JP2006082495A - Manufacturing apparatus of coating tube for charging member, charging member, cartridge for electrophotographic device, and electrophotographic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a charging member in which a seamless tube coating an elastic body layer is approximately straight in the lengthwise direction and further unevenness of an outer diameter is controlled, and to provide a manufacturing apparatus of a coating tube for the charging member preventing vibration generated by a cutting mechanism in the manufacturing process. <P>SOLUTION: The manufacturing apparatus of the coating tube for the charging member which has a mechanism of extruding a tube in the direction of gravity, an air-cooling mechanism, a water-cooling sizing mechanism, a take-up mechanism of the tube and a cutting mechanism of the tube to coat the elastic body on a core metal with the seamless tube is characterized in that it has one or more contact type cutting vibration preventing mechanisms in contact with the tube in back of the water-cooling sizing mechanism. By this it is possible to achieve that the straightness of the coating tube is not more than 1 mm, and that a ratio (Δ/Da×100), by percentage, of difference between the maximum value and the minimum value of the average value of outer diameters to the average value Da of all measured values of the outer diameters is not more than 0.2%, the outer diameters being measured at 3 or more positions in the circumferential direction at each of 5 or more positions in the lengthwise directions. The charging member is obtained by the apparatus. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a charging member that is placed in contact with a member to be charged and charges the member to be charged by applying a voltage, and a method for manufacturing the coated tube. The present invention also relates to an electrophotographic cartridge having the charging member and an electrophotographic apparatus.

  In recent years, a contact charging type charging unit has been adopted as a charging unit used in an image forming apparatus such as an electrophotographic apparatus or an electrostatic recording apparatus. Contact charging is to charge a charged body to a predetermined polarity and potential by applying a voltage to a charging member placed in contact with the charged body, and the voltage of a power source can be lowered, such as ozone. There are advantages that the generation of corona products can be reduced, the structure is simple, and the cost can be reduced.

  The voltage applied to the charging member has a peak-to-peak voltage that is at least twice the charging start voltage of the object to be charged when a DC voltage is applied to the contact charging member, in addition to a method in which only DC is applied (DC application method). There is a technique (AC application method) in which an oscillating electric field (electric field whose voltage value changes periodically with time) is formed between the contact charging member and the object to be charged, and the surface of the object to be charged is charged (AC application method). Can be charged easily.

  In addition, the contact charging device is a roller-type charger using a charging member as a roller-like member (charging roller) or a blade-type charging using a blade-like member (charging blade) according to the shape and form of the charging member brought into contact with an object to be charged. And a brush-type charger or the like, which is a charger and a brush-like member (charging brush) (see, for example, Patent Documents 1 to 4).

  The charging roller is rotatably supported by the bearing, is brought into pressure contact with the member to be charged at a predetermined pressure, and rotates as the member to be charged moves.

  The charging roller is usually a multilayer structure having a cored bar provided at the center as a base, a conductive elastic layer provided in a roller shape on the outer periphery of the cored bar, and a surface layer provided on the outer periphery thereof. .

  Among the above layers, the cored bar (metal layer) is a rigid body for maintaining the shape of the roller, and has a role as a feeding electrode.

In addition, the elastic layer usually has a volume resistivity of 10 ⁴ to 10 ⁹ Ω · cm, and a function to ensure uniform contact with the member to be charged by elastic deformation. A vulcanized rubber having a softness of 70 degrees or less with a rubber hardness (JIS A) imparted with conductivity is used. Conventional charging rollers include a foam type that uses a rubber foam (or sponge-like rubber) as an elastic layer and a solid type that does not use a rubber foam. The surface layer improves the charging uniformity of the object to be charged, prevents the occurrence of leaks due to pinholes on the surface of the object to be charged, and prevents the adhesion of toner particles, paper powder, etc. Has a function of preventing bleeding of softeners such as oil and plasticizer used to reduce the hardness of the elastic layer. The volume resistivity of the surface layer is usually 10 ⁵ to 10 ¹³ Ω · cm, and conventionally formed by applying a conductive paint or coating a seamless tube (see, for example, Patent Document 5). ).

  The seamless tube manufacturing apparatus produces the seamless tube in the order of an air cooling mechanism, a water cooling sizing mechanism, a tube take-up mechanism, and a tube cutting mechanism by an extruding mechanism. There is a problem that the tube is bent before the water-cooled sizing, or the tube is bent or has a slight difference in the outer diameter of the tube (pulsation occurs).

  It has been found that when the tube take-up mechanism is changed from a belt type to a roller type, the take-up accuracy is improved (see, for example, Patent Document 6). However, when a roller type take-up machine is used, there is a concern that vibrations are more easily transmitted because the number of contacts with the tube is reduced.

  Further, when the tube is thin, the vibration is more easily transmitted as the diameter becomes larger, and the straightness of the tube tends to be worsened.

  The bending and the subtle size of the outer diameter of the seamless tube in use affect the performance of the charging roller after coating. That is, resistance unevenness is mainly generated, and as a result, it is recognized as image unevenness.

  The slightly different outer diameter in the longitudinal direction of the seamless tube to be coated suggests uneven thickness. When this is coated, the uneven thickness of the seamless tube is affected by a difference in tightness in the case of the soft foamed elastic layer underneath.

  Further, when the seamless tube that is bent and taken up is covered, the roller influences according to the bending.

It was thought that this occurred because the roller shape after the coating exhibited the low straightness of the seamless tube, and the level was recognized under the process conditions used.
JP 56-91253 A JP-A 64-24264 JP 56-194349 A JP-A 64-24264 Japanese Patent Laid-Open No. 11-125952 JP 2003-71902 A

  An object of the present invention is to provide a charging member in which the longitudinal shape of a seamless tube coated on an elastic body layer is almost straight and further suppresses uneven outer diameter, and is generated by a cutting mechanism in the coated tube manufacturing process. An object of the present invention is to provide a coated member manufacturing apparatus for a charging member that solves the problem of straightness of the seamless tube by suppressing vibration, and to provide an electrophotographic apparatus cartridge and an electrophotographic apparatus equipped with the apparatus.

In accordance with the present invention, a charging member in which an elastic body on the outer periphery of a metal core is coated with a plurality of seamless tubes, having a mechanism for extruding a tube in the direction of gravity, an air cooling mechanism, a water cooling sizing mechanism, a tube take-up mechanism, and a tube cutting mechanism. In the coated tube manufacturing apparatus for charging member,
After having the water-cooled sizing mechanism, it has a contact-type cutting vibration suppressing mechanism that contacts at least one of the tubes, so that the straightness of the charging member-coated tube is 1 mm or less and at least five outer diameters in the longitudinal direction. The difference Δ between the maximum value and the minimum value of the average value of the outer diameters at least at three locations in the circumferential direction at the measurement position is a 100 fraction value (Δ / Da × 100) with respect to the average value Da of all the outer diameter measurement values. An apparatus for producing a coated tube for a charging member, characterized by being made 2% or less, is provided.

  Further, according to the present invention, the charging member used for the charging mechanism of the electrophotographic apparatus is formed by covering the charging member-coated tube obtained by the above-described charging member-coated tube manufacturing apparatus with an elastic body formed on a cored bar. A charging member is provided.

  Furthermore, according to the present invention, there are provided a cartridge for an electrophotographic apparatus and an electrophotographic apparatus on which the charging member is mounted.

  According to the present invention, a charging roller is provided in which the longitudinal shape of the seamless tube coated on the elastic body layer is almost straight, and the unevenness of the outer diameter is suppressed, and is generated by a cutting mechanism in the coated tube manufacturing process. A charging member-coated tube manufacturing apparatus that solves the problem of straightness of the seamless tube by suppressing vibrations is provided, and an electrophotographic apparatus cartridge and an electrophotographic apparatus equipped with the apparatus can be obtained.

  Hereinafter, embodiments of the present invention will be described in more detail.

  FIG. 1 shows an example of a charging roller which is a charging member 1 'according to the present invention, which is used as a charger of an electrophotographic apparatus. This charging roller is provided with a foamed elastic body layer 2 made of a conductive elastic material on the outer periphery of a core metal 1 made of a highly conductive material such as stainless steel, plated iron, brass and conductive plastic. The outer periphery of the elastic layer 2 is covered with a tubular functional multilayer film 3 (hereinafter, functional multilayer tube). In the case of FIG. 1, the functional multi-layer tube is composed of an inner layer 3 (i) and an outer layer 3 (o).

  As the core metal (metal layer) in the present invention, for example, a good conductor such as aluminum, copper, iron, or an alloy containing these is preferably used. The metal core used in the present invention may be a metal tube having a thickness of about 0.1 to 1.5 mm, or may be a rod shape.

  As the conductive elastic material constituting the foamed elastic body layer 2, a foamed conductive rubber composition or a conductive polyurethane foam containing a conductive material can be used.

  In this case, the rubber component constituting the foamed conductive rubber composition is not particularly limited, but a conductive material is blended with ethylene-propylene-diene rubber (EPDM), chloroprene, chlorosulfonated polyethylene or the like. It is possible to suitably use a foam of a material, a foam of a copolymer rubber of epichlorohydrin and ethylene oxide, or a foam of a conductive rubber blended with a copolymer rubber of epichlorohydrin and ethylene oxide.

Examples of the conductive material blended in these rubber compositions include conductive powders such as carbon black, graphite, metals and various conductive metal oxides (such as tin oxide and titanium oxide), short carbon fibers and metal oxides. Various conductive fibers such as fibers can be used. The blending amount is preferably 3 to 100 parts by weight, particularly preferably 5 to 50 parts by weight with respect to 100 parts by weight of the total rubber component, and thereby the volume resistance of the foamed elastic layer 2 is 10 ¹ to 10 ⁹ Ω. -It is preferable to adjust to about cm. The foamed elastic body layer 2 can be formed by a known vulcanization molding method, and the thickness is appropriately set according to the use of the charging roller, but is usually preferably 1 to 20 mm.

  In the present invention, a functional multilayer film (functional multilayer tube) 3 is coated on the foamed elastic layer 2 in the form of a tube. In this case, the thermoplastic resin and elastomer constituting the functional multi-layer tube 3 may be any extrudable thermoplastic resin or elastomer, specifically, ethylene propylene rubber (EPDM). , Ethylene vinyl acetate, ethylene ethyl acrylate, ethylene methyl acrylate, styrene butadiene rubber, polyester, polyurethane, nylon 6, nylon 66, nylon 11, nylon 12 and other copolymer nylon polyamides, styrene ethylene butyl, ethylene butyl, Ordinary rubber such as nitrile butadiene rubber, chlorosulfonated polyethylene, polysulfide rubber, chlorinated polyethylene, chloroprene rubber, butadiene rubber, 1,2-polybutadiene, isoprene rubber and polynorbornene rubber, steel Down - butadiene - styrene (SBS) and styrene - butadiene - it is possible to use a thermoplastic rubber such as styrene hydrogenated product (SEBS), it is not particularly limited.

  Alternatively, elastomers such as the above-mentioned resins and copolymers and elastomers such as modified products, polyethylene, polypropylene, polyether, polyamide, polycarbonate, polyacetal, polyurethane, polyphenylene oxide, polyvinyl acetate, polyvinylidene fluoride, polytetrafluoro Ethylene; saturated polyesters such as polyethylene terephthalate (PET) and polybutylene terephthalate (PBT); polystyrene, high impact polystyrene (HIPS), acrylonitrile-butadiene-styrene resin (ABS), acrylonitrile-ethylene / propylene rubber-styrene resin (AES) And styrene resins such as acrylonitrile-acrylic rubber-styrene resin (AAS), acrylic resins, vinyl chloride resins, vinyl chloride The combination of materials consisting of the resin and copolymers such as isopropylidene resin.

  Furthermore, a polymer alloy or polymer blend composed of two or more polymers selected from the rubber, thermoplastic elastomer and thermoplastic resin can also be used.

  The resin, elastomer, copolymer, and the like used for the functional multi-layer tube are those described above, and a tube configuration having desired characteristics can be obtained by appropriately blending a conductive material or the like.

  As the conductive material, known materials can be used, for example, carbon fine particles such as carbon black and graphite; metal fine particles such as nickel, silver, aluminum and copper; tin oxide, zinc oxide, titanium oxide, aluminum oxide and silica. Metal oxide fine particles doped with impurity ions with different valences; conductive fibers such as carbon fibers; metal fibers such as stainless steel fibers; the surface of carbon whiskers and potassium titanate whiskers are oxidized metal And conductive whisker such as conductive potassium titanate whisker that has been subjected to a conductive treatment with a material or carbon; and conductive polymer fine particles such as polyaniline or polypyrrole.

  The functional multi-layer tube used in the present invention is formed by extruding a conductive polymer composition comprising the above-mentioned various polymers, the above-mentioned conductive material and, if necessary, other additives.

  Furthermore, in order to obtain a film having a uniform film thickness of each thin film layer of the tube to be formed and a more uniform dispersibility of the conductive material or the like, a vertical tube extruder as shown in FIG. 2 is used in the present invention. use.

  If the functional multi-layer tube used in the present invention is simply molded, it can be obtained by forming a film into a tube by an extrusion molding method, an injection molding method, a blow molding method or the like. For example, for the purpose of obtaining superior durability, environmental resistance, and the like, the seamless tube obtained by the above various molding methods can be further crosslinked to form a conductive crosslinked polymer. As a method of cross-linking the conductive polymer formed into a tube shape, a cross-linking agent such as sulfur, organic peroxide and amines is added in advance according to the kind of the polymer, and the cross-linking is performed at a high temperature. A chemical cross-linking method for generating bismuth, a radiation cross-linking method for cross-linking by irradiating with radiation such as an electron beam or γ-ray is effective. Of the various crosslinking methods described above, the electron beam crosslinking method is preferred because there is no fear of contamination of the charged object due to the migration of the crosslinking agent or its decomposition product, and further, high-temperature treatment is not necessary and safety.

The volume resistance value of the functional multi-layer tube used in the present invention is preferably 10 ⁴ to 10 ¹⁰ Ω · cm, particularly preferably 10 ⁵ to 10 ⁹ Ω · cm.

  Further, in the present invention, the ultra-thin layer tube appropriately function-separated is integrally formed at the same time, so that each layer does not have an unnecessarily thick film, and the foamed elastic body can be used in the entire configuration. It is possible to effectively extract the flexibility of the layer.

  The functional multi-layer tube used in the present invention can be formed by various methods, and the extrusion method is suitable as described above. That is, a compound in which a polymer, a conductive material and, if necessary, a crosslinking agent, a stabilizer and other additives are mixed is manufactured in advance, and the compound is extruded from a die having a ring-shaped slit by an extruder and cooled. Can continuously produce seamless tubes (FIG. 2). A heat-shrinkable tube can be obtained if the tube diameter is expanded during cooling or after cooling and using a means such as air pressurization, and a non-heat-shrinkable tube can be obtained if no expansion treatment is performed.

  The functional multi-layer tube used in the present invention may be either non-heat-shrinkable or heat-shrinkable, but in the examples, a non-heat-shrinkable tube is used.

  In the case of a non-heat-shrinkable tube, the inner diameter of the tube needs to be equal to or less than the outer diameter of the foamed elastic layer in order to ensure the adhesion between the foamed elastic layer and the functional multilayer tube. The external fitting process is completed by inserting a foamed elastic body layer having a core in a state where the tube diameter is expanded by blowing compressed air and releasing the air pressure.

  On the other hand, in the case of a heat-shrinkable tube, the inner diameter of the tube is preferably larger than the outer diameter of the foamed elastic layer. After inserting the foamed elastic layer having a core metal, it is foamed by a method such as heating for a predetermined time in a thermostatic bath. The outer fitting process is completed by thermally shrinking the tube so as to be in close contact with the elastic layer. However, in the case of a heat-shrinkable tube, since the film thickness after shrinkage becomes the final film thickness of the functional multilayer film, an unexpected factor is easily included, and the film thickness and the uniformity of the dispersant are difficult to obtain. Therefore, in consideration of these points, for example, the dispersion conditions are made more stringent, or the application is performed under conditions reflecting the film thickness before and after shrinkage.

  The present invention has a mechanism for extruding a tube in the direction of gravity, an air cooling mechanism, a water cooling sizing mechanism, a tube take-off mechanism, and a tube cutting mechanism, and is charged by covering a plurality of layers of seamless small-diameter thin tubes on an elastic body on the outer periphery of a cored bar. The charging member coated tube manufacturing apparatus as a member is a charging member coated tube manufacturing apparatus having at least one cutting vibration suppressing mechanism after the water cooling sizing mechanism.

  Next, a vertical extrusion apparatus used in the present invention will be described with reference to FIG. The die 4 used for molding is provided with inner and outer double annular extrusion channels 6 and 7 around a central through hole 5 for air introduction, and from the first extruder 8 to the inner channel 6 during molding. The inner layer elastomer composing the functional multi-layer tube and the outer layer elastomer composing the functional multi-layer tube from the second extruder 9 are pressure-injected into the outer flow path 7 respectively, and the inner layer 3 (i ) And the outer layer 3 (o) are integrated and extruded and cooled by a water cooling ring 10 provided on the outer periphery of the functional multi-layer tube 3, which is sent by the tube take-up device 21 to suppress vibrations. It passes through the apparatus 22 and is sequentially cut into a predetermined length, and the foamed elastic layer having the cored bar 1 is coated as a functional multi-layer tube for the charging roller in the next step. The vibration suppressing device 22 in the extrusion device of FIG. 2 shows an example of a device used in the present invention.

  Here, the gist of the technique of the present invention will be described in more detail. In addition to this, the vibration suppressing device 22 may be as shown in FIGS. FIG. 3A shows a two-point contact cylindrical rotating body, and FIG. 3B shows a three-point contact cylindrical rotating body. By means of contact with the tube at least at two points, as shown in FIG. 4, the effect of suppressing vibration due to cutting can be obtained.

  Further, as shown in FIGS. 5A and 5B, the rotating means may be a belt body driven by a spherical rotating body or a plurality of cylindrical rotating bodies. There may be at least one pair of rotating means. In this case, it is preferable that the rotating shaft of the rotating means is orthogonal to the pushing direction of the functional multi-layer tube for the charging roller. For example, if the rotation axis is parallel to the tube extrusion direction, the rotation of the rotation means may apply a force that deviates from the desired positional relationship of the tube extrusion, resulting in an irregular shape in the tube.

  As shown in FIG. 6, the tube outer diameter unevenness is measured by passing the tube through a stainless steel rod having a diameter slightly smaller than the tube diameter, and rotating at the five outer diameter measuring positions in the longitudinal direction of the tube while rotating in the circumferential direction. The 100-percentage value (Δ / Da × 100) of the difference Δ between the maximum value and the minimum value of the average value of the three outer diameters and the average value Da of all the outer diameter measurement values was obtained. As shown in FIG. 7, the tube straightness was measured by measuring the diameter Xa of the end of the tube and the maximum tube bending width Xb perpendicular to the cut surface of the end. When the straightness of the tube is ΔX, ΔX = Xb−Xa.

  When the tube outer diameter unevenness is large, it suggests that the thickness is uneven, and when this is covered, the thickness unevenness of the seamless tube becomes a difference in tightness in the case of the soft foamed elastic layer below it. Resistance unevenness occurs, and as a result, it is recognized as image unevenness.

  Further, when the seamless tube that is bent and taken up is covered, the roller influences according to the bending. That is, the shape of the roller after coating exhibits the low straightness of the seamless tube, which is a level recognized as image unevenness under the process conditions used.

  The difference Δ between the maximum value and the minimum value of the average value of the outer diameter at least at three locations in the circumferential direction at the outer diameter measurement position of at least five locations in the longitudinal direction is equal to or less than 1 mm. When a tube of 0.2% or less is evaluated with a 100-percentage value (Δ / Da × 100) with the average value Da, an image having a much better level of unevenness than the currently applied configuration can be obtained.

  FIG. 8 shows a schematic configuration of an electrophotographic apparatus having a process cartridge having a charging roller of the present invention.

  In FIG. 8, reference numeral 12 denotes an electrophotographic photosensitive member, which is rotationally driven in the direction of the arrow at a predetermined peripheral speed. In the rotation process, a positive or negative predetermined potential is uniformly applied to the peripheral surface by the charging member 1 'according to the present invention. Then, the exposure light 13 is received from exposure means (not shown) such as slit exposure or laser beam scanning exposure. In this way, electrostatic latent images are sequentially formed on the peripheral surface of the photoreceptor 12.

  The formed electrostatic latent image is then developed with toner by the developing unit 14, and the developed toner developed image is rotated between the photoconductor 12 and the transfer unit 15 from a sheet feeding unit (not shown). The images are sequentially transferred by the transfer means 15 to the transfer material 16 that is fed in synchronization.

  The transfer material 16 that has received the image transfer is separated from the photoreceptor surface, introduced into the fixing means 17, and subjected to image fixing, thereby being printed out as a copy (copy).

  The surface of the photoconductor 12 after the image transfer is cleaned by the cleaning means 18 after removal of the transfer residual toner, and is repeatedly used for image formation.

  In the present invention, a plurality of components such as the electrophotographic photosensitive member 12, the charging member 1 ′, the developing unit 14, and the cleaning unit 18 are integrally combined as a process cartridge. It can be configured to be detachable from an electrophotographic apparatus main body such as a copying machine or a laser beam printer. For example, the developing unit 14 and the cleaning unit 18 are integrally supported together with the photosensitive member 12 and the charging member 1 ′ to form a cartridge, and a process cartridge 20 that can be attached to and detached from the apparatus main body using guide means such as a rail 19 of the apparatus main body. can do.

  Further, when the electrophotographic apparatus is a copying machine or a printer, the exposure light 13 is a reflected light or transmitted light from the original, or a signal is read from the original with a sensor, and the laser beam is scanned according to this signal. Light emitted by driving the LED array, driving the liquid crystal shutter array, or the like.

  More specifically, this will be described below with examples and comparative examples.

“When the structure of a functional multi-layer tube is a resistance adjustment layer / conductivity control layer”
The resistance adjusting layer may be a resin whose material itself has an appropriate resistance value, or may be a resin whose resistance value is adjusted by mixing carbon. A multilayer functional tube in which the material of each layer in this example is integrated by simultaneous extrusion can be formed. In the present invention, the tube is formed using a vertical extrusion device. In the horizontal type extrusion device, the flow direction of the extruded tube is arranged perpendicular to the gravity, so that the influence of gravity acts in the circumferential direction of the tube, especially in the hot state immediately after being extruded. Therefore, it was considered that the electrophotographic application used in the present invention lacks definition.

<Core>
The core metal was prepared by extruding an iron material into a bar material having a diameter of about 5 mm by cutting and cutting to a length of 260 mm, and then applying chemical plating to the thickness of about 3 μm.

<Formation of foamed elastic layer>
A vulcanizing agent and a foaming agent are blended with ethylene-propylene-diene rubber (EPDM), and the mixture is formed into a hose shape having an inner diameter of 4.5 mm and an outer diameter of 11.5 mm by an extrusion molding machine, and vulcanized can The foamed elastic body layer foamed inside was cut into a length of 225 mm, and the cored bar having a diameter of 5 mm and a length of 260 mm was inserted into the center hole.

<Formation of functional multi-layer tube>
As a material for the outer layer of the functional multi-layer tube, 100 parts by mass (61.3% by mass) of a styrene-based resin (styrene-ethylene / butylene-olefin copolymer resin, trade name: Dynalon, JSR, melting point 100 ° C.) ), 20 parts by mass of polyethylene (12.3% by mass), trade name: Ketjen Black EC (manufactured by Lion Akzo) 12 parts by mass (7.4% by mass) and trade name: Special Black 250 (Degussa) 20 parts by mass (12.3% by mass), 10 parts by mass of magnesium oxide (6.1% by mass), and 1 part by mass of calcium stearate (0.6% by mass) were mixed in a V-type blender for several minutes. This was further melt-kneaded at 190 ° C. for 10 minutes using a pressure kneader. Furthermore, after cooling, it was pulverized by a pulverizer and pelletized by a single screw extruder.

  As materials for the inner layer, polyurethane elastomer (melting point: 120 ° C.) 100 parts by mass (76.3% by mass), carbon black (trade name: Ketjen Black EC) 20 parts by mass (15.3% by mass), magnesium oxide 10 parts by mass Parts (7.6% by mass) and 1 part by mass (0.8% by mass) of calcium stearate were pelletized in the same process as the material of the outer layer.

Example 1
Using a vertical extruder (special product manufactured by Plastic Giken Co., Ltd., see Fig. 2), the materials of the inner layer and outer layer are merged into a double layer with one crosshead, and the die 4 has a temperature of 155 ° C. Then, the solution was extruded into cold water 10 having an appropriate temperature, cooled further, and then taken out by a tube take-up device. After passing through a pair of driven cylindrical rotating bodies as shown in FIG. 3 (a), the tube was cut with a cutting machine using rotating teeth. In this way, a functional multi-layer tube having an inner diameter of about 12.0 mm was obtained.

(Example 2)
After the tube was taken out in the same procedure as in Example 1, it was passed through a driven three-point contact cylindrical rotating body as shown in FIG. 3 (b), and then the tube was cut with a rotary tooth cutter. In this way, a functional multi-layer tube having an inner diameter of about 12.0 mm was obtained.

(Comparative Example 1)
After the tube was taken up in the same procedure as in Example 1, the tube was cut with a cutting machine using rotating teeth without using the contact-type cutting vibration suppressing mechanism. In this way, a functional multi-layer tube having an inner diameter of about 12.0 mm was obtained.

  The outer diameter unevenness (Δ / Da × 100) and straightness (ΔX) of the obtained functional multi-layer tube were measured. The results are shown in Table 1.

<Production of charging roller>
The outer periphery of the foamed elastic layer was fitted into the foamed elastic layered tube obtained by the above method using a tube coating apparatus (not shown), and pressure-adhered.

  As a result of image formation using this charging roller as a primary charger of an LBP (laser beam printer; laser jet 2-P manufactured by Hewlett Packard), a gap is formed between the functional multi-layer tube 3 and the foamed elastic layer 2. No occurrence of wrinkles, no wrinkles on the functional multi-layer tube 3, and good images without image unevenness were obtained.

  As described above, evaluation by an electrophotographic apparatus using the process cartridge in which the charging members of Examples 1 and 2 and Comparative Example 1 are incorporated is also performed. However, the case according to the present invention is marked as “◎” because it is much better than the currently applied configuration, and the current case is marked as “◯” because it is not a nonconformity.

It is a vertical front view of an example of the charging member of the present invention. It is a vertical front view of an example of the vertical type extruder of the functional multi-layer tube used for this invention. It is a vibration suppression mechanism diagram using a multi-point contact cylindrical rotating body used in the present invention. It is a cutting vibration schematic diagram with and without the contact-type cutting vibration suppressing mechanism of the present invention. It is a vibration suppression mechanism diagram using a belt body driven by a spherical rotating body or a plurality of cylindrical rotating bodies used in the present invention. It is explanatory drawing of the measuring method of the outer diameter nonuniformity of the tube used for this invention. It is explanatory drawing of the measuring method of the straightness of the tube used for this invention. 1 is a schematic configuration diagram of an electrophotographic apparatus having a process cartridge having a charging roller of the present invention.

Explanation of symbols

1 Core (metal layer)
DESCRIPTION OF SYMBOLS 1 'Charging member 2 Foam elastic body layer 3 Functional multilayer tube 3 (i) Inner layer 3 (o) Outer layer 4 Die 5 Center through-hole 6 Extrusion flow path 7 Extrusion flow path 8 First extruder 9 Second push Ejector 10 Water-cooled ring 11 Power source 12 Photoconductor 13 Exposure light 14 Developing means 15 Transfer means 16 Transfer material 17 Fixing means 18 Cleaning means 19 Rail 20 Process cartridge 21 Take-off mechanism 22 Vibration suppression mechanism 23 Cutting mechanism 24 Stainless steel rod

Claims (9)

A charging member that has a mechanism for extruding a tube in the direction of gravity, an air cooling mechanism, a water cooling sizing mechanism, a tube take-off mechanism, and a tube cutting mechanism, and that covers an elastic body on the outer periphery of the core metal to cover a plurality of layers of seamless tubes. Coated tube manufacturing equipment for
After having the water-cooled sizing mechanism, it has a contact-type cutting vibration suppressing mechanism that contacts at least one of the tubes, so that the straightness of the charging member-coated tube is 1 mm or less and at least five outer diameters in the longitudinal direction. The difference Δ between the maximum value and the minimum value of the average value of the outer diameters at least at three locations in the circumferential direction at the measurement position is a 100 fraction value (Δ / Da × 100) with respect to the average value Da of all the outer diameter measurement values. An apparatus for producing a coated tube for a charging member, characterized by being made 2% or less.   2. The coated tube manufacturing apparatus for a charging member according to claim 1, wherein the contact-type vibration suppressing mechanism is means for contacting the tube at least at two points.   The charged tube coated tube manufacturing apparatus according to claim 2, wherein the tube contact means is at least one pair of rotation means whose rotation axis is orthogonal to a direction in which the tube is extruded.   The said rotating means is a cylindrical rotary body, The coating tube manufacturing apparatus for charging members of Claim 3.   The said rotating means is a belt body driven by the some cylindrical rotary body, The coating tube manufacturing apparatus for charging members in any one of Claims 1-4.   The said rotating means is a spherical rotary body, The coating tube manufacturing apparatus for charging members of Claim 3.   The charging member used for the charging mechanism of the electrophotographic apparatus is a charging member-coated tube obtained by the charging member-coated tube manufacturing apparatus according to any one of claims 1 to 6, wherein an elastic body formed on a core metal is used. A charging member formed by coating.   An electrophotographic apparatus cartridge, wherein the electrophotographic apparatus cartridge to which the electrophotographic apparatus is attachable and detachable mounts the charging member according to claim 7.   An electrophotographic apparatus comprising the electrophotographic apparatus cartridge according to claim 8.

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