JP2012220583A - Conductive member, process cartridge and electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive member in an electrophotographic device, the member having flexibility and low environmental dependence of the electric resistance and hardly inducing C-set (compression set) failure even when the member is left in contact with another member for a long period of time in a high temperature and high humidity environment.SOLUTION: The conductive member includes a conductive substrate 1 and an elastic layer 2. The elastic layer contains an ionic conductive rubber and hollow particles, wherein the hollow particles have a shell comprising a resin having a unit derived from ethylene oxide.

Description

  The present invention relates to a conductive member, a process cartridge using the conductive member, and an electrophotographic image forming apparatus (hereinafter referred to as “electrophotographic apparatus”).

In an electrophotographic apparatus adopting an electrophotographic system, for example, a conductive member is used as a member such as a charging member, a developing member, or a transfer member. Further, such a conductive member is required to have flexibility in order to ensure an appropriate nip width at a contact portion with a photosensitive member or the like.
Patent Document 1 discloses a conductive material including a shaft body and an elastic layer, the elastic layer is ionic conductive, and includes a micro hollow sphere having a shell made of an organic material or an inorganic material. A sex roller is disclosed. Such a conductive roller can reduce the hardness of the elastic layer due to the presence of bubbles formed by micro hollow spheres in the elastic layer, and the air bubbles formed by the micro hollow spheres are completely independent. It describes that the environmental dependence of the electrical resistance of the elastic layer can be reduced.

Incidentally, the conductive member is brought into contact with another member with a predetermined pressure in the electrophotographic apparatus. For this reason, when the conductive member is left in contact with another member for a long period of time, deformation that does not easily recover may occur in the contact portion of the conductive member. Such deformation is called compression set (hereinafter also referred to as “compression set” or “C set”). Further, the amount of compression set (hereinafter also referred to as “C set amount”) tends to increase when the conductive member is left in a high temperature and high humidity environment.
When a conductive member in which C set is generated is used as a charging member for the photosensitive member, when the portion where C set is generated (hereinafter referred to as “C setting portion”) passes through the discharge region, The minute discharge gap between the two fluctuates. For this reason, uneven charging occurs on the photosensitive member, which causes uneven density in the electrophotographic image.
When the present inventors examined the electroconductive member which concerns on patent document 1, it discovered that there was room for improvement about compression set.

JP 2001-82452 A

  Accordingly, an object of the present invention is for electrophotography which is flexible, has little environmental dependency of electrical resistance, and is less likely to cause C set even when it is kept in contact with other members for a long time under a high temperature and high humidity environment. It is in providing a conductive member. Another object of the present invention is to provide a process cartridge and an electrophotographic apparatus capable of stably providing high-quality electrophotographic images even under various environments.

According to the present invention, there is provided a conductive member having a conductive base and an elastic layer, wherein the elastic layer contains an ion conductive rubber and hollow particles, and the hollow particles have a unit derived from ethylene oxide. An electrically conductive member having a shell containing is provided.
In addition, according to the present invention, there is provided a process cartridge in which the above-described conductive member is at least integrated with a member to be charged and is configured to be detachable from the electrophotographic apparatus main body.
Furthermore, according to the present invention, an electrophotographic apparatus having the above conductive member is provided.

  According to the present invention, electroconductivity for electrophotography is flexible, has little environmental dependency on electrical resistance, and is less likely to cause C-set even when kept in contact with other members over a long period of time in a high temperature and high humidity environment. A sex member can be obtained. In addition, according to the present invention, it is possible to obtain a process cartridge and an electrophotographic apparatus that can stably provide high-quality electrophotographic images under various environments.

It is sectional drawing of the electroconductive roller which concerns on this invention. It is explanatory drawing of the measuring method of the electrical resistance value of the electroconductive roller which concerns on this invention. It is explanatory drawing of the measurement location of the film thickness of the surface layer of the electroconductive roller which concerns on this invention. 1 is a cross-sectional view of an electrophotographic apparatus according to the present invention. It is sectional drawing of the process cartridge which concerns on this invention. It is explanatory drawing of the extrusion molding apparatus for shape | molding a conductive roller. It is the schematic of the metal mold | die for carrying out the heating foaming of the electroconductive roller which concerns on this invention. It is the schematic which shows the contact state of the electroconductive roller which concerns on this invention, and an electrophotographic photoreceptor.

The present inventors presume the mechanism by which C set is generated in the conductive member according to Patent Document 1 as follows. That is, the conductive elastic layer containing the ion conductive rubber absorbs moisture and expands when placed in a high temperature and high humidity environment. At this time, since the hollow particles in the elastic layer cannot sufficiently follow the expansion of the elastic layer, there is a large difference in the degree of expansion of the elastic layer between the contact portion and the non-contact portion with other members. It is thought that the amount of C set becomes large.
Then, as a result of repeated studies to make the hollow particles follow the expansion due to moisture absorption of the elastic layer, the present inventors have found that the hollow particles having a shell containing a resin having a unit derived from ethylene oxide contain an ion conductive rubber. It has been found that the elastic layer well follows expansion due to moisture absorption. And when the electroconductive member provided with this elastic layer was made to contact | abut the other member on high temperature, high humidity conditions, it discovered that C set amount could be restrained small.

The conductive member according to the present invention will be described in detail below.
The conductive member according to the present invention is used, for example, in contact with an electrophotographic photosensitive member as a charging member or a developing member, and has a conductive base and an elastic layer, and the elastic layer is ion-conductive. -Containing rubber and hollow particles. The hollow particles have a shell containing a resin having units derived from ethylene oxide.
The ion conductive rubber expands due to moisture absorption when left in a high temperature and high humidity environment, and then contracts when left in a room temperature and normal humidity environment. Since the shell of the hollow particles used in the present invention is made of a resin having units derived from ethylene oxide, it easily expands and contracts due to environmental changes in temperature and humidity. For this reason, in this configuration, when the charging roller expands and contracts due to being left in a high temperature and high humidity environment, the hollow particles also expand and contract following. For this reason, the entire conductive member uniformly expands and contracts when left in a high-humidity and high-temperature environment, so that local deformation can be avoided, and the charging ability after leaving the high-temperature and high-humidity environment is stabilized.

  Moreover, since the shell of a hollow particle contains resin which has a unit derived from ethylene oxide, it has ionic conductivity. Therefore, the hollow particles serve as a conductive agent, and the resistance of the charging roller can be effectively reduced. Further, by adding an ionic conductive agent to the shell of the hollow particles, the resistance of the charging roller can be further reduced, and sufficient discharge from the charging roller can be ensured. It is considered that these effects make it possible to suppress the generation of the C set image.

<Charging member>
A cross-sectional view of a roller-shaped conductive member according to the present invention is shown in FIG. Hereinafter, the roller shape shown in FIG. 1, that is, the charging roller will be described in detail.
FIG. 1A shows a charging roller having a conductive substrate 1 and an elastic layer 2.
FIG. 1B shows a charging roller having an elastic layer 2 between the conductive substrate 1 and the surface layer 3.
The conductive substrate and the elastic layer, or the layers sequentially laminated (for example, the elastic layer and the surface layer shown in FIG. 1B) may be bonded via an adhesive. In this case, the adhesive is preferably conductive. In order to make it conductive, the adhesive may have a known conductive agent.

Examples of the binder resin for the adhesive include thermosetting resins and thermoplastic resins, and known ones such as urethane, acrylic, polyester, polyether, and epoxy resins can be used.
As a conductive agent for imparting conductivity to the adhesive, it can be appropriately selected from conductive agents described in detail later, and can be used alone or in combination of two or more.

The charging roller using the conductive member of the present invention usually has an electric resistance of 1 × 10 ² Ω or more in a 23 ° C./50% RH environment in order to improve the charging of the electrophotographic photosensitive member. More preferably, it is 10 ¹⁰ Ω or less.
As an example, FIG. 2 shows a method for measuring the electrical resistance of the charging roller. Both ends of the conductive substrate 1 are brought into contact with a cylindrical metal 32 having the same curvature as that of the electrophotographic photosensitive member by bearings 33 and 33 under load so as to be parallel to each other. In this state, the cylindrical metal 32 is rotated by a motor (not shown), and a DC voltage of −200 V is applied from the stabilized power supply 34 while the charging roller 5 that is in contact with the rotation is driven to rotate. The current flowing at this time is measured by an ammeter 35, and the resistance of the charging roller is calculated. In the present invention, the load was 4.9 N each, the diameter of the metal cylinder was 30 mm, and the rotation of the metal cylinder was 45 mm / sec.
The charging roller by the conductive member of the present invention has a shape in which the central portion in the longitudinal direction is the thickest and becomes narrower toward both ends in the longitudinal direction from the viewpoint of making the longitudinal nip width uniform with respect to the electrophotographic photosensitive member. A so-called crown shape is preferred. The crown amount is preferably such that the difference between the outer diameter at the center and the outer diameter at a position 90 mm away from the center is not less than 30 μm and not more than 200 μm.

  In the charging roller using the conductive member of the present invention, the surface ten-point average roughness Rzjis (μm) is 2 ≦ Rzjis ≦ 80, and the surface unevenness average interval RSm (μm) is 15 ≦ RSm ≦ 200. More preferred. By setting the surface roughness Rz and the average unevenness interval Rsm of the charging roller within this range, the contact state between the charging roller and the electrophotographic photosensitive member can be made more stable. This facilitates uniform charging of the photoreceptor.

A method for measuring the surface ten-point average roughness Rzjis and the surface unevenness average interval RSm will be described below.
It measures according to the specification of JIS B 0601-2001 surface roughness, and performs using surface roughness measuring instrument "SE-3500" (brand name, the Kosaka Laboratory Co., Ltd. product). Rzjis is an average value of the surface roughness measured at six locations randomly extracted from the surface of the charging member. Further, RSm is an average value of RSm at these six locations, by measuring the irregularity intervals at 10 points at 6 locations randomly extracted from the surface of the charging member and setting the average value as RSm at each location. The measurement conditions were cut-off value: 0.8 mm, filter: gauss, reserve length: cut-off × 2, leveling: straight line (entire area), evaluation length: 8 mm.

In order to control the ten-point average roughness and the uneven average interval within the above ranges, it is more preferable that particles having an average particle diameter of 1 μm or more and 100 μm or less are added to each layer described below, particularly the surface layer. About particle | grains, the filler explained in full detail later can be illustrated.
In addition, the charging roller using the conductive member of the present invention preferably has an outer diameter of 12 mm or less in order to achieve miniaturization and space saving of the electrophotographic apparatus.

[Conductive substrate]
The conductive substrate used for the charging member made of the conductive member of the present invention has conductivity and has a function of supporting an elastic layer or the like provided thereon. Examples of the material include metals such as iron, copper, stainless steel, aluminum, nickel, and alloys thereof. In addition, for the purpose of imparting scratch resistance to these surfaces, plating treatment or the like may be performed as long as the conductivity is not impaired. Furthermore, as the conductive substrate, a resin substrate whose surface is made conductive by coating the surface with a metal or the like, or a substrate manufactured from a conductive resin composition can be used.

[Elastic layer]
The elastic layer used in the conductive member of the present invention is a porous body formed of ion conductive rubber and containing hollow particles having a resin as a shell, and the resin has units derived from ethylene oxide. To do.
As the ion conductive rubber used for the elastic layer, a known rubber can be used.
Preferably, thermoplastic elastomers such as epichlorohydrin rubber, acrylonitrile-butadiene copolymer rubber (NBR), chloroprene rubber and urethane rubber are used. Since these are polar rubbers, the rubber itself has conductivity in the middle resistance region, and resistance adjustment is easy. In addition, variation in electric resistance depending on the position is small, and it is suitably used as a polymer elastic body. Among these, specifically, epichlorohydrin-mu-muethylene oxide copolymer, epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer, ethylene oxide-propylene oxide-allyl glycidyl ether terpolymer, and polyether urethane are preferable. .

The volume resistivity of the elastic layer is preferably 1 × 10 ² Ω · cm or more and 1 × 10 ⁹ Ω · cm or less as measured in a 23 ° C./50% RH environment.
The volume resistivity of the elastic layer is determined as follows. First, all materials used for the elastic layer are molded into a sheet having a thickness of 1 mm, and metal is vapor-deposited on both sides to form electrodes and guard electrodes, thereby obtaining a volume resistivity measurement sample. A voltage of 200 V is applied to the obtained volume resistivity measurement sample using a microammeter (trade name: ADVANTEST R8340A ULTRA HIGH RESISTANCE METER, manufactured by Advantest Corporation). Then, the current after 30 seconds is measured and calculated from the film thickness and the electrode area.
The volume resistivity of the elastic layer can be adjusted with an ionic conductive agent.

Examples of ionic conductive agents include inorganic ionic substances such as lithium perchlorate, sodium perchlorate, and calcium perchlorate, lauryltrimethylammonium chloride, stearyltrimethylammonium chloride, octadecyltrimethylammonium chloride, dodecyltrimethylammonium chloride, hexadecyltrimethylammonium. Cationic surfactants such as chloride, trioctylpropylammonium bromide, modified aliphatic dimethylethylammonium etosulphate, zwitterionic surfactants such as lauryl betaine, stearyl betaine, dimethylalkyl lauryl betaine, tetraethylammonium perchlorate, Quaternary ammonia such as tetrabutylammonium chlorate and trimethyloctadecylammonium perchlorate Umushio include organic lithium salts of lithium trifluoromethanesulfonate and the like. These can be used alone or in combination of two or more. Among ionic conductive agents, quaternary ammonium perchlorate is particularly preferably used because of its stable volume resistivity against environmental changes.
The elastic layer is a porous body containing hollow particles having a resin shell, and the resin has units derived from ethylene oxide.

  As the hollow particles for forming the porous material, particles in which the inside of the particles are bubbles may be used, or the inclusion material is contained in the inside of the particle, and the inclusion material expands by applying heat, so that the hollow particle is hollow. You may use what is called a thermally expansible microcapsule used as particle | grains. When the thermally expandable microcapsule is used in the present invention, the resin that becomes the shell expands due to the heat at the time of vulcanization of the elastic layer. Depending on the temperature conditions at the time of molding, the capsule can be molded while maintaining the shell structure without melting or rupturing.

  The substance to be encapsulated is a gas that expands as a gas at a temperature below the softening point of the shell of the hollow particles. High-boiling liquids such as hexane, isohexane, normal heptane, normal octane, isooctane, normal decane, and isodecane are often used, but are not limited thereto.

Resins having units derived from ethylene oxide include polyethylene oxide, poly (ethylene glycol acrylate), poly (ethylene glycol) methyl ether, poly (ethylene glycol) and polyethylene block copolymers, poly (ethylene glycol) and poly (ethylene Block copolymer of propylene glycol), block copolymer of poly (ethylene glycol) and poly (tetramethylene glycol), polyether urethane, polyether amide copolymer, polyether amide imide copolymer, polyether ester copolymer Examples thereof include a polymer and a polyetheresteramide copolymer. Among these, it is at least one selected from polyether urethane or polyether ester amide, and the content of units derived from ethylene oxide in the resin is 20% by weight or more and 90% by weight or less. preferable. By adopting such a configuration, it becomes easy to follow the deformation of the ion conductive rubber with respect to expansion due to moisture absorption in a high temperature and high humidity environment, and subsequent shrinkage due to leaving in a normal temperature and normal humidity environment, and low The charging ability is improved by resistance. Thereby, generation | occurrence | production of the C set image after leaving high temperature high humidity environment can be suppressed effectively.
These hollow particles can be produced by a known production method such as a suspension polymerization method, an interfacial polymerization method, an interfacial precipitation method, or a submerged drying method.

  In the suspension polymerization method, an oil phase to which a raw material monomer is added is added to an aqueous phase containing a dispersion stabilizer, and the mixture is stirred and mixed to form fine droplets of the raw material monomer. This is a method for producing hollow particles by polymerization. Specifically, an oil phase to which a raw material monomer, an inclusion substance, a polymerization initiator, a crosslinking agent and the like are added is prepared. Next, an aqueous phase to which a dispersion stabilizer, a dispersion stabilization auxiliary agent and the like are added is prepared. These oil phase and aqueous phase are mixed to prepare a dispersion. The dispersion is stirred and mixed, pressurized, and reacted by heating to produce a reaction product. The obtained reaction product is filtered, washed with water, and then dried to obtain desired hollow particles.

  The interfacial polymerization method is a method in which an emulsified dispersion prepared by mixing an aqueous phase to which an emulsifying dispersant and a hydrophilic raw material monomer are added and an oil phase to which a hydrophobic raw material monomer is added is reacted by heating to produce an aqueous phase. Is a method of producing hollow particles by performing polymerization at the interface between the oil phase and the oil phase. Specifically, an aqueous phase to which a hydrophilic raw material monomer and an emulsifying dispersant are added is prepared. Next, an oil phase in which the hydrophobic raw material monomer, the inclusion substance, and the crosslinking agent are dissolved is prepared. These aqueous phase and oil phase are mixed and mixed by stirring to prepare an emulsified dispersion in which the oil phase is dispersed in the aqueous phase. By stirring and mixing the dispersion, pressurizing and heating, the polymerization proceeds at the interface between the aqueous phase and the oil phase, and a reaction product is produced. The obtained reaction product is filtered, washed with water, and then dried to obtain desired hollow particles.

  The interfacial precipitation method is a production method in which a resin is precipitated and encapsulated using the difference in solubility between the solvent and the resin according to temperature, pH, solubility parameters, and the like. Specifically, first, a resin prepared in advance by a polymerization reaction is added to a solvent containing an inclusion substance. By adding a solvent (poor solvent) having low solubility with respect to the resin, resin particles are precipitated. At this time, the inclusion substance may be added in advance to the poor solvent. Alternatively, the resin may be dissolved in a solvent containing an inclusion substance, and then a poor solvent containing the inclusion substance may be added. Alternatively, the resin particles may be deposited by heating and dissolving the resin in a solvent containing the inclusion substance and then cooling. In any method, desired hollow particles can be obtained by filtration, washing and drying.

The in-liquid drying method is a production method in which a resin is dissolved in a solvent, added to a medium containing a dispersant to form a dispersion, and then the solvent is removed and encapsulated. Specifically, first, a resin solution is prepared by dissolving a resin prepared in advance by a polymerization reaction in a solvent containing an inclusion substance. Next, the resin solution is dispersed in an aqueous medium to which a dispersant is added, and the solvent is removed by heating and decompression. Thereafter, the desired hollow particles can be obtained by filtration, washing and drying.
The volume resistivity of the hollow particles is preferably 1 × 10 ¹⁰ Ω · cm or less as measured in a 23 ° C./50% RH environment.

  The volume resistivity of the hollow particles is measured in a 23 ° C./50% RH environment. Measurement is performed with electrodes in which cylindrical electrodes made of stainless steel (made of SUS316) are arranged above and below a cylinder made of polytetrafluoroethylene (PTFE) having an inner diameter of 1 cm. The measurement sample and the electrode are measured after being left in the above environment for 12 hours or longer and accustomed to the environment.

  A lower electrode made of SUS is arranged at the lower part of the PTFE cylinder, about 2 g of conductive particles are put so as not to be displaced, an SUS cylindrical electrode is placed from above, and sandwiched between the PTFE cylinder and the upper and lower electrodes. The sample is allowed to stand for 1 minute or more with a pressure of 10 MPa applied. Thereafter, a voltage of 200 V is applied using a microammeter (trade name: ADVANTEST R8340A ULTRA HIGH RESISTANCE METER, manufactured by Advantest Corporation). Then, the current after 30 seconds is measured and calculated from the distance between the electrode surfaces and the electrode area.

  An ionic conductive agent can be contained in the shell of the hollow particles. Examples of the ion conductive agent include ammonium salts and lithium salts. Specifically, tetraethylammonium perchlorate, tetrabutylammonium perchlorate, quaternary ammonium salts such as trimethyloctadecyl ammonium perchlorate, lithium perchlorate, lithium tetrafluoroborate, lithium trifluoromethanesulfonate, etc. Organic acid lithium salt is mentioned. These can be used alone or in combination of two or more. With such a configuration, the elastic layer has a low resistance, and generation of a C set image after being left in a high temperature and high humidity environment can be suppressed. Furthermore, the effect which contributes to suppression of a C set image becomes high by making a quaternary ammonium salt into the structure of perchloric acid. The amount of the ion conductive agent contained in the shell is preferably 1 part by mass or more and 30 parts by mass or less with respect to the resin constituting the shell.

As a compounding quantity at the time of mix | blending a hollow particle with an elastic layer, 2 mass parts or more and 20 mass parts or less are preferable.
The average diameter of the hollow particles in the elastic layer is preferably 30 μm or more and 300 μm or less, and the thickness of the shell is preferably 0.05 μm or more and 5 μm or less, more preferably 0.1 μm or more and 1 μm or less. By setting the particle size to such a value, the resistance of the porous body can be effectively reduced.

The elastic layer can contain a filler as long as the effects of the present invention are not impaired.
Fillers include zinc oxide, indium oxide, titanium oxide (titanium dioxide, titanium monoxide, etc.), iron oxide, silica, alumina, magnesium oxide, zirconium oxide, strontium titanate, calcium titanate, magnesium titanate, barium titanate , Calcium zirconate, barium sulfate, molybdenum disulfide, calcium carbonate, magnesium carbonate, dolomite, talc, kaolin clay, mica, aluminum hydroxide, magnesium hydroxide, zeolite, wollastonite, diatomaceous earth, glass beads, bentonite, Mention may be made of particles such as montmorillonite, hollow glass spheres, organometallic compounds and organometallic salts. Further, iron oxides such as ferrite, magnetite, and hematite, activated carbon, and the like can also be used.

These fillers may be used alone or in combination of two or more, and may be subjected to surface treatment, modification, introduction of functional groups and molecular chains, coating, and the like. In order to improve the dispersibility of the filler, it is more preferable that the filler is subjected to a surface treatment.
As the surface treatment agent, organosilicon compounds such as alkoxysilanes, fluoroalkylsilanes, polysiloxanes, etc., various silane, titanate, aluminate and zirconate coupling agents, oligomers or polymer compounds can be used. These may be used alone or in combination of two or more. Other examples include surface treatment with fatty acids and fatty acid metal salts. As the fatty acid, a saturated or unsaturated fatty acid can be used, and those having 12 to 22 carbon atoms are preferable. As the fatty acid metal salt, a salt of a saturated or unsaturated fatty acid and a metal can be used. Specifically, fatty acids having 12 to 18 carbon atoms and alkaline earth metals such as magnesium, calcium, strontium and barium, alkali metals such as lithium, sodium and potassium, zinc, aluminum, copper, iron, lead and tin Mention may be made of salts with metals.

The surface treatment agent is preferably used in an amount of 0.01 to 15.0 parts by mass with respect to 100 parts by mass of the filler, and if within this range, sufficient dispersibility can be imparted to the filler. More preferably, it is 0.02 mass part to 12.5 mass parts or less, More preferably, it is 0.03 mass part to 10.0 mass parts.
Moreover, in order to adjust hardness etc., you may add additives, such as softening oil and a plasticizer, to an elastic layer. The amount of the plasticizer or the like is preferably 1 to 30 parts by mass, more preferably 3 to 20 parts by mass with respect to 100 parts by mass of the elastic layer material. It is more preferable to use a polymer type plasticizer. The molecular weight of the polymer plasticizer is preferably 2000 or more, more preferably 4000 or more.

Furthermore, the elastic layer may appropriately contain materials that impart various functions. Examples of these include anti-aging agents and fillers.
The hardness of the elastic layer is preferably 70 ° or less, particularly 60 ° or less in terms of micro hardness (MD-1 type). This is for obtaining a nip having a sufficient width between the charging member and the electrophotographic photosensitive member. In addition, "micro hardness (MD-1 type)" is the hardness of the charging member measured using Asker micro rubber hardness meter MD-1 type (trade name, manufactured by Kobunshi Keiki Co., Ltd.). Specifically, the hardness meter is a value measured in a 10 N peak hold mode with respect to a charging member left for 12 hours or more in a 23 ° C./50% RH environment.

The elastic layer may be subjected to a surface treatment. Examples of the surface treatment include a surface processing treatment using UV or electron beam, and a surface modification treatment for adhering and / or impregnating a compound or the like on the surface.
The elastic layer can be formed by adhering or coating a sheet-shaped or tube-shaped layer formed in advance to a predetermined film thickness on a conductive substrate. In addition, the conductive substrate and the elastic layer material can be integrally extruded by using an extruder equipped with a cross head.
As a method for dispersing the conductive agent, hollow particles, insulating particles, filler, and the like in the elastic layer material, known methods such as mixing with a ribbon blender, nauter mixer, Henschel mixer, super mixer, Banbury mixer, pressure kneader, etc. This method can be used.

[Surface layer]
In the conductive member of the present invention, a surface layer may be formed on the conductive rubber elastic layer. When the surface layer is provided, the volume resistivity of the surface layer is preferably set to 1 × 10 ³ Ω · cm or more and 1 × 10 ¹⁵ Ω · cm or less in an environment of a temperature of 23 ° C. and a humidity of 50%. .
The volume resistivity of the surface layer is determined as follows. First, the surface layer is peeled off from the roller state and cut into a 5 mm × 5 mm strip. Metal is vapor-deposited on both surfaces to produce an electrode and a guard electrode, and a measurement sample is obtained. Alternatively, it is applied on an aluminum sheet to form a surface layer coating film, and a metal for vapor deposition is deposited on the coating film surface to obtain a measurement sample. The obtained measurement sample can be measured in the same manner as the volume resistivity measurement method for the elastic layer. The volume resistivity of the surface layer can be adjusted by a conductive agent such as an ionic conductive agent or an electronic conductive agent.

As a standard of the film thickness of the surface layer, 0.1 μm to 100 μm, particularly 1 μm to 50 μm is preferable. The film thickness of the surface layer can be measured by cutting the roller cross section with a sharp blade at the position shown in FIGS. 3A and 3B and observing it with an optical microscope or an electron microscope.
The surface layer may be subjected to a surface treatment. Examples of the surface treatment include a surface processing treatment using UV or electron beam, and a surface modification treatment for adhering and / or impregnating a compound or the like on the surface.

  The surface layer can be formed by a coating method such as electrostatic spray coating or dipping coating. Or it can also form by adhere | attaching or coat | covering the sheet-shaped or tube-shaped layer beforehand formed into a predetermined film thickness. Alternatively, a method of curing and molding the material into a predetermined shape in the mold can also be used. Among these, it is preferable to apply a paint by a coating method to form a coating film.

<Electrophotographic device>
FIG. 4 shows a schematic configuration of an example of an electrophotographic apparatus provided with a charging member made of a conductive member of the present invention. The electrophotographic apparatus includes an electrophotographic photosensitive member, a charging device that charges the electrophotographic photosensitive member, a latent image forming device that performs exposure, a developing device that develops a toner image, a transfer device that transfers to a transfer material, and an electrophotographic photosensitive member. A cleaning device for collecting the transfer toner, a fixing device for fixing the toner image, and the like are included. The electrophotographic photoreceptor 4 is a rotary drum type having a photosensitive layer on a conductive substrate. The electrophotographic photosensitive member is driven to rotate at a predetermined peripheral speed (process speed) in the direction of the arrow.

  The charging device includes a contact-type charging roller 5 that is placed in contact with the electrophotographic photosensitive member 4 by contacting with the electrophotographic photosensitive member 4 with a predetermined pressing force. The charging roller 5 is driven rotation that rotates according to the rotation of the electrophotographic photosensitive member 4, and charges the electrophotographic photosensitive member 4 to a predetermined potential by applying a predetermined voltage from the charging power source 19.

As the latent image forming apparatus 11 that forms an electrostatic latent image on the electrophotographic photosensitive member 4, for example, an exposure apparatus such as a laser beam scanner is used. An electrostatic latent image is formed by performing exposure corresponding to image information on the uniformly charged electrophotographic photosensitive member.
The developing device has a developing roller 6 disposed close to or in contact with the electrophotographic photosensitive member 4. The toner electrostatically processed to the same polarity as the charged polarity of the electrophotographic photosensitive member is reversely developed to visualize and develop the electrostatic latent image into a toner image.

  The transfer device has a contact-type transfer roller 8. The toner image is transferred from the electrophotographic photosensitive member 4 to a transfer material 7 such as plain paper (the transfer material is conveyed by a paper feeding system having a conveying member). The cleaning device includes a blade-type cleaning member 10 and a collection container, and after transfer, mechanically scrapes and collects transfer residual toner remaining on the electrophotographic photosensitive member. Here, it is possible to omit the cleaning device by adopting a development simultaneous cleaning system in which the transfer device collects the transfer residual toner. The fixing device 9 is composed of a heated roller or the like, and fixes the transferred toner image on the transfer material 7 and discharges it outside the apparatus.

<Process cartridge>
It is also possible to use a process cartridge (FIG. 5) designed to be detachable from the electrophotographic apparatus by integrating an electrophotographic photosensitive member, a charging device, a developing device, a cleaning device, and the like.
That is, the charging member is a process cartridge that is at least integrated with the member to be charged and is configured to be detachable from the main body of the electrophotographic apparatus, and the charging member is the above-described charging member.
The electrophotographic apparatus includes at least a process cartridge, an exposure device, and a fixing device, and the process cartridge is the process cartridge described above.

  Hereinafter, the present invention will be described in more detail with reference to specific examples.

Production Example A-1 (Preparation of hollow particles 1)
35 parts by mass of toluene was added to 240 parts by mass of polyethylene glycol monomethyl ether. Further, 160 parts by mass of xylylene diisocyanate / trimethylolpropane adduct (Takenate D110N, 75 wt% ethyl acetate solution, manufactured by Takeda Pharmaceutical Co., Ltd.) was added, and the reaction was carried out at 120 ° C. for 5 hours under toluene reflux. . Thereafter, toluene was distilled off under reduced pressure to obtain polyether urethane. The content of units derived from ethylene oxide measured by NMR was 61% by weight.
400 parts by mass of polyether urethane obtained, 12 parts by mass of yellow iron oxide, 62 parts by mass of n-hexane, 380 parts by mass of ethyl acetate, quaternary ammonium perchlorate (Adekasizer LV-70, manufactured by Asahi Denka Kogyo) 80 parts by mass The parts were mixed. This mixed solution was dispersed while being dropped into 2000 parts by mass of a 0.5% aqueous polyvinyl alcohol solution prepared in advance. The obtained resin was taken out of the water by filter paper filtration and dried by a circulating air dryer at 40 ° C. The spherical body was crushed by a sonic classifier and sieved to obtain hollow particles 1. The obtained hollow particles had a particle size of 50.6 μm.

Production Example A-2 (Preparation of hollow particles 2)
Hollow particles 2 were obtained in the same manner as in Production Example A-1, except that the amount of perchloric acid quaternary ammonium salt was changed to 20 parts by mass. The particle size of the obtained hollow particles was 51.3 μm.

Production Example A-3 (Preparation of hollow particles 3)
The difference in particle diameter classified when pulverized and screened with a sonic classifier in Production Example A-1 was designated as hollow particle 3. The particle size of the obtained hollow particles was 135.4 μm.

Production Example A-4 (Preparation of hollow particles 4)
Hollow particles 4 were obtained in the same manner as in Production Example A-1, except that the blending amount of n-hexane was changed to 124 parts by mass. The obtained hollow particles had a particle size of 49.4 μm.

Production Example A-5 (Preparation of hollow particles 5)
Hollow particles 5 were obtained in the same manner as in Production Example A-1, except that the quaternary ammonium perchlorate was changed to tetrabutylammonium perchlorate (reagent, manufactured by Kanto Chemical Co., Inc.). The particle size of the obtained hollow particles was 49.9 μm.

Production Example A-6 (Preparation of hollow particles 6)
In a stainless steel autoclave, 134 parts by mass of ε-caprolactam, 26 parts by mass of adipic acid, 0.6 parts by mass of antioxidant, and 10 parts by mass of water were placed. After the atmosphere in the autoclave was replaced with nitrogen, it was pressurized and sealed at 220 ° C. The reaction was carried out with stirring for 4 hours. Thereafter, the pressure was reduced and unreacted ε-caprolactam was distilled off at 1 torr or less for 3 hours to obtain polyamide. Next, 240 parts by mass of polyethylene glycol and 1 part by mass of zirconyl acetate were further added, and a polymerization reaction was carried out at 245 ° C. under a reduced pressure of 1 torr or less for 5 hours to obtain a polyether ester amide copolymer. The content of units derived from ethylene oxide measured by NMR was 60% by weight.
400 parts by mass of the obtained polyetheresteramide copolymer, 12 parts by mass of yellow iron oxide, 62 parts by mass of n-hexane, 380 parts by mass of ethyl acetate, quaternary ammonium perchlorate (Adekasizer LV-70 Asahi Denka Kogyo Made). This mixed solution was dispersed while being dropped into 2000 parts by mass of a 0.5% aqueous polyvinyl alcohol solution prepared in advance. The obtained resin was taken out of the water by filter paper filtration and dried by a circulating air dryer at 40 ° C. The spherical body was crushed with a sonic classifier and sieved to obtain hollow particles. The particle size of the obtained hollow particles was 50.3 μm. This was designated as hollow particles 6.

Production Example A-7 (Production of hollow particles 7)
Hollow particles 7 were obtained in the same manner as in Production Example A-1, except that the polyethylene glycol monomethyl ether was changed to 120 parts by mass and the xylylene diisocyanate / trimethylolpropane adduct was changed to 280 parts by mass. The content of units derived from ethylene oxide measured by NMR was 30% by weight. The particle size of the obtained hollow particles was 51.1 μm.

Production Example A-8 (Preparation of hollow particles 8)
Put 384 parts by weight of dimethyl terephthalate, 240 parts by weight of ethylene glycol and 0.2 parts of manganese acetate tetrahydrate in a stainless steel autoclave and heat at 200 ° C. for 3 hours. An exchange reaction was performed. Next, 160 parts by mass of terminal diamine-modified polyethylene glycol, 0.3 parts by mass of antimony trioxide, and 0.15 parts by mass of trimethyl phosphate were further added, and the temperature was raised to 260 ° C. Thereafter, the inside of the autoclave was depressurized to 1 torr or less, and the polymerization reaction was carried out for 3 hours while maintaining the pressure at 1 torr or less while distilling off excess ethylene glycol. Thereafter, purification was performed to obtain a polyetheramide copolymer. The content of units derived from ethylene oxide measured by NMR was 64% by weight.
400 parts by mass of the obtained polyetheramide copolymer, 12 parts by mass of yellow iron oxide, 62 parts by mass of n-hexane, 380 parts by mass of ethyl acetate, quaternary ammonium perchlorate (Adekasizer LV-70, manufactured by Asahi Denka Kogyo Co., Ltd. ) Was mixed. This mixed solution was dispersed while being dropped into 2000 parts by mass of a 0.5% aqueous polyvinyl alcohol solution prepared in advance. At this time, the obtained resin was taken out of the water by filter paper filtration and dried by a circulating dryer at 40 ° C. The spherical body was crushed with a sonic classifier and sieved to obtain hollow particles. The obtained hollow particles had a particle size of 49.4 μm. This was designated as hollow particles 8.

Production Example A-9 (Preparation of hollow particles 9)
Hollow particles 9 were obtained in the same manner as in Production Example A-1, except that 380 parts by mass of polyethylene glycol monomethyl ether and 200 parts by mass of the xylylene diisocyanate / trimethylolpropane adduct were changed. The content of units derived from ethylene oxide measured by NMR was 95% by weight. The resulting hollow particles had a particle size of 50.7 μm.

Production Example A-10 (Production of hollow particles 10)
Hollow particles 10 were obtained in the same manner as in Production Example A-1, except that polyethylene glycol monomethyl ether was changed to 40 parts by mass and xylylene diisocyanate / trimethylolpropane adduct was changed to 360 parts by mass. The content of units derived from ethylene oxide measured by NMR was 10% by weight. The particle size of the obtained hollow particles was 50.2 μm.

Production Example A-11 (production of hollow particles 11)
Hollow particles 11 were obtained in the same manner as in Production Example A-1, except that the quaternary ammonium perchlorate was changed to tetrabutylammonium chloride (reagent, manufactured by Tokyo Chemical Industry Co., Ltd.). The obtained hollow particles had a particle size of 49.8 μm.

Production Example A-12 (Preparation of hollow particles 12)
Hollow particles 12 were obtained in the same manner as in Production Example A-1, except that the quaternary ammonium perchlorate was changed to lithium tetrafluoroborate (reagent, manufactured by Kishida Chemical). The obtained hollow particles had a particle size of 50.5 μm.

Production Example A-13 (Preparation of hollow particles 13)
Hollow particles 13 were obtained in the same manner as in Production Example A-1, except that the perchloric acid quaternary ammonium salt was changed to lithium perchlorate (reagent, manufactured by Kanto Chemical). The particle size of the obtained hollow particles was 50.0 μm.

Production Example A-14 (Preparation of hollow particles 14)
Hollow particles 14 were obtained in the same manner as in Production Example A-8 except that the quaternary ammonium perchlorate was changed to tetrabutylammonium chloride (reagent, manufactured by Tokyo Chemical Industry Co., Ltd.). The obtained hollow particles had a particle size of 50.8 μm.

Production Example A-15 (Production of hollow particles 15)
Hollow particles 15 were obtained in the same manner as in Production Example A-11 except that polyethylene glycol monomethyl ether was changed to 40 parts by mass and xylylene diisocyanate / trimethylolpropane adduct was changed to 360 parts by mass. The content of units derived from ethylene oxide measured by NMR was 95% by weight. The obtained hollow particles had a particle size of 49.8 μm.

Production Example A-16 (production of hollow particles 16)
Hollow particles 16 were obtained in the same manner as in Production Example A-11 except that 380 parts by mass of polyethylene glycol monomethyl ether and 20 parts by mass of xylylene diisocyanate / trimethylolpropane adduct were changed. The content of units derived from ethylene oxide measured by NMR was 8% by weight. The obtained hollow particles had a particle size of 49.4 μm.

Production Example A-17 (production of hollow particles 17)
A hollow particle 17 was obtained in the same manner as in Production Example A-1, except that no perchloric acid quaternary ammonium salt was added. The obtained hollow particles had a particle size of 50.6 μm.

Production Example A-18 (production of hollow particles 18)
A hollow particle 18 was obtained in the same manner as in Production Example A-8 except that a quaternary ammonium perchlorate salt was not blended. The particle size of the obtained hollow particles was 50.3 μm.

Production Example A-19 (production of hollow particles 19)
Hollow particles 19 were obtained in the same manner as in Production Example A-17 except that 380 parts by mass of polyethylene glycol monomethyl ether and 200 parts by mass of the xylylene diisocyanate / trimethylolpropane adduct were changed. The content of units derived from ethylene oxide measured by NMR was 96% by weight. The obtained hollow particles had a particle size of 50.8 μm.

Production Example A-20 (Preparation of hollow particles 20)
Hollow particles 20 were obtained in the same manner as in Production Example A-17, except that polyethylene glycol monomethyl ether was changed to 40 parts by mass and xylylene diisocyanate / trimethylolpropane adduct was changed to 360 parts by mass. The content of units derived from ethylene oxide measured by NMR was 10% by weight. The particle size of the obtained hollow particles was 49.9 μm.

Production Example B-1 (Preparation of surface layer coating solution)
Methyl isobutyl ketone was added to the caprolactone-modified acrylic polyol solution to prepare a solid content of 17% by mass.
The components listed in Table 1 were added to 588.24 parts by mass of this solution (100 parts by mass of acrylic polyol solid content) to prepare a mixed solution.

At this time, the blocked isocyanate mixture was such that the amount of isocyanate was “NCO / OH = 1.0”.
(* 1) Modified dimethyl silicone oil “SH28PA” (trade name, manufactured by Toray Dow Corning Silicone Co., Ltd.)
(* 2) 7: 3 mixture of each butanone oxime block of hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI).
200 g of the above mixed solution is placed in a glass bottle with an internal volume of 450 mL together with 200 g of glass beads having an average particle diameter of 0.8 mm as a medium, and dispersed for 24 hours using a paint shaker disperser to remove the glass beads and apply for the surface layer. A solution was obtained.

Example 1
[Production of roller having elastic layer]
A thermosetting adhesive containing 10% carbon black was applied to a stainless steel substrate having a diameter of 6 mm and a length of 252.5 mm, and the dried one was used as a conductive substrate. Epichlorohydrin rubber (EO-EP-AGE ternary copolymer) (trade name: Epion 301, manufactured by Daiso Co., Ltd.) 100 parts by mass, the components shown in Table 2 were added and the sealed mixer adjusted to 50 ° C Was mixed for 10 minutes to prepare a raw material compound.

To this was added 0.8 part by mass of sulfur as a vulcanizing agent. Furthermore, as a vulcanization accelerator, 1 part by mass of dibenzothiazyl sulfide (DM) (trade name: Noxeller DM, manufactured by Ouchi Shinsei Chemical Co., Ltd.), tetramethylthiuram monosulfide (TS) (trade name: Noxeller TS, large 0.5 parts by mass of Uchinsei Chemical Co., Ltd.) was added. 15 parts by mass of the hollow particles 1 was added thereto, and the mixture was kneaded for 10 minutes with a two-roll mill cooled to 20 ° C. to obtain an elastic layer compound.
Subsequently, using an extrusion molding apparatus having a cross head shown in FIG. 6, the elastic layer compound is coated coaxially and cylindrically with the conductive substrate as the central axis, and the outer diameter of the elastic layer is the diameter ( A charging member preform having a diameter of 10 mm was obtained.

  The crosshead is a device generally used for covering electric wires and wires, and is used by being attached to a rubber discharge portion of a cylinder of an extruder. The end portion of the conductive base was exposed by removing the end portion of the elastic layer of the charging member preform. Next, as schematically shown in FIG. 7, the charging member preform is placed in a mold having a cylindrical cavity having an inner diameter (φ) of 12 mm, and the charging member preform is heated and foamed. A charging member was obtained. The mold was heated at 160 ° C. for 20 minutes using a heater and a temperature adjusting device (not shown). Further, the obtained charging member was heated at 160 ° C. for 30 minutes in the hot air furnace to perform secondary vulcanization, and a charging roller having a porous conductive elastic layer having an outer diameter of 12 mm and a length of 224.2 mm Got.

[Production of Charging Roller 1]
The surface layer coating solution prepared in Production Example B-1 was dipped onto the charging member once. After air-drying at room temperature for 30 minutes or more, it was dried at 80 ° C. for 1 hour and further at 160 ° C. for 1 hour with a hot-air circulating dryer to obtain a charging roller 1 having a surface layer formed on the elastic layer. Here, the dipping application was performed by dipping time of 9 seconds, the dipping application lifting speed was an initial speed of 20 mm / sec, and a final speed of 2 mm / sec, while the speed was changed linearly with respect to time.

[Measurement of electric resistance value of charging roller 1]
The resistance of the charging roller 1 was measured using the electrical resistance value measuring device shown in FIG.
First, the charging roller is brought into contact with the cylindrical metal 32 (diameter 30 mm) by bearings 33a and 33b so as to be parallel to the cylindrical metal 32 (FIG. 2A).
Here, the contact pressure was adjusted to 4.9 N at one end and 9.8 N in total at both ends by the pressing force of the spring. Next, the charging roller is driven to rotate in accordance with the cylindrical metal 32 that is driven to rotate at a peripheral speed of 45 mm / sec by a motor (not shown). During the driven rotation, as shown in FIG. 2B, a DC voltage of −200 V is applied from the stabilized power source 34, and the current value flowing through the charging roller is measured by the ammeter 35. The resistance of the charging roller was calculated from the applied voltage and current value. The charging roller 1 was left in a 23 ° C./50% RH environment for 24 hours or more, and then the electric resistance value was measured. The electric resistance value of the charging roller 1 was 8.5 × 10 ⁴ Ω.

[Section observation of charging roller 1]
The average particle diameter of the hollow particles in the elastic layer and the thickness of the shell were measured with a scanning electron microscope (SEM). The cut section was observed with a scanning electron microscope and measured at arbitrary five points. As a result, it was found that the hollow particles 1 had an average particle size of 92 μm and a shell thickness of 2.3 μm.

[Evaluation of C set image]
As an electrophotographic apparatus having the configuration shown in FIG. 4, a color laser jet printer (HP Color LaserJet 4700dn) manufactured by Hewlett-Packard Co. was used with a recording medium output speed of 200 mm / sec (A4 vertical output). The resolution of the image is 600 dpi, and the primary charging output is a DC voltage of −1100V.
The process cartridge for the printer was used as a process cartridge having the configuration shown in FIG. 5 (for black).
The attached charging roller was removed from the process cartridge, and the charging roller using the conductive member of the present invention was set. The charging roller was brought into contact with the photosensitive member with a pressing force of a spring of 4.9 N at one end and a total of 9.8 N at both ends (FIG. 8).
The process cartridge was left in a 40 ° C./95% RH environment for 1 month (severely left). Next, the process cartridge was allowed to stand for 6 hours in an environment of 23 ° C./50% RH, and then mounted on the electrophotographic apparatus, and an image was output in the same environment. A halftone image (an image in which a horizontal line having a width of 1 dot and an interval of 2 dots is drawn in the direction perpendicular to the rotation direction of the photoreceptor) was output as an evaluation image. The C set image was evaluated for the output image. The evaluation results are shown in Table 12. Here, the evaluation criteria are as follows.
Rank 1: No C set image is generated.
Rank 2: Only a slight streak-like image is recognized.
Rank 3: Some streaky images can be confirmed with the pitch of the charging roller, but the image quality has no practical problem.
Rank 4: A streak-like image is conspicuous and a deterioration in image quality is recognized.

[Measurement of C set amount]
After the image output, the charging roller was removed from the process cartridge, and the radius of the charging roller in each of the C set portion and the non-C set portion was measured. The difference between the radius of the non-C set portion and the radius of the C set portion is the C set amount. For the measurement, a fully automatic roller measuring device manufactured by Tokyo Koden Kogyo Co., Ltd. was used. The charging roller was rotated by 1 ° at each of the charging roller longitudinal center portion and three positions 90 mm on the left and right sides from the center portion, and the positions corresponding to the C set portion and the non-C set portion were measured. Next, the difference between the maximum value of the radius of the non-C set portion and the minimum value of the radius of the C set portion was calculated. The value having the largest radius difference among the three locations was defined as the C set amount in the present invention. The results are shown in Table 12. The charging roller 1 of this example did not generate a C set image, and a good image was obtained.

(Examples 2 to 4)
Charge rollers 2 to 4 were produced in the same manner as in Example 1 except that the hollow particles 1 were changed to the hollow particles shown in Table 12. In the manufactured charging roller, the electrical resistance value measurement of the charging roller, the average particle diameter of the hollow particles, the measurement of the C set amount, and the evaluation of the C set image were performed in the same manner as in Example 1. The results are shown in Table 12. In Examples 2 to 4, no C set image was generated, and a good image was obtained.

(Example 5)
A charging roller 5 was produced in the same manner as in Example 1 except that the addition amount of the hollow particles 1 was changed as shown in Table 12. In the manufactured charging roller 5, the electrical resistance value measurement of the charging roller 5, the average particle diameter of the hollow particles, the measurement of the C set amount, and the evaluation of the C set image were performed in the same manner as in Example 1. The results are shown in Table 12. In Example 5, a C set image was not generated and a good image was obtained.

(Example 6)
A charging roller 6 was produced in the same manner as in Example 1 except that the surface layer was not applied. In the manufactured charging roller 6, the electrical resistance value measurement of the charging roller, the average particle diameter of the hollow particles, the measurement of the C set amount, and the evaluation of the C set image were performed in the same manner as in Example 1. The results are shown in Table 12.
In Example 6, a C set image was not generated and a good image was obtained.

(Example 7)
In the same manner as in Example 1, a charging member preform was obtained in which the outer diameter of the elastic layer was 10 mm in diameter (φ). The obtained charging member preform was heated in a hot air oven at 160 ° C. for 1 hour, and then the end of the porous conductive elastic layer was removed. The outer diameter was 9.0 mm and the length was 9.0 mm. A charging member having a porous conductive elastic layer of 224.2 mm was obtained.
Next, the outer peripheral surface of the porous conductive elastic layer of the charging member was polished using a plunge cut type cylindrical polishing machine, and the outer diameter of the porous conductive elastic layer was adjusted to a diameter (φ) of 12 mm.
The surface layer coating solution prepared in Production Example B-1 was dipped on the charging member once. After air-drying at room temperature for 30 minutes or more, it was dried with a hot air circulating dryer at 80 ° C. for 1 hour and further at 160 ° C. for 1 hour to produce a charging roller 7 having a surface layer formed on the elastic layer. In the manufactured charging roller 7, the electrical resistance value measurement of the charging roller, the average particle diameter of the hollow particles, the measurement of the C set amount, and the evaluation of the C set image were performed in the same manner as in Example 1. The results are shown in Table 12.
In Example 7, no C set image was generated, and a good image was obtained.

(Example 8)
A charging roller 8 was produced in the same manner as in Example 7 except that the surface layer was not applied. In the manufactured charging roller 8, the electrical resistance value measurement of the charging roller, the average particle diameter of the hollow particles, the measurement of the C set amount, and the evaluation of the C set image were performed in the same manner as in Example 1. The results are shown in Table 12.
In Example 8, a C set image was not generated and a good image was obtained.

(Examples 9 to 11)
Charge rollers 9 to 11 were produced in the same manner as in Example 1 except that the hollow particles 1 were changed to the hollow particles shown in Table 12. In the manufactured charging roller, the electrical resistance value measurement of the charging roller, the average particle diameter of the hollow particles, the measurement of the C set amount, and the evaluation of the C set image were performed in the same manner as in Example 1. The results are shown in Table 12.
In Examples 9 to 11, no C set image was generated, and a good image was obtained.

(Example 12)
In preparing the compound for the elastic layer, first, the materials shown in Table 3 were kneaded for 15 minutes in a closed mixer adjusted to 50 ° C. to prepare a raw material compound.

  With respect to 141 parts by mass of this raw material compound, the materials shown in Table 4 were blended and kneaded for 15 minutes in a two-roll machine cooled to 20 ° C. to obtain an elastic layer compound.

A charging roller 12 was produced in the same manner as in Example 1 except that this elastic layer compound was used.
In the manufactured charging roller 12, the electrical resistance value measurement of the charging roller, the average particle diameter of the hollow particles, the measurement of the C set amount, and the evaluation of the C set image were performed in the same manner as in Example 1. The results are shown in Table 12.
In Example 12, a C set image was not generated and a good image was obtained.

(Example 13)
In preparing the compound for the elastic layer, first, the materials shown in Table 5 were kneaded for 15 minutes in a closed mixer adjusted to 50 ° C. to prepare a raw material compound.

  With respect to 141 parts by mass of this raw material compound, the materials shown in Table 6 were blended and kneaded for 15 minutes in a two-roll machine cooled to 20 ° C. to obtain an elastic layer compound.

A charging roller 13 was produced in the same manner as in Example 1 except that this elastic layer compound was used.
In the manufactured charging roller 13, the electrical resistance value measurement of the charging roller, the average particle diameter of the hollow particles, the measurement of the C set amount, and the evaluation of the C set image were performed in the same manner as in Example 1. The results are shown in Table 12.
In Example 13, no C set image was generated, and a good image was obtained.

(Example 14)
The materials listed in Table 7 were mixed and reacted at 70 ° C. for 3 hours under a nitrogen atmosphere to obtain a polyether urethane (EU) prepolymer having NCO = 7.6%.

For 100 parts by weight of the prepolymer, 1 part by weight of PX-4B manufactured by Nippon Chemical Industry Co., Ltd. as a phosphonium salt type cationic conductivity imparting agent, and 3,3′-dichloro-4,4′-diaminodiphenylmethane 21 .7 parts by weight of heat melted at 120 ° C. was added. To this, 15 parts by mass of hollow particles 1 was added and mixed for 1-2 minutes. After pouring the mixture into a mold set with a core metal and curing at 110 ° C. for 30 minutes, the mixture is removed from the mold and aftercured at 110 ° C. for 4 hours. The outer diameter is 12 mm in diameter and the length is A charging roller 14 having a porous conductive elastic layer of 224.2 mm was obtained.
In the manufactured charging roller 14, the electrical resistance value of the charging roller, the average particle diameter of the hollow particles, the measurement of the C set amount, and the evaluation of the C set image were performed in the same manner as in Example 1. The results are shown in Table 12.
In Example 14, no C set image was generated, and a good image was obtained.

(Example 15)
In preparing the compound for the elastic layer, first, the materials shown in Table 8 were kneaded for 15 minutes in a closed mixer adjusted to 50 ° C. to prepare a raw material compound.

  With respect to 141 parts by mass of this raw material compound, the materials shown in Table 9 were blended and kneaded for 15 minutes in a two-roll machine cooled to 20 ° C. to obtain an elastic layer compound.

  A charging roller 15 was produced in the same manner as in Example 1 except that this elastic layer compound was used. In the manufactured charging roller 15, the electrical resistance value of the charging roller, the average particle diameter of the hollow particles, the measurement of the C set amount, and the evaluation of the C set image were performed in the same manner as in Example 1. The results are shown in Table 12. In Example 15, only a slight C set image was recognized in a part of the image, and an overall good image was obtained.

(Examples 16 to 18)
Charge rollers 16 to 18 were produced in the same manner as in Example 1 except that the hollow particles 1 were changed to the hollow particles shown in Table 12. In the manufactured charging roller, the electrical resistance value measurement of the charging roller, the average particle diameter of the hollow particles, the measurement of the C set amount, and the evaluation of the C set image were performed in the same manner as in Example 1. The results are shown in Table 12. In Examples 16 to 18, only a slight C set image was observed in a part of the image, and an overall good image was obtained.

(Examples 19 to 21)
Charge rollers 19 to 21 were produced in the same manner as in Example 15 except that the hollow particles 1 were changed to the hollow particles shown in Table 12. In the manufactured charging roller, the electrical resistance value measurement of the charging roller, the average particle diameter of the hollow particles, the measurement of the C set amount, and the evaluation of the C set image were performed in the same manner as in Example 1. The results are shown in Table 12. In Examples 19 to 21, only a slight C set image was observed in a part of the image, and an overall good image was obtained.

(Examples 22 to 24)
Charge rollers 22 to 24 were produced in the same manner as in Example 1 except that the hollow particles 1 were changed to the hollow particles shown in Table 12. In the manufactured charging roller, the electrical resistance value measurement of the charging roller, the average particle diameter of the hollow particles, the measurement of the C set amount, and the evaluation of the C set image were performed in the same manner as in Example 1. The results are shown in Table 12. In Examples 22 to 24, only a slight C set image was observed in a part of the image, and an overall good image was obtained.

(Example 25)
A charging roller 25 was produced in the same manner as in Example 15 except that the hollow particles 1 were changed to the hollow particles shown in Table 12. In the manufactured charging roller 25, the electrical resistance value measurement of the charging roller, the average particle diameter of the hollow particles, the measurement of the C set amount, and the evaluation of the C set image were performed in the same manner as in Example 1. The results are shown in Table 12. In Example 25, only a slight C set image was recognized in a part of the image, and an overall good image was obtained.

(Examples 26 to 29)
Charge rollers 26 to 29 were produced in the same manner as in Example 1 except that the hollow particles 1 were changed to the hollow particles shown in Table 12. In the manufactured charging roller, the electrical resistance value measurement of the charging roller, the average particle diameter of the hollow particles, the measurement of the C set amount, and the evaluation of the C set image were performed in the same manner as in Example 1. The results are shown in Table 12. In Examples 26 to 28, only a slight C set image was observed in a part of the image, and an overall good image was obtained.
In Example 29, a C set image was recognized at a part of the image at the pitch of the charging roller, but an image having no practical problem was obtained.

(Example 30)
A charging roller 30 was produced in the same manner as in Example 15 except that the hollow particles 1 were changed to the hollow particles shown in Table 12. In the manufactured charging roller 30, the measurement of the electric resistance value of the charging roller, the average particle diameter of the hollow particles, the measurement of the C set amount, and the evaluation of the C set image were performed in the same manner as in Example 1. The results are shown in Table 12. In Example 30, a C set image was recognized at a part of the image at the pitch of the charging roller, but an image having no practical problem was obtained.

(Examples 31 to 33)
Charge rollers 31 to 33 were produced in the same manner as in Example 1 except that the hollow particles 1 were changed to the hollow particles shown in Table 12. In the manufactured charging roller, the electrical resistance value measurement of the charging roller, the average particle diameter of the hollow particles, the measurement of the C set amount, and the evaluation of the C set image were performed in the same manner as in Example 1. The results are shown in Table 12. In Examples 31 to 33, a C set image was recognized at a part of the image at the pitch of the charging roller, but an image having no practical problem was obtained.

(Comparative Example 1)
In preparing the compound for the elastic layer, first, the materials shown in Table 10 were kneaded for 15 minutes in a closed mixer adjusted to 50 ° C. to prepare a raw material compound.

  With respect to 141 parts by mass of this raw material compound, the materials listed in Table 11 were blended and kneaded for 15 minutes in a two-roll machine cooled to 20 ° C. to obtain an elastic layer compound.

  A charging roller 34 was produced in the same manner as in Example 1 except that this elastic layer compound was used. In the manufactured charging roller 34, the electrical resistance value measurement of the charging roller, the average particle diameter of the hollow particles, the measurement of the C set amount, and the evaluation of the C set image were performed in the same manner as in Example 1. The results are shown in Table 12. In Comparative Example 1, streak-like C set images were conspicuous, and deterioration in image quality was observed.

(Comparative Example 2)
A charging roller 35 was produced in the same manner as in Example 15 except that the hollow particles 1 were changed to silicone rubber hollow particles. In the manufactured charging roller 35, the electrical resistance value measurement of the charging roller, the average particle diameter of the hollow particles, the measurement of the C set amount, and the evaluation of the C set image were performed in the same manner as in Example 1. The results are shown in Table 12.
In Comparative Example 2, the streak-shaped C set image was conspicuous, and the deterioration of the image quality was recognized.
As described above, the charging roller made of the conductive member of the present invention is preferably incorporated in an electrophotographic apparatus or a process cartridge because the generation of a C set image after being left in a high temperature and high humidity environment is suppressed.

DESCRIPTION OF SYMBOLS 1 Conductive base | substrate 2 Elastic layer 3 Surface layer 4 Electrophotographic photoreceptor 5 Charging member (charging roller)
6 Developing roller 7 Print medium 8 Transfer roller 9 Fixing unit 10 Cleaning blade 11 Exposure 12 Pre-charging exposure device 13 Elastic regulating blade 14 Toner supply rollers 18, 19, 20 Power supply 21 Intermediate layer 22 Second intermediate layer 30 Toner seal 32 Cylinder Shape metal 33 Bearing 34 Stabilizing power supply 35 Ammeter 40 Extruder 41 Crosshead 42 Feed roll 43 Charging member preform 44 Cavity

Claims (7)

A conductive member having a conductive substrate and an elastic layer,
The elastic layer contains ion conductive rubber and hollow particles,
The conductive member, wherein the hollow particles have a shell containing a resin having a unit derived from ethylene oxide.   The conductive member according to claim 1, wherein the shell further contains a quaternary ammonium salt or an organic acid lithium salt.   The conductive member according to claim 1, wherein the quaternary ammonium salt has a structure having perchloric acid. The resin is polyether urethane or polyether ester amide, and
The conductive member according to any one of claims 1 to 3, wherein the content of units derived from ethylene oxide in the resin is 20% by weight or more and 90% by weight or less. The ion conductive rubber is
A copolymer consisting of epichlorohydrin and ethylene oxide, a copolymer consisting of epichlorohydrin, ethylene oxide and allyl glycidyl ether, a copolymer consisting of ethylene oxide, propylene oxide and allyl glycidyl ether, and a group consisting of polyether urethane The conductive member according to claim 1, wherein the number is at least one.   6. A process cartridge in which the conductive member according to claim 1 is at least integrated with a member to be charged and is detachably attached to an electrophotographic apparatus main body.   An electrophotographic apparatus comprising the conductive member according to claim 1.

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