and the intensity distribution of the excitation light in the axial direction is monitored. Thereby, for example, by reflecting the monitoring result in the adjustment of the intensity of the electron beam in the axial direction of the elastic roller, the variation in the degree of surface modification in the predetermined width in the axial direction on the surface of the rubber elastic layer is suppressed to a small level. Will be able to. As a result, a high-quality elastic roller can be manufactured stably and efficiently.

<Elastic roller>
The elastic roller obtained by the present invention has a cored bar and a rubber elastic layer, and the surface (outer peripheral surface) of the rubber elastic layer is modified by curing by electron beam irradiation. This elastic roller can be used, for example, as an electrophotographic elastic roller used in an electrophotographic image forming apparatus. In this specification, a roller before electron beam irradiation having a cored bar and a rubber elastic layer is called a rubber roller, and a roller after electron beam irradiation having a cored bar and a surface-modified rubber elastic layer is an elastic roller. Called.

(Rubber roller)
In the rubber roller used in the present invention, as long as a rubber elastic layer is formed on the core metal, the rubber elastic layer may be formed directly on the outer peripheral surface of the core metal, or between the core metal and the rubber elastic layer. Other layers (for example, an adhesive layer) may be formed.
-Core metal The core metal of the rubber roller can be appropriately selected and used from known metal cores used for electrophotographic elastic rollers. Among them, a stainless steel rod containing a steel material such as nickel-plated SUM, Phosphor bronze bars, aluminum bars, and heat resistant resin bars are preferred.
・ Rubber elastic layer The rubber elastic layer of the rubber roller usually has a binder resin made of a material selected from a thermosetting rubber material in which a raw material rubber is blended with a crosslinking agent such as sulfur and a polymer such as a thermoplastic elastomer. A conductive particle dispersed and combined to have a desired electric resistance is used.

  The raw rubber used for the binder resin is natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), butyl rubber (IIR), ethylene-propylene-diene terpolymer. Rubber (EPDM), epichlorohydrin homopolymer (CHC), epichlorohydrin-ethylene oxide copolymer (CHR), epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer (CHR-AGE), acrylonitrile-butadiene copolymer (NBR) ), Hydrogenated acrylonitrile-butadiene copolymer (H-NBR), chloroprene rubber (CR), acrylic rubber (ACM, ANM) and the like.

  Examples of the thermoplastic elastomer include polyolefin-based thermoplastic elastomers, polystyrene-based thermoplastic elastomers, polyester-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, and vinyl chloride-based thermoplastic elastomers.

  As the material for the binder resin, one kind may be used alone, or two or more kinds may be blended and used.

  The conductive particles dispersed in the rubber elastic layer include conductive carbon such as Ketjen Black EC and acetylene black; carbon for rubber such as SAF, ISAF, HAF, FEF, GPF, SRF, FT, and MT; oxidation treatment Color (ink) carbon applied, pyrolytic carbon, natural graphite, artificial graphite; metals such as tin oxide, titanium oxide, zinc oxide, copper, silver, tin oxide, and metal oxides, and also mixtures thereof .

  The filling amount (use amount) of these conductive particles can be appropriately adjusted according to the types of the binder resin, conductive particles, and other compounding agents, and thereby the electric resistance of the rubber elastic layer can be set to a desired value. Can be adjusted. The amount of the conductive particles used can be, for example, 0.5 parts by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the binder resin, and further 10 parts by mass or more and 70 parts by mass with respect to 100 parts by mass of the binder resin. It is preferable to set it as a mass part or less.

<Electron beam irradiation device>
An electron beam irradiation apparatus that can be used in the production method of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram for explaining a method for producing an elastic roller of the present invention, and FIGS. 2 and 3 are schematic configuration diagrams of an electron beam irradiation apparatus that can be used in the production method of the present invention.
The electron beam irradiation apparatus that can be used in the production method of the present invention can include an electron beam source, a chamber, an inert gas supply unit, and a detection unit.
-Electron beam source In the electron beam irradiation apparatus shown in FIG.2 and FIG.3, it has the filament 11 as an electron beam source which generate | occur | produces an electron beam in the electron beam generation part 14, This electron beam generation part 14 is Furthermore, an acceleration tube 12 for accelerating the electron beam 5 generated by the filament 11 in a vacuum space (acceleration space) is provided. The inside of the electron beam generator 14 is usually vacuumed at 10 ⁻⁶ Pa to 10 ⁻⁷ Pa by a vacuum pump (not shown) in order to prevent electrons from colliding with gas molecules and losing energy. It is kept in.
Chamber These electron beam irradiation apparatuses have a processing chamber 4 for performing surface treatment with the electron beam 5 on the rubber roller 1 composed of the core metal 2 and the rubber elastic layer 3 as a chamber. The processing chamber 4 includes a region in which an object to be processed is disposed and a foil that can transmit the electron beam 5 from the filament 11 (emission port foil 13). In addition, this foil is arrange | positioned in the area | region where the to-be-processed object is arrange | positioned, and the filament 11, specifically, the exit port 8 part shown in FIG. Yes. 2 and FIG. 3 has a region where a workpiece is disposed, and a rubber roller 1 as a workpiece is disposed in this region.

  The exit port foil 13 is usually made of a metal foil, and separates the vacuum atmosphere in the electron beam generator 14 from the atmosphere in the processing chamber 4. The exit port foil 13 enters the processing chamber 4 via the exit port foil 13. 5 is taken out. Therefore, the emission port foil 13 provided at the boundary between the electron beam generation unit 14 and the processing chamber 4 has no pinhole, can ensure the desired airtightness, and can sufficiently maintain the vacuum atmosphere in the electron beam generation unit 14. It is desirable that the electron beam 5 is strong and easily transmitted. For this reason, the exit aperture foil 13 is preferably made of a metal having a small specific gravity and a small thickness, and usually an aluminum foil, a titanium foil, or a beryllium foil is used. For example, a titanium foil having a thickness of about 5 μm to 15 μm is used.

  The rubber roller 1 to be processed is, for example, held by a pair of holding shafts 6 as shown in FIG. 1, and is rotated by a rotating mechanism 7 in the processing chamber 4 by a conveying means (not shown). 3 is conveyed from the left side to the right side (in FIG. 1, the depth direction in the figure (vertical downward direction on the paper surface)). The electron beam generator 14 and the processing chamber 4 are usually shielded from lead (not shown) so that X-rays that are secondarily generated during irradiation with the electron beam 5 do not leak to the outside.

-Inert gas supply means Next, the inert gas supply means of the electron beam irradiation apparatus will be described. The inert gas supply means inactivates the space between the object in the chamber (area where the object is disposed) and the foil, specifically, the space between the surface of the rubber elastic layer and the foil. A gas atmosphere is created. The inert gas supply means used in the present invention can be used as long as the space can be made an inert gas atmosphere. The inert gas supply means (inert gas supply mechanism 9) has a configuration in which one or more gas supply ports are provided in a part of the wall surface (for example, the ceiling surface) of the processing chamber 4 as shown in FIG. it can. Further, the inert gas supply means, for example, as shown in FIG. 3, is an electron beam 5 irradiated from the filament 11 at a position directly below the emission port foil 13 of the electron beam 5 (the lower side in the drawing). It can also be set as the structure which supplies an inert gas from the position which pinches and opposes.

  In the present invention, it is more preferable to use the inert gas supply mechanism 9 having the configuration shown in FIG. In the inert gas supply mechanism 9 shown in FIG. 2, the inert gas ejected from the gas supply port is not directly supplied to the space between the emission port foil 13 and the rubber roller 1, and the inert gas moves. (In FIG. 2, this space is indirectly set to an inert gas atmosphere by moving to the right side of the page). On the other hand, in the inert gas supply mechanism 9 shown in FIG. 3, since the inert gas is directly supplied to the space between the emission port foil 13 and the rubber roller 1, this space is not directly moved without moving. An active gas atmosphere can be obtained. That is, if the inert gas supply mechanism shown in FIG. 3 is used, the inert gas concentration in the processing chamber can be measured by the detection means (monitor mechanism 10) described later, as compared with the inert gas supply mechanism shown in FIG. It is possible to shorten the waiting time until the density range is reached. As a result, the influence on the tact of electron beam irradiation on the rubber elastic layer due to the long standby time can be further reduced.

  Further, in the inert gas supply means shown in FIG. 3, the inert gas supplied from the gas supply port flows downward toward the surface of the rubber elastic layer 3 immediately after jetting, and is positioned above the rubber elastic layer of the rubber roller 1. The fluctuation of the inert gas concentration in the electron beam measurement range 15 can be further reduced. By reducing the concentration change of the inert gas in the electron beam measurement range 15, the electron dose applied to the rubber elastic layer 3 of the rubber roller 1 can be constantly monitored with high accuracy in the axial direction of the rubber roller. In the present invention, not only the inert gas supply means shown in FIG. 3 but also any inert gas supply means having a configuration in which the inert gas concentration unevenness in the electron beam measurement range 15 is reduced is preferably used. Can do.

  In addition, the shape and dimension of the gas supply port which ejects an inert gas can be selected suitably. Examples of the shape of the gas supply port include a circular spot and a slit shape. From the viewpoint of the flow rate of the inert gas to be supplied, the gas supply port is preferably a slit-shaped gas supply port. The slit-shaped gas supply port preferably has a length equal to or greater than the axial width of the rubber elastic layer in the rubber roller 1 from the viewpoint of uniformity of excitation light generated from the inert gas. It is preferable to arrange in parallel (including the case of being substantially parallel) to the axial direction of the elastic layer.

  As described above, in the present invention, the inert gas is ejected from a slit-shaped gas supply port having a length equal to or greater than the width of the rubber elastic layer in the axial direction and parallel to the axial direction. It is preferable to form an active gas atmosphere. In FIG. 3, two gas supply ports are arranged.

-Inert gas The inert gas which forms inert gas atmosphere can be suitably used if it emits light (excitation light is generated) measurable by the electron beam 5. Specific examples include nitrogen, neon, helium, argon, krypton, and xenon. Among these, nitrogen and neon emit light in the visible light region by an electron beam. In addition, helium, argon, krypton, and xenon emit light in the deep ultraviolet region by an electron beam. In the present invention, one of these inert gases is selected and used. Among the above inert gas species, nitrogen is preferable from the viewpoint of ease of handling and running cost.

In the present invention, the intensity of the excitation light from the inert gas by the electron beam 5 irradiated with a predetermined width in the axial direction of the core metal is stabilized, and the degree of coincidence between the intensity distribution of the excitation light and the electron dose distribution is increased. In order to raise, it is preferable to always monitor the inert gas concentration in the processing chamber 4. Furthermore, a control mechanism for controlling the inert gas in the processing chamber 4 to a predetermined concentration based on the monitoring result may be provided in the electron beam irradiation apparatus.

  As a method for measuring the inert gas concentration in the processing chamber 4, a method for measuring the oxygen concentration with an oximeter instead of measuring the inert gas concentration to be used, a method for directly measuring the inert gas concentration, etc. Usually, an oximeter method is used.

  As an example of the measurement method of the inert gas concentration, a method of using nitrogen as the inert gas and grasping the inert gas concentration using an oxygen concentration meter will be described below. When nitrogen is purged into the processing chamber, nitrogen and oxygen occupy most of the components in the atmosphere, so if the oxygen concentration is measured as 1000 ppm by volume in the oxygen concentration meter, the nitrogen concentration is approximately 99.9% by volume. It can be said that. Further, if there is a large amount of oxygen in the processing chamber 4, it is considered that when the electron beam 5 is irradiated, the oxygen is decomposed and combined by the energy of the electron beam 5 to generate ozone. This ozone promotes oxidative deterioration in the apparatus and may oxidize the outermost surface of the rubber elastic layer 3 in the rubber roller 1, which may reduce performance such as desired hardness of the elastic roller.

  Therefore, in the present invention, from the viewpoint of reducing the influence of the change in the inert gas concentration in the processing chamber on the degree of modification of the rubber elastic layer 3 in the rubber roller 1, the oxygen concentration in the processing chamber is set to 1000 ppm by volume or less. It is desirable. Further, the lower the oxygen concentration in the processing chamber, that is, the higher the inert gas concentration, the better.

  Here, the flow rate of the inert gas supplied from the inert gas supply means into the chamber depends on the degree of modification of the outermost surface of the rubber elastic layer 3 and the accuracy of the monitor mechanism 10 that monitors the irradiation state of the electron beam 5. Can be selected as appropriate. The flow rate of the inert gas can be, for example, 20 L / min or more and 100 L / min or less under conditions of room temperature (23 ° C.) and pressure (standard atmospheric pressure 101.325 kPa).

・ Excitation light detection means The excitation light detection means from the inert gas is the real-time excitation light by the electron beam from the inert gas between the object to be processed (area where the object is placed) and the foil. For example, the irradiation state of the electron beam on the rubber elastic layer in the axial direction can be monitored in real time. The electron beam irradiation apparatus shown in FIGS. 2 and 3 includes a light emission intensity distribution monitoring mechanism 10 that monitors the light emission intensity distribution in the electron beam measurement range 15 as the detection means. This electron beam measurement range 15 is set in a space portion between the exit aperture foil 13 of the electron beam 5 and the rubber elastic layer 3 in the rubber roller 1. The length of the electron beam measurement range 15 (the direction perpendicular to the paper surface in FIG. 2) and the short direction (the left-right direction on the paper surface in FIG. 2) and the thickness of the range 15 are applied to the rubber roller 1. It can set suitably according to the irradiation range of the electron beam 5 to be performed. For example, as shown in FIG. 1, the length in the longitudinal direction of the electron beam measurement range 15 may be set to the same length as the axial width of the rubber elastic layer irradiated with the electron beam or longer than that. it can.

  That is, in the monitoring mechanism 10, in the axial direction of the rubber elastic layer, the excitation light of the inert gas by the electron beam is in a range including the entire axial width of the rubber elastic layer irradiated with the electron beam, for example, in the axial direction. It can be detected at a length of 200 to 350 mm. Thereby, the irradiation state of the electron beam on the rubber elastic layer in the axial direction, specifically, the electron dose irradiated to the rubber roller 1, for example, the light emission intensity distribution (luminance in the axial direction of the rubber elastic layer). Distribution) can be observed in-line in real time. Note that observing (monitoring) the irradiation state of the electron beam in-line means automatically observing the irradiation state of the electron beam during the manufacturing process (on the way), and if necessary, the result is real-time in the manufacturing operation. You can give feedback. With this in-line monitoring mechanism, the irradiation state of the electron beam can be observed constantly, periodically, or intermittently.

  As shown in FIGS. 2 and 3, the monitor mechanism 10 can be disposed, for example, on the conveyance direction side (right side of the sheet) of the rubber roller 1.

<Method for producing elastic roller>
According to the present invention, there is provided a method for producing an elastic roller having a surface-modified rubber elastic layer, wherein an electron beam source is applied to a region of a predetermined width in the axial direction of the rubber elastic layer on the surface of the rubber elastic layer of the rubber roller. It has the process (electron beam irradiation process) which irradiates an electron beam through the foil which can permeate | transmit this electron beam.
In this step, the electron beam is simultaneously applied to the entire axial width of the rubber elastic layer on the surface of the rubber elastic layer in an inert gas atmosphere between the surface of the rubber elastic layer of the rubber roller and the foil. The excitation light is generated from the inert gas with a predetermined width in the axial direction of the rubber elastic layer, and the intensity distribution of the excitation light with a predetermined width in the axial direction of the rubber elastic layer To monitor.

  Moreover, in this invention, you may have the process of feeding back the monitoring result of intensity distribution to the irradiation conditions of an electron beam.

  Below, the manufacturing method of this invention is demonstrated in detail using figures.

(Production process of surface-modified rubber roller)
The rubber roller 1 having the rubber elastic layer 3 around the core metal 2 (in FIG. 1, the outer peripheral surface of the core metal 2) forms a rubber elastic layer on the outer periphery of the core metal 2 by a known molding method, for example. The rubber elastic layer can be produced by heating and polishing. The molding method of the rubber roller is not particularly limited, and for example, injection molding, extrusion molding, transfer molding, press molding, or the like can be used. The method for heating the rubber roller is not particularly limited, and any method such as a hot air furnace, a vulcanizing can, a hot platen, far / near infrared rays, induction heating, etc. may be used. A method may be used in which the rubber elastic layer is pressed against the shaped member while rotating. Moreover, in order to make the obtained rubber roller into a desired roller shape and roller surface roughness, dry polishing using a rotating grindstone may be performed on the rubber roller. The polishing means is not particularly limited, and there is a so-called traverse method in which a grindstone moves and polishes, and a plunge method in which lump polishing is performed without moving by a wider grindstone.

(Process a: Electron beam irradiation and inert gas excitation process)
On the surface of the rubber elastic layer 3 of the rubber roller 1 obtained as described above, a region having a predetermined width required for the surface hardening treatment in the axial direction of the rubber elastic layer, for example, the total width of the rubber elastic layer in the axial direction, The electron beam 5 generated from the electron beam source is irradiated through the foil (emission port foil 13). The rubber elastic layer 3 is subjected to surface modification by irradiation with this electron beam. In the present invention, at this time, the surface of the rubber elastic layer 3 is irradiated with an electron beam in an inert gas atmosphere between the surface of the rubber elastic layer 3 and the exit aperture foil 13, and the surface of the rubber elastic layer is exposed. While performing modification, excitation light is generated from an inert gas between the rubber elastic layer and the foil. By irradiating the entire surface (specifically, the outer peripheral surface) of the rubber elastic layer with an electron beam, the target surface modification of the rubber elastic layer can be performed. At that time, the entire surface of the rubber elastic layer may be irradiated with an electron beam at the same time. As shown in FIGS. 1 to 3, a part of the rubber elastic layer in the circumferential direction and the entire width in the axial direction of the rubber elastic layer may be used. You may irradiate an electron beam to the whole surface of a rubber elastic layer by rotating a rubber roller, irradiating an electron beam. Further, the surface modification of the rubber elastic layer may extend from the surface of the rubber elastic layer to the vicinity thereof.

  In the electron beam irradiation apparatus shown in FIG. 2 and FIG. 3, first, the filament 11 is heated through current by a power source (not shown), thermionic electrons are emitted from the filament, and are effectively taken out as the electron beam 5. Then, after accelerating in the accelerating space in the accelerating tube 12 kept in a vacuum state by the acceleration voltage of the electron beam 5, the electron beam is emitted from the electron beam generator 14, penetrates (permeates) the exit aperture foil 13, and exits the exit aperture. The rubber roller 1 conveyed in the processing chamber 4 below 8 is irradiated. As a result, the rubber elastic layer 3 of the rubber roller 1 is hardened and the inert gas supplied by the inert gas supply mechanism 9 generates excitation light by the electron beam 5.

  The irradiation condition of the electron beam 5 can be adjusted by the acceleration voltage and dose of the electron beam 5. The acceleration voltage of the electron beam is related to the surface hardening depth of the rubber elastic layer 3, and the acceleration voltage condition in the present invention is preferably in the range of 40 kV to 300 kV, which is a low energy region. If it is 40 kV or more, sufficient cured thickness for easily obtaining the effects of the present invention can be obtained. Moreover, if it is 300 kV or less, it can suppress easily that an electron beam irradiation apparatus enlarges and an apparatus cost increases. More preferable conditions for the acceleration voltage of the electron beam are in the range of 70 kV to 150 kV.

The dose of the electron beam 5 in electron beam irradiation can be defined by the following formula (1).
D = (KI) / V (1)
Here, D is a dose (kGy), K is an apparatus constant, I is an electron current (mA), and V is a conveyance speed (m / min). The device constant K is a constant representing the efficiency of each device, and is an index of device performance. The device constant K can be obtained by measuring the dose by changing the electron current and the transport speed under the condition of a constant acceleration voltage.

  The dose of the electron beam 5 can be appropriately selected according to the desired hardness of the rubber elastic layer surface of the elastic roller. The adjustment of the electron dose can be performed by either the electron current or the processing speed, and may be determined so as to obtain a desired dose. The electron dose is preferably 100 kGy or more and 5000 kGy or less from the viewpoint of the performance of the rubber roller, for example, the surface hardness. It should be noted that the effect of the present invention can be further recognized if the electron dose is in the range of more than 200 kGy and less than or equal to 5000 kGy, which has been difficult with the conventional electron dose measurement method.

(Process b: Monitor process)
In step b, the excitation light in the electron beam measurement range 15 above the rubber elastic layer 3 of the rubber roller 1 is measured by the monitor mechanism 10 across the axial direction of the rubber roller 1. The monitor mechanism 10 has a configuration for measuring the emission intensity distribution of the excitation light in the axial direction of the rubber elastic layer. In the monitor mechanism 10, for example, a monochrome or color CCD camera can be used as the light receiving unit for observing or measuring the emission intensity. By converting the measured emission intensity distribution into an electron dose distribution, the electron dose irradiated to the rubber roller 1 and the electron dose distribution (unevenness) in the axial direction of the rubber roller 1 can be monitored.

  Here, as a monitoring method, for example, a method of periodically measuring an electron dose distribution of a rubber roller in real time, a method of acquiring an image only once per rubber roller and measuring an electron dose distribution in real time, and a rubber roller A method of always measuring the electron dose distribution in real time in real time can be mentioned. From these monitoring methods, a monitoring method suitable for the intended quality control method and the like can be selected and used. Among these, in the present invention, a method of constantly measuring the electron dose distribution of the rubber roller in real time is effective, whereby the electron dose distribution can be measured in real time for all the outer peripheral surfaces of the rubber elastic layer of the rubber roller. If this electron dose distribution is always measured in real time, it is possible to immediately cope with a sudden abnormality, for example, when an electron beam stops due to filament deterioration. According to this method, since there is no non-measurement period, compared to the method of periodically measuring the electron dose distribution with the interval described above, for example, all the rubber rollers are directly irradiated with the electron beam. Can be confirmed. Further, if this electron dose distribution is always measured in real time, there is no non-measurement period as compared with the method of acquiring one image per rubber roller, so that irradiation failure occurs in all rubber rollers. And the presence or absence of uneven electron dose in the circumferential direction within one elastic roller.

  Examples of a method for deriving a conversion formula for converting luminescence intensity into an electron dose include a method using a film-type dosimeter and a method using a calorimeter derived from a change in heat.

  Hereinafter, an example of a method for converting the emission intensity (luminance) distribution detected by the detection means into an electron beam dose distribution will be described with reference to FIG. In addition, in FIG. 5, although the flat plate-shaped dosimetry film 16 is described, this film 16 is stuck and used for the outer peripheral surface of a rubber roller. As the film-type dosimeter, a trade name “FWT-60” (manufactured by Far West Technology), which is generally used in the field of electron beams, can be used. At this time, the film-type dosimeter tends to be difficult to obtain high measurement accuracy due to various factors including the influence of the variation in film thickness. Therefore, measurement accuracy can be improved by measuring the thickness of the film to be used in advance. For example, further measurement accuracy can be achieved by measuring the thickness distribution of the film in advance and selecting and using a sheet having a thickness distribution of 10 μm ± 2 μm.

  Specifically, the electron beam 5 generated from the electron beam source (filament 11) is irradiated on the outer peripheral surface of the rubber roller to which the film 16 whose thickness has been measured is attached. Then, after irradiating the electron beam 5, the film 16 that absorbed the energy of the electron beam 5 is aged for 5 to 10 minutes until the degree of coloration is stabilized, and the color density of the film is measured by a measuring device (trade name: FWT not shown). -92D, manufactured by Far West Technology). Thereby, the relationship between the value of the electron current set on the electron beam irradiation device side to be used and the electron dose irradiated to the film can be derived. Furthermore, the value of the electron current set on the electron irradiation device side is changed, and the corresponding electron dose irradiated to the film is obtained. As described above, this film-type dosimeter has a measurable electron dose range of 200 kGy or less, but the electron current set on the electron beam irradiation device side, the electron dose irradiated on the film, and This relationship holds even when the electron dose exceeds 200 kGy. For this reason, from the derived relationship, an electron current value that falls within a desired dose range (for example, 500 kGy or more and 5000 kGy or less) used for the surface curing of the rubber roller in the present invention can be calculated.

  Next, based on the relationship between the electron current and the electron dose at the initial stage of the electron beam irradiation apparatus guided by the above method, the emission intensity of the inert gas when the rubber beam is irradiated with the electron beam 5 is observed by a monitor mechanism. At that time, for example, nitrogen is supplied as an inert gas, and the oxygen concentration in the processing chamber is set to 200 ppm by volume, for example. And after confirming that the inert gas density | concentration in a process chamber was stabilized, an electron beam is irradiated to a rubber elastic layer, and the average value of the emitted light intensity in the axial direction of a rubber roller is calculated. And by using this average value, the relationship between the electron dose obtained using the above-mentioned film corresponding to the value of the electron current set on the used electron beam irradiation apparatus side and the emission intensity is derived. Can do. At that time, in parallel with the observation (measurement) by the monitor mechanism, it is preferable to measure the hardness of the rubber elastic layer of the rubber roller irradiated with the electron beam at three points (both ends and the center) in the axial direction. Based on the result of this hardness measurement, the distribution of light emission intensity in the axial direction of the rubber roller, that is, the electron dose distribution is set so that the surface of the rubber elastic layer has the desired hardness as an elastic roller for electrophotography. It is preferable to keep it.

  The uniformity of surface modification in the elastic roller can be evaluated by measuring the hardness distribution on the surface of the rubber elastic layer of the obtained elastic roller. An MD-1 hardness meter can be mentioned as an example of an apparatus for measuring the surface hardness. The MD-1 hardness tester is a micro rubber hardness tester, in which the needle is pressed against the surface of the sample by the force of the spring to cause deformation, and the needle push-in depth in a state where the resistance of the sample and the force of the spring are stabilized. It is a device that measures the thickness.

  Here, since the intensity of the excitation light generated from the inert gas depends on the inert gas concentration, the slit is arranged in parallel to the axial direction of the rubber elastic layer and has a length equal to or greater than the axial width of the rubber elastic layer. It is more preferable to use the electron beam irradiation apparatus shown in FIG. 3 having a gas supply port having a shape. That is, according to the electron beam irradiation apparatus having the structure shown in FIG. 3, the concentration change of the inert gas in the electron beam measurement range 15 is small, and the electron dose irradiated to the rubber elastic layer 3 of the rubber roller 1 is increased in the axial direction of the rubber roller. It is possible to monitor constantly with high accuracy. Therefore, it is possible to stably and easily manufacture a high-quality elastic roller having a uniform degree of modification by an electron beam in the axial direction of the rubber roller and a small change in the hardness of the roller over the course of manufacturing.

  As described above, in the present invention, the electron dose distribution irradiated to the axial direction of the rubber elastic layer 3 of the rubber roller 1 measured by the monitor mechanism 10 can be measured in real time at all times. It is possible to easily determine the state of the electron beam irradiation apparatus, such as the presence or absence of irradiation and the decrease in electron dose due to filament degradation.

  Furthermore, by feeding back these measurement results to the electron beam irradiation apparatus, it is possible to control the electron dose irradiated to the rubber roller 1 so that it is stabilized. For example, as the electron beam irradiation device, a device having a configuration in which a large number of filaments are arranged in parallel, or a device having a configuration for scanning an electron beam generated by a single filament can be used. In the electron beam irradiation apparatus having such a configuration, a control system of the electron beam irradiation apparatus that instructs to perform irradiation without electron dose unevenness when detecting a decrease in electron dose or an electron dose unevenness in the axial direction of the elastic roller. In addition, feedback control of electron dose can be performed. As this feedback control method, one or a combination of two or more methods capable of performing the desired feedback control, such as a method of increasing the electron current input to the filament and a method of slowing the roller conveyance speed, are used. be able to. Thereby, it becomes possible to reduce the surface modification unevenness of the elastic roller resulting from the decrease of the electron dose accompanying the deterioration of the filament. However, since the conveyance speed of the elastic roller directly affects the production tact, it is preferable to control the electron dose based on the value of the electron current input to the filament. In addition, if the electron dose suddenly becomes abnormal, such as the life of the filament, it may be possible to stop the apparatus, which reduces the variation in the degree of modification by the electron beam in the axial direction of the rubber roller for electrophotography. It is possible to stably manufacture a high-quality elastic roller.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not limited to these.

[Example 1]
First, an electron is applied to a rubber roller in which a rubber elastic layer having a thickness of 1.25 mm is disposed on the outer peripheral surface of a stainless steel core having an outer diameter of 5 mm and a length of 250 mm, with both ends of the core being left at 11 mm. The surface was hardened with a wire.

  An electron beam irradiation apparatus (trade name: “EC150 / 45/40 mA”, manufactured by Iwasaki Electric Co., Ltd.) shown in FIG. 3 was used for irradiation of the rubber roller with an electron beam. This electron beam irradiation apparatus has, as the inert gas supply mechanism 9, two slit-shaped gas supply ports at a position directly opposite to the electron beam emission port at a position facing the rubber elastic layer in the axial direction. Yes. The electron beam irradiation conditions were an acceleration voltage of 80 kV, an electron current of 40 mA, and a rubber roller conveyance speed of 10 mm / s, whereby the electron beam dose was 1350 kGy. At this time, nitrogen gas that emits light in the blue to ultraviolet region by an electron beam in the processing chamber is supplied from the gas supply port at a flow rate = 20 L / min (temperature 23 ° C., pressure (value at standard atmospheric pressure 101.325 kPa)). At that time, the value of the oxygen concentration by the oximeter was substituted for the nitrogen gas concentration, and the oxygen concentration was set to 500 ppm by volume, that is, the nitrogen gas concentration was about 99.95% by volume.

  Then, both ends of the rubber roller are held by holding shafts and rotated at a rotation speed of 100 rpm, and the entire width in the axial direction of the rubber elastic layer is irradiated through the exit aperture foil, and the entire surface of the rubber elastic layer is irradiated with electrons. Modification by wire was performed. Then, the rubber roller is transported at the transport speed, and simultaneously with the electron beam irradiation, a color CCD camera is used as a monitor mechanism to emit light of nitrogen (excitation light) by the action of the electron beam along the axial direction of the rubber elastic layer in the rubber roller. The intensity distribution was measured. The observation range at that time was 228 mm along the axial direction of the rubber elastic layer, and the length (distance) in the radial direction from the central axis of the cored bar was 3.75 mm or more and 4.25 mm or less. The emission intensity distribution measured by the color CCD camera is converted into an electron dose distribution by a conversion method using a value calculated by a film type dosimeter having a predetermined film thickness distribution accuracy described in the above embodiment. Converted. Here, 1000 elastic rollers are manufactured while in-line monitoring is performed by the monitor mechanism, that is, during the operation of the manufacturing apparatus, and the electron dose applied to the rubber roller is controlled by adjusting the electronic current input to the filament. did.

(Evaluation of surface modification uniformity)
Each of the obtained 1,000 elastic rollers was left in an environment of room temperature 23 ° C. and relative humidity 45% for one day, and then the hardness of the rubber elastic layer surface in the axial direction of each elastic roller was measured. At that time, for each elastic roller, the average value of four points measured at equal intervals in the circumferential direction is taken as the hardness at a certain point in the axial direction of each elastic roller, and measured at intervals of 20 mm in the axial direction from the end of the rubber elastic layer. Ten points were measured (that is, a total of 40 points of hardness were measured for each elastic roller). For the measurement of hardness, an MD-1 hardness meter (trade name: micro rubber hardness meter MD-1 type, Type A, manufactured by Polymer Design Co., Ltd.) was used.

  Specifically, the average hardness of 100 elastic rollers out of the 1000 obtained, that is, the average value of the hardness measurement value (40 points) of each elastic roller × the number of elastic rollers (100) is obtained as a reference. Hardness. In the case of Example 1, the reference hardness was 73 °. The 40 hardness measurement positions are provided in the circumferential direction of the rubber roller at four measurement positions at intervals according to the measurement purpose, and the circumferential four-point measurement position is set in the axial direction of the rubber roller according to the measurement purpose. It was set by taking 10 points at intervals.

  Moreover, the hardness average value of 40 points | pieces in each elastic roller was compared about 1000 elastic rollers, the dispersion | variation in the hardness average value was computed, and production stability was evaluated.

  Furthermore, according to the criteria shown in Table 1 below, the uniformity of the modification degree was evaluated for the 1000 elastic rollers. These results are shown in Table 2.

  As a result of performing the above hardness measurement on the total number of 1000 elastic rollers manufactured in Example 1, the variation in the hardness of the elastic roller in the axial direction is small and stable compared to Comparative Example 1 using a film-type dosimeter. I was able to confirm.

  As described above, since the electron dose distribution irradiated along the axial direction of the rubber roller guided by the monitor mechanism 10 can always be measured in real time, for example, the presence or absence of electron beam irradiation or the decrease in electron dose due to filament degradation. It is also possible to judge. Then, by feeding back these measurement results to the electron beam irradiation device, the amount of electrons irradiated to the rubber roller is controlled to be stable, and the elastic roller has a small variation in hardness in the axial direction and is a high quality elastic roller. Can be manufactured stably.

[Example 2]
An elastic roller was produced in the same manner as in Example 1 except that the electron beam irradiation condition was an acceleration voltage of 80 kV, the electron current was 20 mA, and the rubber roller conveyance speed was 10 mm / s, so that the electron beam dose was 675 kGy. evaluated. The average hardness (reference hardness) of 100 elastic rollers out of 1000 obtained in Example 2 was 71.5 °. These results are shown in Table 2.

Example 3
An elastic roller is manufactured in the same manner as in Example 1 except that the electron beam irradiation conditions are an acceleration voltage of 80 kV, an electron current of 40 mA, and a rubber roller conveyance speed of 2.5 mm / s to set the electron beam dose to 5400 kGy. And evaluated. The average hardness (reference hardness) of 100 elastic rollers out of 1000 obtained in Example 3 was 80 °. These results are shown in Table 2.

Example 4
The flow rate of nitrogen gas supplied into the processing chamber of the electron beam irradiation apparatus is 20 L / min (temperature 23 ° C., pressure (standard atmospheric pressure 101.325 kPa)), and the oxygen concentration in the processing chamber is 1000 ppm by volume (that is, nitrogen An elastic roller was manufactured and evaluated in the same manner as in Example 1 except that the gas concentration was about 99.9% by volume. The average hardness (reference hardness) of 100 elastic rollers out of 1000 obtained in Example 4 was 73 ° as in Example 1. These results are shown in Table 2.

Example 5
The flow rate of nitrogen gas supplied into the processing chamber of the electron beam irradiation apparatus is 20 L / min (value at a temperature of 23 ° C. and a standard atmospheric pressure of 101.325 kPa), and the oxygen concentration in the processing chamber is 2000 ppm by volume, that is, the nitrogen gas concentration An elastic roller was produced and evaluated in the same manner as in Example 1 except that the amount was about 99.8% by volume. The average hardness (reference hardness) of 100 elastic rollers out of 1000 obtained in Example 5 was 73 °, as in Example 1. These results are shown in Table 2.

Example 6
Neon gas is used as an inert gas that emits light by an electron beam, this neon gas is supplied into the processing chamber at 20 L / min, and the oxygen concentration in the processing chamber is set to 500 ppm by volume, so that the neon gas concentration is about 99.95 volumes. %. In addition, a color CCD camera capable of observing the entire rubber roller was used as a monitor mechanism. Except for these, an elastic roller was produced in the same manner as in Example 1. The average hardness (reference hardness) of 100 elastic rollers out of 1000 obtained in Example 6 was 73 °. These results are shown in Table 2.
Neon gas emits light in the red region by an electron beam. Therefore, a sufficient luminance change can be acquired in the used CCD camera.

Example 7
In order to improve the influence on the elastic roller due to the nitrogen concentration change in the processing chamber and the observation accuracy by the monitor mechanism, the electron beam irradiation apparatus shown in FIG. 3 having the following inert gas supply mechanism is used and supplied to the processing chamber. The flow rate of nitrogen gas was 20 L / min, and the oxygen concentration in the processing chamber was 200 ppm by volume (that is, the nitrogen gas concentration was about 99.98 volume%). Except for these, an elastic roller was produced in the same manner as in Example 1. The average hardness (reference hardness) of 100 elastic rollers out of 1000 obtained in Example 7 was 73 ° as in Example 1. These results are shown in Table 2.

  The inert gas supply mechanism 9 of the electron beam irradiation apparatus used in Example 7 has a slit-shaped gas supply port having a length of 228 mm, which is the same as the axial width of the rubber elastic layer in the rubber roller, parallel to the axial direction of the rubber elastic layer. 2 places. The two gas supply ports are arranged at positions directly below the electron beam emission port and opposed to each other with the electron beam generated from the electron beam source interposed therebetween. When the electron beam treatment is performed on the rubber roller by this electron beam irradiation device, the nitrogen gas supplied from the two slits (gas supply ports) is directed toward the rubber elastic layer surface immediately after jetting as shown in FIG. It will be a downward flow. For this reason, in this electron beam irradiation apparatus, the fluctuation | variation of an inert gas concentration becomes very small in the measurement range by a monitor mechanism.

Here, the axial light emission intensity distribution of an example of the rubber roller manufactured in Examples 1 to 6 is shown in FIG. 4B, and the axial light emission intensity distribution of an example of the rubber roller manufactured in Example 7 is shown in FIG. c). In these graphs, the horizontal axis (x-axis) represents the position (for example, d ₀ or d ₁ ) in the axial direction of the rubber roller, and the vertical axis (y-axis) represents the emission intensity. From these graphs, it can be seen that the use of the inert gas supply means used in Example 7 can reduce the emission intensity fluctuation, that is, the inert gas concentration fluctuation.

  FIG. 4D shows a time-series change of an example of light emission intensity (light emission luminance) at the location a in the measurement range 15 in the monitoring mechanism shown in FIG. From FIG. 4D, it can be seen that the emission intensity fluctuation, that is, the inert gas density fluctuation can be suppressed over time.

[Comparative Example 1]
In the electron beam irradiation apparatus used in Example 1, the electron irradiated on the rubber roller 1 by the dosimetry method using the dosimetry film 16 colored by the energy by the electron beam irradiation shown in FIG. Dose was measured. Then, it was confirmed that this method can stably produce an elastic roller having no variation in hardness distribution in the axial direction. Specifically, instead of the monitoring mechanism of the first embodiment, a film-type dosimeter is used at a rate of once every 100 pieces, and the electron beam irradiation device is adjusted each time so that the axial direction of the elastic roller is adjusted. It was confirmed how much variation occurred in the hardness. The results are shown in Table 2. The electron dose measurement method is a method in which a film-type dosimeter is attached to the surface of the rubber roller 1 as shown in FIG. 6, with two pieces in the circumferential direction of the rubber roller and five pieces in the axial direction (the number shown in FIG. 6). (Different) Affixed and rotated at a rotational speed of 100 rpm to perform electron beam irradiation. And based on the measured electron dose, the electron dose was adjusted by operating an electron current so that it might become the set electron dose. The electron dose for producing the elastic roller is 1350 kGy, as in Example 1, but the measurable electron dose range of the film-type dosimeter is 200 kGy or less, so the measurement with the film-type dosimeter is performed. In this case, the electron beam irradiation conditions were an acceleration voltage of 80 kV, an electron current of 5 mA, and a conveyance speed of 10 mm / s, so that the electron dose applied to the rubber roller was 168 kGy. And the obtained result was converted into 1350 kGy which is the electron dose of Example 1, and the electron beam irradiation apparatus was adjusted based on it. As a result, it was necessary to adjust the electron beam irradiation apparatus in the range of 40 mA ± 2 mA of electron current due to variations in the electron dose value of the film type dosimeter due to film thickness, conversion error, and the like. As a result, as shown in Table 2, the measurement was performed on a total of 1000 manufactured elastic rollers.
As described above, when using a film-type dosimeter, not only the variation in measurement is large, but also time is required from irradiation and development to digitization, and the electron dose cannot be calculated immediately. I think it is difficult to apply to the purpose.

  On the other hand, in Examples 1 to 7, high-quality elastic rollers having uniform and stable hardness in the axial direction could be obtained.

  As described above, according to the present invention, an elastic roller that can stably manufacture a high-quality elastic roller in a simpler manufacturing process with less unevenness of modification by the electron beam 5 in the axial direction of the rubber elastic layer 3 in the rubber roller 1. It was confirmed that a manufacturing method can be provided.

  The variation of the average hardness value in Table 2 is shown as the maximum value of the deflection in both directions of the hardness at each measurement point with respect to the average of all the measured hardnesses in each elastic roller. Further, the hardness variation in the axial direction is shown as the maximum value of the deflection in both directions of ± of the hardness at each measurement point with respect to the average of all the measured hardnesses at 10 measurement positions in the axial direction.

1 ... Rubber roller (roller before electron beam irradiation)
DESCRIPTION OF SYMBOLS 2 ... Metal core 3 ... Rubber elastic layer 4 ... Processing chamber 5 ... Electron beam 6 ... Holding shaft 7 ... Rotating mechanism 8 ... Outlet 9 ... Inert gas Supply mechanism 10. Monitor mechanism 11. Filament 12. Accelerator tube 13. Outlet foil 14. Electron beam generator 15. Electron beam measurement range 16. Dose measurement film

Claims (4)

A method for producing an elastic roller comprising a core metal and a rubber elastic layer formed around the core metal, the surface of the rubber elastic layer being cured by an electron beam ,
Of the surface of the rubber elastic layer covering around the metal core, with respect to the axial direction of the full width of the metal core, the electron beam from the electron beam source through the permeable foil electron beam, irradiation An electron beam irradiation process to radiate,
The electron beam irradiation step includes
By irradiating the electron beam between the surface of the rubber elastic layer and the foil in a nitrogen gas atmosphere having an oxygen concentration of 1000 ppm by volume or less, the surface of the rubber elastic layer and the foil excitation light from the nitrogen gas in the space portion between generated in total width in the axial direction of the rubber elastic layer,
By monitoring the excitation light in the space portion between the surface of the rubber elastic layer and the foil with a CCD camera over a range including the entire width of the rubber elastic layer in the axial direction, A method for producing an elastic roller, comprising a step of observing an irradiation state of an electron beam on the surface of the rubber elastic layer over the entire width in the axial direction . In the electron beam irradiation step, a slit-shaped gas supply port having a length greater than or equal to a predetermined width in the axial direction of the rubber elastic layer is arranged to face the elastic roller so as to be parallel to the axial direction. The method for producing an elastic roller according to claim 1, further comprising a step of making a nitrogen gas atmosphere between the foil and the rubber elastic layer by ejecting nitrogen gas from the slit-shaped gas supply port.   The elastic roller manufacturing method according to claim 1 or 2, wherein feedback control of electron dose in the electron beam irradiation step is performed based on an observation result of the irradiation state of the electron beam.   The method of manufacturing an elastic roller according to any one of claims 1 to 3, wherein the electron beam source includes a plurality of filaments arranged in parallel.

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