Conductive roll for electrophotographic apparatus

Abstract

To provide a conductive roll for an electrophotographic apparatus in which image defects caused by core metal corrosion and bleed-out of ionic conductive agents are suppressed.SOLUTION: There is provided a conductive roll for an electrophotographic apparatus 10, including at least: a metal shaft 12; an elastic layer 14 disposed outside the outer peripheral surface of the shaft 12; and a surface layer 16 disposed outside the outer peripheral surface of the elastic layer 14, the elastic layer 14 including a polymer containing halogen atoms and an ionic conductive agent formed of at least one type selected from the group consisting of a sulfonium salt, an ammonium salt, and a phosphonium salt, and a region from the outer peripheral surface of the shaft 12 to inside the elastic layer 14 containing a compound having an epoxy group and an ester group.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a conductive roll for electrophotographic equipment that is suitably used in electrophotographic equipment such as copying machines, printers, and facsimiles that employ an electrophotographic system. [Background technology]

[0002] Electrophotographic devices such as copiers, printers, and facsimiles that employ electrophotography typically incorporate a photosensitive drum, around which are arranged roll-shaped conductive members such as a charging roll, a developing roll, a transfer roll, and a toner supply roll, as well as dirt removal members such as a cleaning blade, and belt-shaped conductive members such as a transfer belt and a fixing belt. Copying and printing using this type of electrophotographic device is performed by forming an original image as an electrostatic latent image on the photosensitive drum, adhering toner to the electrostatic latent image to form a toner image, and transferring the toner image to copy paper.

[0003] Conductive rolls for electrophotographic devices are known to have a shaft composed of a core or other material, an elastic layer formed on the outer surface of the shaft, and a surface layer formed on the outer surface of the elastic layer. Conductive rolls are molded using mold molding or assembly molding. In mold molding, the rubber in the elastic layer is tightly attached to the core by utilizing the contraction of the rubber during vulcanization. In assembly molding, hollow rubber with an inner diameter smaller than the core diameter is extruded and assembled in a later process. Conductive rolls are sometimes bonded using adhesives to ensure tight adhesion between the core and the rubber in the elastic layer. Hydrin rubber is sometimes used as the rubber material for the elastic layer of conductive rolls to reduce resistance. Ionic conductive agents are also sometimes used as conductive agents. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent No. 7319907 Summary of the Invention [Problem to be solved by the invention]

[0005] When hydrin rubber is used in the elastic layer of a conductive roll, chlorine atoms can be liberated from the hydrin rubber and react with moisture in the rubber to generate hydrochloric acid. If the generated hydrochloric acid reaches pinholes on the core, the core corrodes. Corrosion of the core can cause changes in the roll shape and resistance, potentially resulting in image defects. Furthermore, ionic conductive agents lower the pH in the rubber. When an ionic conductive agent is used in conjunction with hydrin rubber in the elastic layer of a conductive roll, it lowers the pH in the rubber, facilitating the progress of core corrosion by hydrochloric acid. Furthermore, ionic conductive agents are prone to bleed-out due to polarization when electricity is applied. This can lead to increased resistance and potentially resulting in image defects.

[0006] The problem to be solved by the present invention is to provide a conductive roll for electrophotographic equipment that can suppress image defects due to core metal corrosion and bleeding out of ion conductive agents. [Means for solving the problem]

[0007] The conductive roll for electrophotographic equipment according to the present invention comprises at least a metal shaft and an elastic layer disposed on the outer circumferential surface of the shaft, the elastic layer containing a polymer containing a halogen atom and an ionic conductive agent composed of one or more of sulfonium salts, ammonium salts and phosphonium salts, and further containing a compound having an epoxy group and an ester group within a range extending from the outer circumferential surface of the shaft to the inside of the elastic layer.

[0008] The shaft and the elastic layer are bonded via an adhesive layer, and one or both of the elastic layer and the adhesive layer may contain the compound having an epoxy group and an ester group. In this case, the adhesive layer may contain the compound having an epoxy group and an ester group. Alternatively, the elastic layer may contain the compound having an epoxy group and an ester group. The polymer containing a halogen atom may be hydrin rubber. When the adhesive layer contains the compound having an epoxy group and an ester group, the content of the compound having an epoxy group and an ester group may be 0.004 to 15 parts by mass per 100 parts by mass of the binder in the adhesive layer. When the elastic layer contains the compound having an epoxy group and an ester group, the content of the compound having an epoxy group and an ester group may be 0.004 to 15 parts by mass per 100 parts by mass of the polymer containing a halogen atom in the elastic layer. The content of the ion conductive agent may be 0.2 to 6.5 parts by mass per 100 parts by mass of the polymer containing a halogen atom. The compound having an epoxy group and an ester group preferably has a weight average molecular weight Mw of 5,000 to 150,000.The compound having an epoxy group and an ester group preferably has an aromatic ring.

[0009] In the conductive roll for electrophotographic equipment according to the present invention, the shaft and the elastic layer may be directly bonded to each other, and the elastic layer may contain the compound having an epoxy group and an ester group.

[0010] (1) The conductive roll for electrophotographic equipment according to the present invention comprises at least a metal shaft and an elastic layer disposed on the outer periphery of the shaft, the elastic layer containing a polymer containing a halogen atom and an ionic conductive agent composed of one or more of sulfonium salts, ammonium salts and phosphonium salts, and a compound having an epoxy group and an ester group is contained within the elastic layer from the outer periphery of the shaft to the inside of the elastic layer.

[0011] (2) In the above (1), the shaft body and the elastic layer are bonded via an adhesive layer, and one or both of the elastic layer and the adhesive layer may contain a compound having an epoxy group and an ester group.

[0012] (3) In the above (1) or (2), the polymer containing halogen atoms may be a hydrin rubber.

[0013] (4) In the above (2), the adhesive layer may contain the compound having an epoxy group and an ester group.

[0014] (5) In the above (2), the elastic layer may contain the compound having an epoxy group and an ester group.

[0015] (6) In the above (4), the content of the compound having an epoxy group and an ester group may be 0.004 parts by mass or more and 15 parts by mass or less per 100 parts by mass of the binder in the adhesive layer.

[0016] (7) In the above (5), the content of the compound having an epoxy group and an ester group may be 0.004 parts by mass or more and 15 parts by mass or less per 100 parts by mass of the polymer containing a halogen atom in the elastic layer.

[0017] (8) In any one of the above (1) to (7), the content of the ion conductive agent may be 0.2 parts by mass or more and 6.5 parts by mass or less per 100 parts by mass of the polymer containing a halogen atom.

[0018] (9) In any one of the above (1) to (8), the weight average molecular weight Mw of the compound having an epoxy group and an ester group may be 5,000 or more and 150,000 or less.

[0019] (10) In any one of the above (1) to (9), the compound having an epoxy group and an ester group may have an aromatic ring.

[0020] (11) In the above (1), the shaft and the elastic layer may be directly bonded to each other, and the elastic layer may contain the compound having an epoxy group and an ester group. [Effects of the Invention]

[0021] The conductive roll for electrophotographic devices according to the present invention comprises at least a metal shaft and an elastic layer disposed on the outer circumferential surface of the shaft. When the elastic layer contains a polymer containing a halogen atom and an ionic conductive agent composed of one or more of a sulfonium salt, an ammonium salt, and a phosphonium salt, the conductive roll further comprises a compound having an epoxy group and an ester group disposed within the elastic layer from the outer circumferential surface of the shaft. The compound having an epoxy group and an ester group captures acid generated by the halogen atom, thereby preventing the acid from reaching the metal shaft. Furthermore, the compound having an epoxy group and an ester group immobilizes the ionic conductive agent, thereby suppressing a decrease in pH caused by the ionic conductive agent and the progression of corrosion of a core metal caused by acid. This suppresses core metal corrosion and image defects. Furthermore, the compound having an epoxy group and an ester group immobilizes the ionic conductive agent, thereby suppressing bleed-out of the ionic conductive agent and resulting image defects.

[0022] In either of the configurations where the shaft body and the elastic layer are bonded via an adhesive layer, and one or both of the elastic layer and the adhesive layer contain the compound having an epoxy group and an ester group, or where the shaft body and the elastic layer are bonded directly, and the elastic layer contains the compound having an epoxy group and an ester group, image defects due to core metal corrosion and bleeding out of the ionic conductive agent are suppressed as described above.

[0023] When the polymer containing halogen atoms is a hydrin rubber, chlorine atoms are liberated from the hydrin rubber, which tends to cause core metal corrosion. However, even in this case, the core metal corrosion is suppressed, and image defects due to core metal corrosion are suppressed.

[0024] Furthermore, by including the compound having an epoxy group and an ester group in the adhesive layer, it is possible to effectively capture acids caused by halogen atoms. In addition, it is possible to effectively immobilize the ionic conductive agent. Furthermore, by including the compound having an epoxy group and an ester group in the elastic layer, it is possible to effectively capture acids caused by halogen atoms. In addition, it is possible to effectively immobilize the ionic conductive agent.

[0025] When the adhesive layer contains the compound having an epoxy group and an ester group, if the content of the compound having an epoxy group and an ester group is 0.004 parts by mass or more and 15 parts by mass or less per 100 parts by mass of the binder of the adhesive layer, the acid capturing effect due to halogen atoms and the immobilization effect of the ion conductive agent are excellent, and an increase in resistance due to the compound is easily suppressed.

[0026] When the elastic layer contains the compound having an epoxy group and an ester group, if the content of the compound having an epoxy group and an ester group is 0.004 parts by mass or more and 15 parts by mass or less per 100 parts by mass of the polymer containing a halogen atom in the elastic layer, the acid capturing effect due to the halogen atom and the immobilization effect of the ionic conductive agent are excellent, and an increase in resistance due to the compound is easily suppressed.

[0027] When the content of the ionic conductive agent is 0.2 parts by mass or more and 6.5 parts by mass or less per 100 parts by mass of the polymer containing halogen atoms, the effect of reducing resistance is excellent and bleeding out of the ionic conductive agent is easily suppressed.

[0028] When the weight-average molecular weight Mw of the compound having an epoxy group and an ester group is 5,000 or more and 150,000 or less, a decrease in the fixing effect of the ion conductive agent due to a lack of ester groups is easily suppressed, and an increase in resistance due to the compound is easily suppressed.

[0029] When the compound having an epoxy group and an ester group has an aromatic ring, the immobilizing effect of the ion conductive agent is easily prevented from decreasing. [Brief explanation of the drawings]

[0030] [Figure 1] 1A is a schematic external view of a conductive roller for electrophotographic equipment according to one embodiment of the present invention, and FIG. 1B is a cross-sectional view taken along line AA thereof. [Figure 2] 1A is a schematic view of the appearance of a conductive roller for electrophotographic equipment according to another embodiment of the present invention, and FIG. 1B is a cross-sectional view thereof taken along line BB. DETAILED DESCRIPTION OF THE INVENTION

[0031] The conductive roll for electrophotographic equipment (hereinafter sometimes simply referred to as conductive roll) according to the present invention will be described in detail. Fig. 1 shows a schematic external view (a) of the conductive roll for electrophotographic equipment according to one embodiment of the present invention, and a cross-sectional view (b) of the same taken along line AA. The conductive roll includes at least a metal shaft and an elastic layer disposed on the outer circumferential surface of the shaft.

[0032] The conductive roll 10 comprises a shaft 12, an adhesive layer 18 formed on the outer peripheral surface of the shaft 12, an elastic layer 14 formed on the outer peripheral surface of the adhesive layer 18, and a surface layer 16 formed on the outer peripheral surface of the elastic layer 14. The elastic layer 14 is a layer (base layer) that forms the base of the conductive roll 10. The surface layer 16 is a layer that appears on the surface of the conductive roll 10. The adhesive layer 18 is disposed between the shaft 12 and the elastic layer 14 and is in contact with both. The adhesive layer 18 functions as a layer that bonds the shaft 12 and the elastic layer 14. The shaft 12 and the elastic layer 14 are bonded via the adhesive layer 18.

[0033] Generally, the shaft 12 may be made of any conductive material, and the material is not limited in this respect. However, in the present invention, the shaft 12 is made of a metallic material. The shaft 12 may be made of only a base material made of a metallic material, or may have one or more metal layers formed on the surface of the base material by plating or the like. In this case, the metal layer is formed to improve rust resistance and adhesion to the adhesive layer 18. From the viewpoint of cost, it is preferable that the shaft 12 be made of only a base material. However, from the viewpoint of excellent rust resistance and excellent adhesion to the adhesive layer 18, it is preferable that the shaft 12 have one or more metal layers on the surface of the base material.

[0034] Examples of the metal of the base material include iron and stainless steel. From the viewpoint of cost, iron is preferred as the metal of the base material. The metal layer formed on the surface of the base material is made of a metal having electrical conductivity. Examples of the metal of such a metal layer include nickel. From the viewpoints of workability, adhesion, etc., the metal layer formed on the surface of the base material is preferably formed by plating. There are electroless plating and electrolytic plating, but electroless plating is preferred from the viewpoints of excellent film thickness uniformity and fewer defects such as pinholes.

[0035] The thickness of the metal layer formed on the surface of the base material is preferably relatively thick (specifically, 10 μm or more) from the viewpoint of excellent rust prevention and excellent adhesion to the adhesive layer 18, but since this increases the cost, from the viewpoint of cost, it is preferable that the thickness be 3 μm or less.

[0036] The shape of the shaft body 12 is not particularly limited as long as it can be a shape that can form a shaft body, and it may be a solid round bar shape or a cylindrical shape with a hollowed-out interior.

[0037] The adhesive layer 18 is made of an adhesive composition containing an adhesive component (binder component). Examples of the adhesive component include phenolic resin adhesives, epoxy resin adhesives, nitrile rubber adhesives, acrylic resin adhesives, polyurethane adhesives, styrene-butadiene adhesives, and natural rubber adhesives. Only one of these adhesive components may be used, or two or more of these adhesive components may be used in combination.

[0038] The adhesive component of the adhesive composition is preferably a vulcanizing adhesive, from the viewpoint that it can be cured by heat and pressure during vulcanization of the elastic layer 14 and function as the adhesive layer 18. Examples of the vulcanizing adhesive include phenolic resin adhesives, epoxy resin adhesives, and nitrile rubber adhesives, among the adhesive components described above. Only one of these may be used, or two or more of these may be used in combination.

[0039] The adhesive composition may contain, as needed, a conductive agent (electronic conductive agent, ionic conductive agent) to impart conductivity, and may also contain one or more additives such as a vulcanizing agent (crosslinking agent), vulcanization accelerator, vulcanization aid (crosslinking aid), extender, reinforcing agent, processing aid, antioxidant, plasticizer, UV absorber, and lubricant.

[0040] The viscosity of the adhesive composition can be adjusted by using a solvent, taking into consideration the application properties. Examples of the solvent include methyl ethyl ketone (MEK) and methyl isobutyl ketone (MIBK).

[0041] The thickness of the adhesive layer 18 is not particularly limited. It can be set to, for example, 1 μm or more and 100 μm or less. The thickness of the adhesive layer 18 is more preferably 3 μm or more and 50 μm or less, and even more preferably 5 μm or more and 10 μm or less. The volume resistivity of the adhesive layer 18 is not particularly limited, but from the viewpoint of excellent conductivity, it is preferably 1.0×10 2 ~5.0×10 5 It is preferable that the resistance is in the range of Ω·cm.

[0042] The elastic layer 14 is made of a conductive rubber composition containing a polymer containing halogen atoms and an ionic conductive agent.

[0043] The polymer containing halogen atoms is contained as the main component of the rubber component of the conductive rubber composition. The main component is 50% by mass or more, more preferably 70% by mass or more, or 90% by mass or more. Examples of the polymer containing halogen atoms include hydrin rubber, chloroprene rubber, chlorinated butyl rubber, and chlorosulfonated polyethylene rubber. Of these, hydrin rubber is more preferred from the viewpoint of low resistance.

[0044] Examples of hydrin rubbers include epichlorohydrin homopolymer (CO), epichlorohydrin-ethylene oxide copolymer (ECO), epichlorohydrin-allyl glycidyl ether copolymer (GCO), and epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer (GECO).

[0045] The ionic conductive agent is composed of one or more of sulfonium salts, ammonium salts, and phosphonium salts. Of these, sulfonium salts and ammonium salts are more preferred from the viewpoint of thermal stability.

[0046] Examples of the cations of sulfonium salts, ammonium salts, and phosphonium salts include those having one or more alkyl or aryl groups having about 1 to 18 carbon atoms (e.g., methyl, ethyl, propyl, butyl, hexyl, octyl, decyl, phenyl, and xylyl groups). The alkyl or aryl groups of the cations of sulfonium salts, ammonium salts, and phosphonium salts are particularly preferably those having 1 to 10 carbon atoms. Examples of the anions of sulfonium salts, ammonium salts, and phosphonium salts include F - ,Cl - ,Br - ,I - Halogen ions such as ClO4 - , BF4 - , PF6 - , SO42- , HSO4 - , C2H5SO4 - , CF3COO - , CF3SO3 - , (CF3SO2)2N - , (CF3CF2SO2)2N - , CF3(CF2)3SO3 - , (CF3SO2)3C - , CF3(CF2)2COO - Examples of anions of sulfonium salts, ammonium salts, and phosphonium salts include ClO4 - , PF6 - , (CF3SO2)2N - , CF3SO3 - etc. are more preferable.

[0047] The content of the ionic conductive agent is preferably 0.2 parts by mass or more per 100 parts by mass of the polymer containing halogen atoms, from the viewpoint of achieving an excellent effect of reducing resistance. It is more preferably 0.5 parts by mass or more, and even more preferably 1.0 part by mass or more. Furthermore, from the viewpoint of easily suppressing bleed-out of the ionic conductive agent, it is preferably 6.5 parts by mass or less per 100 parts by mass of the polymer containing halogen atoms, more preferably 6.0 parts by mass or less, and even more preferably 5.0 parts by mass or less.

[0048] The conductive rubber composition may contain, in addition to the rubber component, a conductive agent (electronic conductive agent) to enhance conductivity, and may also contain, in addition to the rubber component, one or more additives such as vulcanizing agents (crosslinking agents), vulcanization accelerators, vulcanization aids (crosslinking aids), extenders, reinforcing agents, processing aids, antioxidants, plasticizers, UV absorbers, and lubricants.

[0049] Examples of electronic conductive agents include carbon black, graphite, potassium titanate, iron oxide, conductive titanium oxide, conductive zinc oxide, and conductive tin oxide. Examples of vulcanizing agents (crosslinking agents) include sulfur, peroxides, and hydrosilyl crosslinking agents. Examples of vulcanization aids (crosslinking aids) include zinc oxide, magnesium oxide, and hydrotalcite.

[0050] The thickness of the elastic layer 14 is not particularly limited, but is usually formed to about 0.1 to 10 mm, preferably 1 to 5 mm. From the viewpoint of excellent conductivity, the elastic layer 14 has a volume resistivity of 1.0×10 5 ~5.0×10 8 The elastic layer 14 may be a solid non-foamed material, or a foamed material such as a sponge.

[0051] Here, it is important that the conductive roll 10 contains a compound having an epoxy group and an ester group in the range from the outside of the outer peripheral surface of the shaft 12 to the inside of the elastic layer 14 (i.e., in one or both of the elastic layer 14 and the adhesive layer 18).

[0052] The elastic layer 14 contains a polymer containing halogen atoms, such as hydrin rubber. When halogen atoms are liberated from the polymer containing halogen atoms and react with moisture in the rubber, acids resulting from the halogen atoms, such as hydrochloric acid, may be generated. Acids resulting from halogen atoms can corrode the metal shaft 12. The epoxy groups in the compound react with and capture the acids resulting from halogen atoms, thereby preventing the acids resulting from halogen atoms from reaching the metal shaft 12.

[0053] To achieve low resistance, the elastic layer 14 contains an ionic conductive agent along with a polymer containing halogen atoms. The ionic conductive agent lowers the pH in the rubber, facilitating the corrosion of the metal shaft 12 by the acid caused by the halogen atoms. The ionic conductive agent also tends to bleed out due to polarization when current is applied. The epoxy group of the compound binds to the cations of the ionic conductive agent, thereby immobilizing (capturing) the ionic conductive agent. Furthermore, the ester group of the compound electrostatically adsorbs the cations and anions of the ionic conductive agent due to the strong dipole moment of the ester group, thereby immobilizing (capturing) the ionic conductive agent. This prevents the ionic conductive agent from bleeding out.

[0054] From the viewpoint of achieving a more excellent effect of capturing acids resulting from halogen atoms, it is more preferable that the compound having an epoxy group and an ester group is contained in the adhesive layer 18 or in both the adhesive layer 18 and the elastic layer 14 in the conductive roll 10. On the other hand, from the viewpoint of achieving a more excellent effect of immobilizing (capturing) the ion conductive agent, it is more preferable that the compound having an epoxy group and an ester group is contained in the elastic layer 14 or in both the adhesive layer 18 and the elastic layer 14 in the conductive roll 10.

[0055] When the adhesive layer 18 contains a compound having an epoxy group and an ester group, the content of the compound having an epoxy group and an ester group is preferably 0.004 parts by mass or more relative to 100 parts by mass of the binder in the adhesive layer 18, from the viewpoints of excellent acid scavenging effect due to halogen atoms and excellent effect of immobilizing (scavenging) the ionic conductive agent at the interface between the elastic layer 14 and the adhesive layer 18. It is more preferably 0.01 parts by mass or more, and even more preferably 0.1 parts by mass or more. Furthermore, from the viewpoint of easily suppressing an increase in resistance due to the compound, it is preferably 15 parts by mass or less relative to 100 parts by mass of the binder in the adhesive layer 18. It is more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less.

[0056] When the elastic layer 14 contains a compound having an epoxy group and an ester group, the content of the compound having an epoxy group and an ester group is preferably 0.004 parts by mass or more relative to 100 parts by mass of the polymer containing halogen atoms in the elastic layer 14, from the viewpoints of excellent acid scavenging effect due to halogen atoms and excellent effect of immobilizing (scavenging) the ionic conductive agent. It is more preferably 0.01 parts by mass or more, and even more preferably 0.1 parts by mass or more. Furthermore, from the viewpoint of easily suppressing an increase in resistance due to the compound, it is preferably 15 parts by mass or less relative to 100 parts by mass of the polymer containing halogen atoms in the elastic layer 14. It is more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less.

[0057] The epoxy group- and ester group-containing compound preferably has a weight-average molecular weight Mw of 5,000 or more, more preferably 7,000 or more, and even more preferably 9,000 or more, from the viewpoint of easily suppressing a decrease in the fixing effect of the ion conductive agent due to a lack of ester groups. On the other hand, the weight-average molecular weight Mw is preferably 150,000 or less, more preferably 100,000 or less, and even more preferably 50,000 or less, from the viewpoint of easily suppressing an increase in resistance due to the compound.

[0058] The compound having an epoxy group and an ester group may preferably have an aromatic ring, which is effective in suppressing bleed-out by utilizing steric hindrance, and tends to suppress a decrease in the immobilization effect of the ion conductive agent.

[0059] The material of the surface layer 16 is not particularly limited, and examples thereof include polyamide (nylon), acrylic, urethane, silicone, and fluorine-based polymers. These polymers may be modified. Examples of the modified group include an N-methoxymethyl group, a silicone group, and a fluorine group.

[0060] To impart conductivity to the surface layer 16, a conductive agent such as carbon black, graphite, conductive titanium oxide, conductive zinc oxide, conductive tin oxide, or an ionic conductive agent (ammonium salt, phosphonium salt, borate, surfactant, etc.) may be appropriately added. Furthermore, various additives such as a crosslinking agent for the polymer component, a leveling agent, or a surface modifier may also be appropriately added as needed. Furthermore, to ensure surface roughness, roughness-forming particles may or may not be added to the surface layer 16.

[0061] The thickness of the surface layer 16 is not particularly limited, but is preferably in the range of 0.01 to 100 μm, more preferably in the range of 0.1 to 20 μm, and even more preferably in the range of 0.3 to 10 μm. The volume resistivity of the surface layer 16 is preferably 10 7 ~1012 Ω·cm, more preferably 10 8 ~10 11 Ω·cm, more preferably 10 9 ~10 10 It is in the range of Ω·cm.

[0062] The conductive roll 10 can be produced by forming an adhesive layer 18 on the outer peripheral surface of the shaft 12, forming an elastic layer 14 on the outer peripheral surface of the adhesive layer 18, and forming a surface layer 16 on the outer peripheral surface of the elastic layer 14.

[0063] The adhesive layer 18 can be formed by applying the adhesive composition onto the outer peripheral surface of the shaft 12 and then performing a predetermined heat treatment. The heating temperature in the heat treatment is preferably 150 to 250° C. The heating time is preferably 30 to 60 minutes.

[0064] The elastic layer 14 can be formed by molding the conductive rubber composition into a layer. The conductive rubber composition can be molded by extrusion molding or molding. The conductive rubber composition is crosslinked and cured by heating during extrusion molding or molding.

[0065] The surface layer 16 can be formed by applying a surface layer-forming composition to the outer peripheral surface of the elastic layer 14, followed by heat treatment as necessary. The surface layer-forming composition may contain an appropriate solvent, such as an organic solvent such as methyl ethyl ketone (MEK), toluene, acetone, ethyl acetate, butyl acetate, methyl isobutyl ketone (MIBK), THF, or DMF, or a water-soluble solvent such as methanol or ethanol, in order to adjust the viscosity. Various coating methods, such as roll coating, dipping, and spray coating, can be used for the coating method.

[0066] The conductive roll 10 having the above configuration comprises a metal shaft 12, an adhesive layer 18 formed on the outer peripheral surface of the shaft 12, and an elastic layer 14 formed on the outer peripheral surface of the adhesive layer 18. The elastic layer 14 contains a polymer containing a halogen atom and an ionic conductive agent composed of one or more of a sulfonium salt, an ammonium salt, and a phosphonium salt. In this case, one or both of the elastic layer 14 and the adhesive layer 18, i.e., the area outside the outer peripheral surface of the shaft 12 and into the elastic layer 14, contains a compound having an epoxy group and an ester group.

[0067] The compound having an epoxy group and an ester group in the elastic layer 14 or the adhesive layer 18 captures acid resulting from halogen atoms in the halogen-containing polymer in the elastic layer 14, preventing the acid from reaching the metal shaft 12. Furthermore, the compound having an epoxy group and an ester group in the elastic layer 14 or the adhesive layer 18 immobilizes the ionic conductive agent in the elastic layer 14, thereby suppressing a decrease in pH due to the ionic conductive agent and the progression of corrosion of the metal shaft 12 due to acid. This suppresses corrosion of the metal shaft 12 and image defects. Furthermore, the compound having an epoxy group and an ester group in the elastic layer 14 or the adhesive layer 18 immobilizes the ionic conductive agent in the elastic layer 14, thereby suppressing bleed-out of the ionic conductive agent and the resulting image defects.

[0068] The conductive roll 10 includes a shaft 12, an adhesive layer 18, an elastic layer 14, and a surface layer 16 in this order, but the conductive roll for electrophotographic equipment according to the present invention is not limited to this configuration. For example, the conductive roll may have a configuration without the adhesive layer 18.

[0069] 2A is a schematic view of the appearance of a conductive roller for an electrophotographic device according to another embodiment of the present invention, and FIG. 2B is a cross-sectional view taken along line BB of the conductive roller. The conductive roller includes at least a metal shaft and an elastic layer disposed on the outer circumferential surface of the shaft.

[0070] The conductive roll 20 comprises a shaft 12, an elastic layer 14 formed on the outer peripheral surface of the shaft 12, and a surface layer 16 formed on the outer peripheral surface of the elastic layer 14. The conductive roll 20 comprises the shaft 12, the elastic layer 14, and the surface layer 16, in this order. In the conductive roll 20, the elastic layer 14 is in contact with both the shaft 12 and the surface layer 16. The conductive roll 20 differs from the conductive roll 10 only in the presence or absence of an adhesive layer 18, and is otherwise similar to the conductive roll 10, so a description of the overlapping parts will be omitted.

[0071] It is important that the conductive roll 20 contains a compound having an epoxy group and an ester group in the area extending from the outer peripheral surface of the shaft 12 to the inside of the elastic layer 14 (i.e., the elastic layer 14). The compound having an epoxy group and an ester group is as described above.

[0072] The conductive roll 20 having the above configuration comprises a metal shaft 12 and an elastic layer 14 formed on the outer circumferential surface of the shaft 12. The elastic layer 14 contains a polymer containing halogen atoms and an ionic conductive agent composed of one or more of sulfonium salts, ammonium salts, and phosphonium salts. In this case, the elastic layer 14, i.e., the area from the outer circumferential surface of the shaft 12 to the inside of the elastic layer 14, contains a compound having an epoxy group and an ester group.

[0073] The compound having an epoxy group and an ester group in the elastic layer 14 captures acid resulting from halogen atoms in the halogen-containing polymer in the elastic layer 14, thereby preventing the acid from reaching the metal shaft 12. Furthermore, the compound having an epoxy group and an ester group in the elastic layer 14 immobilizes the ionic conductive agent in the elastic layer 14, thereby suppressing a decrease in pH due to the ionic conductive agent and the progression of corrosion of the metal shaft 12 due to acid. This suppresses corrosion of the metal shaft 12 and image defects. Furthermore, the compound having an epoxy group and an ester group in the elastic layer 14 immobilizes the ionic conductive agent in the elastic layer 14, thereby suppressing bleed-out of the ionic conductive agent and the resulting image defects.

[0074] The conductive rolls 10 and 20 are provided with a surface layer 16 on the outer periphery of the elastic layer 14 for reasons such as protecting the surface and imparting electrical properties, but the conductive roll for electrophotographic equipment according to the present invention is not limited to this configuration. For example, the conductive rolls 10 and 20 may be configured without the surface layer 16. Instead of the surface layer 16, the surface of the elastic layer 14 may be subjected to a surface modification treatment. Examples of surface modification methods include a method of irradiating with UV or electron beams, and a method of contacting the elastic layer 14 with a surface modifier capable of reacting with unsaturated bonds or halogens, such as a compound containing a reactive group such as an isocyanate group, a hydrosilyl group, an amino group, a halogen group, or a thiol group.

[0075] The conductive roll according to the present invention can be used as a conductive roll such as a charging roll, a developing roll, a transfer roll, or a toner supply roll in electrophotographic equipment such as a copying machine, a printer, or a facsimile machine. [Example]

[0076] The present invention will be described in detail below using examples and comparative examples.

[0077] Example 1 <Preparation of Adhesive Composition> For 100 parts by mass of phenolic resin adhesive ("Metalock UB" manufactured by Toyo Kagaku Kenkyusho) as a binder, <1> An adhesive composition was obtained by blending 15 parts by mass of the above.

[0078] <Preparation of Conductive Rubber Composition> 100 parts by mass of epichlorohydrin rubber (ECO) ["Hydrin T3106" manufactured by Nippon Zeon Co., Ltd.], 0.5 parts by mass of sulfur [manufactured by Tsurumi Chemical Industry Co., Ltd.] as a vulcanizing agent, 5.0 parts by mass of zinc oxide type 2 [manufactured by Mitsui Mining & Smelting Co., Ltd.] as a vulcanization aid, and 10.0 parts by mass of hydrotalcite [manufactured by Kyowa Chemical Industry Co., Ltd., product name "DHT4A"], 1.0 part by mass of vulcanization accelerator A [manufactured by Sanshin Chemical Industry Co., Ltd., product name "Suncerer CZ"], 1.0 part by mass of vulcanization accelerator B [manufactured by Ouchi Shinko Chemical Industry Co., Ltd., product name "Accel TBT"], ion conductive agent <1> 3.0 parts by mass of the hydroxybenzoate was mixed in a kneader to obtain a conductive rubber composition.

[0079] <Preparation of Composition for Forming Surface Layer> A surface layer forming composition was prepared by mixing 100 parts by mass of N-methoxymethylated nylon ("EF30T" manufactured by Nagase ChemteX), 60 parts by mass of conductive tin oxide ("S-2000" manufactured by Mitsubishi Materials), 1 part by mass of citric acid, and 300 parts by mass of methanol.

[0080] <Preparation of conductive roll> The adhesive composition was applied to the outer periphery of a nickel-plated iron core (φ6 mm) and dried. The core with the adhesive composition applied was then set in a pipe-shaped molding die, and the conductive rubber composition was poured into the die. The die was then heated at 180°C for 30 minutes to vulcanize and cure the adhesive composition and conductive rubber composition. The thickness of the adhesive layer was adjusted to 10 μm, and the thickness of the elastomer layer was adjusted to 3 mm. Next, the surface of the elastomer layer was roll-coated with a surface layer-forming composition and heated at 120°C for 50 minutes to form a 10 μm-thick surface layer around the periphery of the elastomer layer. This produced a conductive roll.

[0081] Examples 2 to 4 In preparing the adhesive composition, the compound <1> A conductive roll was produced in the same manner as in Example 1, except that the blending amount of was changed.

[0082] (Examples 5 to 8) A conductive roll was produced in the same manner as in Example 1, except that the type and amount of compound used in preparing the adhesive composition were changed.

[0083] Example 9 In preparing the adhesive composition, the compound <1> In preparing the conductive rubber composition, the rubber type was changed from hydrin rubber to chloroprene rubber, and the ionic conductive agent <1> A conductive roll was produced in the same manner as in Example 1, except that the blending amount of was changed. Chloroprene rubber [Showa Denko "Shopren GW"]

[0084] (Examples 10 to 11) In preparing the adhesive composition, the compound <1> A conductive roll was produced in the same manner as in Example 1, except that the compounding amount of was changed and the type of ionic conductive agent was changed in the preparation of the conductive rubber composition.

[0085] Examples 12 to 15 In preparing the adhesive composition, the compound <1> In preparing the conductive rubber composition, the compounding amount of the ionic conductive agent is changed. <1> A conductive roll was produced in the same manner as in Example 1, except that the blending amount of was changed.

[0086] Example 21 <Preparation of Adhesive Composition> A phenolic resin adhesive ("Metalock UB" manufactured by Toyo Kagaku Kenkyusho) was used as the adhesive composition.

[0087] <Preparation of Conductive Rubber Composition> 100 parts by mass of epichlorohydrin rubber (ECO) ["Hydrin T3106" manufactured by Nippon Zeon Co., Ltd.], 0.5 parts by mass of sulfur [manufactured by Tsurumi Chemical Industry Co., Ltd.] as a vulcanizing agent, 5.0 parts by mass of zinc oxide type 2 [manufactured by Mitsui Mining & Smelting Co., Ltd.] as a vulcanization aid, and 10.0 parts by mass of hydrotalcite [manufactured by Kyowa Chemical Industry Co., Ltd., product name "DHT4A"], 1.0 part by mass of vulcanization accelerator A [manufactured by Sanshin Chemical Industry Co., Ltd., product name "Suncerer CZ"], 1.0 part by mass of vulcanization accelerator B [manufactured by Ouchi Shinko Chemical Industry Co., Ltd., product name "Accel TBT"], ion conductive agent <1> 3.0 parts by mass of a compound <1> and 15 parts by mass of the above were kneaded in a kneader to obtain a conductive rubber composition.

[0088] <Preparation of Composition for Forming Surface Layer> A surface layer forming composition was prepared by mixing 100 parts by mass of N-methoxymethylated nylon ("EF30T" manufactured by Nagase ChemteX), 60 parts by mass of conductive tin oxide ("S-2000" manufactured by Mitsubishi Materials), 1 part by mass of citric acid, and 300 parts by mass of methanol.

[0089] <Preparation of conductive roll> The adhesive composition was applied to the outer periphery of a nickel-plated iron core (φ6 mm) and dried. The core with the adhesive composition applied was then set in a pipe-shaped molding die, and the conductive rubber composition was poured into the die. The die was then heated at 180°C for 30 minutes to vulcanize and cure the adhesive composition and conductive rubber composition. The thickness of the adhesive layer was adjusted to 10 μm, and the thickness of the elastomer layer was adjusted to 3 mm. Next, the surface of the elastomer layer was roll-coated with a surface layer-forming composition and heated at 120°C for 50 minutes to form a 10 μm-thick surface layer around the periphery of the elastomer layer. This produced a conductive roll.

[0090] Examples 22 to 24 In preparing the conductive rubber composition, the compound <1> A conductive roll was produced in the same manner as in Example 21, except that the blending amount of was changed.

[0091] Examples 25 to 28 A conductive roll was produced in the same manner as in Example 21, except that the type and amount of compound used in preparing the conductive rubber composition were changed.

[0092] Examples 29 to 32 A conductive roll was produced in the same manner as in Examples 21 to 24, except that an elastic layer was formed directly on the outer periphery of a nickel-plated iron core without forming an adhesive layer.

[0093] (Comparative Example 1) In preparing the adhesive composition, the compound <1> A conductive roll was produced in the same manner as in Example 1, except that the compounding amount of the ionic conductive agent was changed in the preparation of the conductive rubber composition, and the type and compounding amount of the ionic conductive agent were changed.

[0094] (Comparative Examples 2 to 3) A conductive roll was produced in the same manner as in Example 1, except that the type and amount of compound used in preparing the adhesive composition were changed.

[0095] Comparative Example 4 A conductive roll was produced in the same manner as in Example 1, except that no compound was added in the preparation of the adhesive composition.

[0096] The following materials were prepared as compounds having epoxy groups and ester groups and ion conductive agents. (Compounds having epoxy groups and ester groups) ·Compound <1> : Toa Gosei "ARUFON UG-4040" weight average molecular weight Mw 11,000, contains aromatic ring ·Compound <2> NOF's "Marproof G-1005SA" weight average molecular weight Mw 100,000, contains aromatic rings ·Compound <3> : Toagosei "ARUFON UG-4070" weight average molecular weight Mw 9,700, contains aromatic ring ·Compound <4> NOF's "Marproof G-2050M" weight average molecular weight Mw 200,000, contains aromatic rings ·Compound <5> Toa Gosei "ARUFON UG-4010" weight average molecular weight Mw 2,900, no aromatic ring ·Compound <6> Mitsubishi Chemical "JER1256" weight average molecular weight Mw 50,000, contains aromatic rings ·Compound <7> : Toagosei "ARUFON UH-2170" weight average molecular weight Mw 14,000, contains aromatic ring

[0097] (ionic conductive agent) Ionic conductive agent <1> : Sulfonium salt, Nippon Carlit "PEL-25" (Li·ClO4, Li·CF3SO3) Ionic conductive agent <2> : Ammonium salt, TCI AMERICA "T0676" ((CH3)4N·OH) Ionic conductive agent <3> : Phosphonium salt, TCI AMERICA "H1047" ((n-Bu)3(CH3(CH2) 15 P·Br) Ionic conductive agent <4> : Imidazolium salt, "IL-IM1" manufactured by Koei Chemical

[0098] (Bulging of the roll surface: Corrosion of the core metal) The manufactured conductive roll was left to stand for one month in an environment of 50°C temperature and 95% humidity. When no swelling occurred on the roll surface, it was marked with "◎", when slight swelling occurred but within the acceptable range, it was marked with "○", when swelling occurred at the same level as the current product, it was marked with "△", and when swelling occurred at a level outside the acceptable range, it was marked with "×".

[0099] (Black dot LL: High resistance and uneven discharge) The manufactured conductive roll was installed as a charging roll in a Konica Minolta multifunction printer "bizhub C658," and after printing 2 million sheets in a ruled line mode with a print density of 1% in an environment of 10°C x 10% RH, a halftone image with a print density of 25% was printed. If no black dot images caused by uneven discharge were observed, the result was rated as very good (◎); if slight black dot images were observed but within the acceptable range, the result was rated as good (○); if black dot images were the same as the current product, the result was rated as fair; and if black dot images were clearly observed, the result was rated as poor (×).

[0100] (Fog LL: High resistance, low capacitance, insufficient discharge) The manufactured conductive roll was installed as a charging roll in a Konica Minolta multifunction printer "bizhub C658," and after printing 2 million sheets in a ruled line mode with a print density of 1% in an environment of 10°C x 10% RH, a halftone image with a print density of 25% was printed. If no fogged images due to insufficient discharge were observed, the result was rated as very good (◎); if slight fogged images were observed but within the acceptable range, the result was rated as good (○); if the fogged images were the same as the current model, the result was rated as fair; and if clearly fogged images were observed, the result was rated as poor (×).

[0101] (Bleed) The manufactured conductive roll was installed as a charging roll in a Konica Minolta multifunction printer "bizhub C658," and after printing 2 million sheets in a ruled line mode with a print density of 1% in an environment of 10°C x 10% RH, a halftone image with a print density of 25% was printed. If no bleed-out caused by the ionic conductive agent was observed on the conductive roll surface, the result was rated as very good (◎); if slight bleed-out was observed but within the acceptable range, the result was rated as good (○); if bleed-out was observed at the same level as the current product, the result was rated as fair; and if bleed-out was clearly observed, the result was rated as poor (×).

[0102] [Table 1]

[0103] [Table 2]

[0104] [Table 3]

[0105] [Table 4]

[0106] [Table 5]

[0107] The conductive rolls of Examples 1 to 15 each have a metal shaft, an adhesive layer, and an elastic layer, in this order. The elastic layer contains a polymer containing a halogen atom and an ionic conductive agent selected from sulfonium salts, ammonium salts, and phosphonium salts. The adhesive layer contains a compound having an epoxy group and an ester group. The conductive rolls of Examples 21 to 28 each have a metal shaft, an adhesive layer, and an elastic layer, in this order. The elastic layer contains a polymer containing a halogen atom and an ionic conductive agent selected from sulfonium salts, ammonium salts, and phosphonium salts. The elastic layer contains a compound having an epoxy group and an ester group. The conductive rolls of Examples 29 to 32 each have a metal shaft and an elastic layer, in this order. The elastic layer contains a polymer containing a halogen atom and an ionic conductive agent selected from sulfonium salts, ammonium salts, and phosphonium salts. The elastic layer contains a compound having an epoxy group and an ester group.

[0108] That is, the conductive rolls of Examples 1 to 15 and 21 to 32 each include a metal shaft and an elastic layer, the elastic layer containing a polymer containing a halogen atom and an ionic conductive agent composed of one or more of a sulfonium salt, an ammonium salt, and a phosphonium salt, and a compound having an epoxy group and an ester group is contained in the area extending from the outer peripheral surface of the metal shaft to the inside of the elastic layer. Furthermore, according to the examples, it is clear that swelling of the roll surface, black dots, fogging, and bleeding of the ionic conductive agent are suppressed, and image defects due to core metal corrosion and bleeding of the ionic conductive agent are suppressed.

[0109] In contrast, in Comparative Example 1, the ionic conductive agent in the elastic layer is composed of an imidazolium salt. Due to steric hindrance, the compound having an epoxy group and an ester group in the adhesive layer cannot immobilize the imidazolium salt, and core metal corrosion and bleed-out of the ionic conductive agent cannot be suppressed. In Comparative Example 2, the ionic conductive agent in the elastic layer is a specific type, but the compound in the adhesive layer has an epoxy group but not an ester group. As a result, the ionic conductive agent cannot be immobilized, and bleed-out of the ionic conductive agent cannot be suppressed. In Comparative Example 3, the ionic conductive agent in the elastic layer is a specific type, but the compound in the adhesive layer has an ester group but not an epoxy group. As a result, acid caused by halogen atoms cannot be captured, and core metal corrosion cannot be suppressed. In Comparative Example 4, a compound having an epoxy group and an ester group is not present in the area outside the outer peripheral surface of the metal shaft and into the elastic layer. As a result, acid caused by halogen atoms cannot be captured, and core metal corrosion cannot be suppressed. In Comparative Example 4, the ionic conductive agent cannot be immobilized, and bleed-out of the ionic conductive agent cannot be suppressed.

[0110] Furthermore, Examples 1 to 4 show that when the content of the compound having an epoxy group and an ester group is 0.004 to 15 parts by mass relative to 100 parts by mass of the binder in the adhesive layer, the acid scavenging effect caused by halogen atoms is excellent and the resistance increase (black dot images) caused by the compound is easily suppressed. Similarly, Examples 21 to 24 show that when the content of the compound having an epoxy group and an ester group is 0.004 to 15 parts by mass relative to 100 parts by mass of the polymer containing halogen atoms in the elastic layer, the acid scavenging effect caused by halogen atoms is excellent and the resistance increase (black dot images) caused by the compound is easily suppressed.

[0111] Furthermore, Examples 1, 5 to 8 show that when the weight-average molecular weight Mw of the compound having an epoxy group and an ester group is 5,000 or more and 150,000 or less, the decrease in the fixing effect of the ionic conductive agent due to a lack of ester groups is easily suppressed, and the increase in resistance (fogging) caused by the compound is also easily suppressed.Similarly, Examples 21, 25 to 28 show that when the weight-average molecular weight Mw of the compound having an epoxy group and an ester group is 5,000 or more and 150,000 or less, the decrease in the fixing effect of the ionic conductive agent due to a lack of ester groups is easily suppressed, and the increase in resistance (fogging) caused by the compound is also easily suppressed.

[0112] Furthermore, from Examples 1 and 12 to 15, it can be seen that when the content of the ionic conductive agent is 0.2 parts by mass or more and 6.5 parts by mass or less per 100 parts by mass of the polymer containing halogen atoms, the effect of reducing resistance (fogging suppression) is excellent and bleeding out of the ionic conductive agent due to an increase in the amount is easily suppressed.

[0113] Although the embodiments and examples of the present invention have been described above, the present invention is not limited to the above embodiments and examples, and various modifications are possible within the scope of the invention. [Explanation of symbols]

[0114] 10,20 Conductive roll 12 shaft body 14 Elastic layer 16 Surface layer 18 Adhesive layer

Claims

1. The device comprises at least a metal shaft body and an elastic layer disposed on the outer circumferential surface of the shaft body, the elastic layer includes a polymer containing a halogen atom and an ion conductive agent composed of one or more of a sulfonium salt, an ammonium salt, and a phosphonium salt, A conductive roll for an electrophotographic device, comprising a compound having an epoxy group and an ester group in a range from the outside of the outer peripheral surface of the shaft to the inside of the elastic layer.

2. 2. The conductive roll for an electrophotographic device according to claim 1, wherein the shaft and the elastic layer are bonded via an adhesive layer, and one or both of the elastic layer and the adhesive layer contains the compound having an epoxy group and an ester group.

3. 3. The conductive roll for electrophotographic equipment according to claim 1, wherein the polymer containing a halogen atom is a hydrin rubber.

4. 3. The conductive roll for electrophotographic equipment according to claim 2, wherein the adhesive layer contains the compound having an epoxy group and an ester group.

5. 3. The conductive roll for electrophotographic equipment according to claim 2, wherein the elastic layer contains the compound having an epoxy group and an ester group.

6. 5. The conductive roll for electrophotographic equipment according to claim 4, wherein the content of the compound having an epoxy group and an ester group is 0.004 parts by mass or more and 15 parts by mass or less relative to 100 parts by mass of the binder of the adhesive layer.

7. 6. The conductive roll for electrophotographic equipment according to claim 5, wherein the content of the compound having an epoxy group and an ester group is 0.004 parts by mass or more and 15 parts by mass or less relative to 100 parts by mass of the polymer containing a halogen atom in the elastic layer.

8. 3. The conductive roll for electrophotographic equipment according to claim 1, wherein the content of the ion conductive agent is 0.2 parts by mass or more and 6.5 parts by mass or less with respect to 100 parts by mass of the polymer containing a halogen atom.

9. 3. The conductive roll for electrophotographic equipment according to claim 1, wherein the compound having an epoxy group and an ester group has a weight average molecular weight Mw of 5,000 or more and 150,000 or less.

10. 3. The conductive roll for electrophotographic equipment according to claim 1, wherein the compound having an epoxy group and an ester group has an aromatic ring.

11. the shaft body and the elastic layer are bonded via an adhesive layer, the polymer containing a halogen atom is a hydrin rubber, the adhesive layer contains the compound having an epoxy group and an ester group, the content of the compound having an epoxy group and an ester group is 0.004 parts by mass or more and 15 parts by mass or less relative to 100 parts by mass of the binder of the adhesive layer, the content of the ion conductive agent is 0.2 parts by mass or more and 6.5 parts by mass or less with respect to 100 parts by mass of the polymer containing a halogen atom, the weight average molecular weight Mw of the compound having an epoxy group and an ester group is 5,000 or more and 150,000 or less; 2. The conductive roll for an electrophotographic apparatus according to claim 1, wherein the compound having an epoxy group and an ester group has an aromatic ring.

12. the shaft body and the elastic layer are bonded via an adhesive layer, the polymer containing a halogen atom is a hydrin rubber, the elastic layer contains the compound having an epoxy group and an ester group, the content of the compound having an epoxy group and an ester group is 0.004 parts by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the polymer containing a halogen atom of the elastic layer, the content of the ion conductive agent is 0.2 parts by mass or more and 6.5 parts by mass or less with respect to 100 parts by mass of the polymer containing a halogen atom, the weight average molecular weight Mw of the compound having an epoxy group and an ester group is 5,000 or more and 150,000 or less; 2. The conductive roll for an electrophotographic apparatus according to claim 1, wherein the compound having an epoxy group and an ester group has an aromatic ring.

13. 2. The conductive roll for an electrophotographic apparatus according to claim 1, wherein said shaft and said elastic layer are directly bonded to each other, and said elastic layer contains said compound having an epoxy group and an ester group.

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