Manufacturing method of conductive roller

Abstract

To provide a manufacturing method of a conductive roller capable of forming an incomplete membrane formed from resin on the surface of the conductive elastic layer of a conductive roller.SOLUTION: The manufacturing method of a conductive roller includes the following steps: an application step of applying resin powder to the outer peripheral surface of a conductive elastic layer of a roller member having a conductive shaft and the conductive elastic layer formed on the outer periphery of the conductive shaft; a diffusion step of diffusing resin powder over the entire outer peripheral surface of the conductive elastic layer using a diffusion member; and a heating step of heating the resin powder to fuse the resin powder to the outer peripheral surface of the conductive elastic layer to form an incomplete film.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a conductive roller.

Background Art

[0002] In an image forming apparatus using an electrophotographic method such as a laser printer, an electrostatic copier, a plain paper facsimile apparatus, or a multifunction machine thereof, for example, a conductive roller is used for a developing roller that exposes the surface of a charged photoreceptor and develops an electrostatic latent image formed on the surface into a toner image.

[0003] A developing roller having a role of carrying toner for image formation has a conductive elastic layer, and the surface of the conductive elastic layer is processed to have a predetermined shape and roughness for the stability of toner chargeability and conveyance amount. The surface shape of the conductive elastic layer can be controlled by polishing the surface of the elastic layer, but in the surface shape adjusted by such polishing, problems such as deterioration of printing density and toner adhesion to the surface of the elastic layer tend to occur due to wear of the surface of the elastic layer.

[0004] Therefore, as a method for controlling the surface shape of the conductive elastic layer, for example, Patent Document 1 proposes a method of forming a resin coating layer using a liquid paint in which coarse particles for appropriately imparting surface roughness are added to a urethane-based liquid paint and the viscosity is adjusted with an organic solvent or the like (see Patent Document 1 (paragraph 0132)).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] By forming a resin coating layer on the surface of the conductive elastic layer, the surface shape can be adjusted and the durability can be improved. However, in the method of forming a resin coating layer by applying and curing a liquid paint on the surface of the elastic layer of the conductive roller, VOC (volatile organic compound) is generated because the organic solvent volatilizes in the process of drying the liquid paint. Therefore, equipment for recovering the generated VOC is required. Also, there is electrostatic coating as a method of forming a resin coating layer. However, the resin coating layer formed by electrostatic coating is a complete film, and since the surface of the conductive elastic layer of the conductive roller is completely covered with resin, there is a problem that the electrical characteristics of the conductive roller deteriorate.

[0007] The present invention has been made in view of the above circumstances, and an object thereof is to provide a method for manufacturing a conductive roller capable of forming an incomplete film formed of resin on the surface of the conductive elastic layer of the conductive roller.

Means for Solving the Problems

[0008] The method for manufacturing a conductive roller of the present invention, which has solved the above problems, includes an applying step of applying resin powder to the outer peripheral surface of the conductive elastic layer of a roller member having a conductive shaft core and a conductive elastic layer formed on the outer periphery of the conductive shaft core, a diffusing step of diffusing the resin powder over the entire outer peripheral surface of the conductive elastic layer by a diffusing member, and a heating step of heating the resin powder to fuse the resin powder to the outer peripheral surface of the conductive elastic layer to form an incomplete film.

Effects of the Invention

[0009] According to the manufacturing method of the present invention, a conductive roller having an incomplete film formed of resin can be manufactured on the surface of the conductive elastic layer without using an organic solvent.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0011] [Conductive Roller] The method for manufacturing a conductive roller of the present invention is a method for manufacturing a conductive roller having a conductive shaft core, a conductive elastic layer formed on the outer periphery of the conductive shaft core, and a resin coating layer (an incomplete film formed from resin) formed on the surface of the conductive elastic layer. The surface properties of the conductive roller can be controlled by the resin coating layer, the durability of the resin coating layer is high, and since the resin coating layer is an incomplete film, the electrical characteristics of the conductive elastic layer are also good. Therefore, the conductive roller is useful as a developing roller for an image forming apparatus using the electrophotographic method.

[0012] Referring to FIGS. 1 and 2, an example of a conductive roller manufactured by the manufacturing method of the present invention will be described. FIG. 1 is a perspective view showing the overall appearance of an example of the conductive roller. FIG. 2 is a side view of the conductive roller of FIG. 1. The conductive roller 1 has a conductive shaft core 2 and a conductive elastic layer 3 provided on the outer peripheral surface of the conductive shaft core 2. The conductive shaft core 2 is inserted and fixed in the through hole 4 at the center of the conductive elastic layer. And a resin coating layer 5 is formed on the surface of the conductive elastic layer 3.

[0013] (Conductive Shaft Core) The conductive shaft core is not particularly limited as long as at least the surface has conductivity and it functions as a support for the conductive roller. The diameter of the conductive shaft core is not particularly limited, but is usually 4.0 mm to 12.0 mm. Examples of the conductive shaft core include a metal shaft core, and examples of the metal constituting the metal shaft core include aluminum, aluminum alloy, stainless steel, and the like.

[0014] (Conductive elastic layer) The conductive elastic layer is electrically joined and mechanically fixed to the conductive core through, for example, an adhesive having conductivity, or a conductive core having an outer diameter larger than the inner diameter of the through hole of the conductive elastic layer is press-fitted into the through hole, thereby being electrically joined and mechanically fixed to the conductive core. Alternatively, both of these methods may be used in combination to electrically join the conductive elastic layer to the conductive core and mechanically fix it.

[0015] The conductive elastic layer is formed from a rubber composition, is an elastic layer, and preferably has conductivity. Examples of the rubber composition include a rubber composition containing a base rubber, a conductive material, and a vulcanizing agent.

[0016] The type of the base rubber is not particularly limited, and rubbers conventionally used for conductive rollers can be used. Examples of the base rubber include epichlorohydrin rubber, diene rubber, ethylene-α-olefin-diene copolymer, etc. These base rubbers may be used alone or in combination of two or more.

[0017] As the epichlorohydrin rubber, various polymers containing epichlorohydrin as a repeating unit can be used. Examples of the epichlorohydrin rubber include epichlorohydrin homopolymer (CO), epichlorohydrin-ethylene oxide binary copolymer (ECO), epichlorohydrin-propylene oxide binary copolymer, epichlorohydrin-allyl glycidyl ether binary copolymer, epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer (GECO), epichlorohydrin-propylene oxide-allyl glycidyl ether terpolymer, and epichlorohydrin-ethylene oxide-propylene oxide-allyl glycidyl ether quaternary copolymer, etc., one or more of which are included. Among the above examples, copolymers containing ethylene oxide, particularly ECO and / or GECO, are preferred as the epichlorohydrin rubber.

[0018] The diene rubber imparts good processability to the rubber composition and improves the mechanical strength and durability of the base layer. Examples of the diene rubber include natural rubber, isoprene rubber (IR), chloroprene rubber (CR), acrylonitrile-butadiene rubber (NBR), styrene-butadiene rubber (SBR), and butadiene rubber (BR). Among these, isoprene rubber, chloroprene rubber, and acrylonitrile-butadiene rubber are preferred as the diene rubber.

[0019] The chloroprene rubber is synthesized by emulsion polymerization of chloroprene and is classified into a sulfur-modified type and a non-sulfur-modified type depending on the type of molecular weight regulator used. The non-sulfur-modified type is further classified into a mercaptan-modified type, a xanthogen-modified type, etc. Also, a copolymer of chloroprene and other copolymerization components may be used as the chloroprene rubber. Examples of the other copolymerization components include one or more of 2,3-dichloro-1,3-butadiene, 1-chloro-1,3-butadiene, styrene, acrylonitrile, methacrylonitrile, isoprene, butadiene, acrylic acid, acrylic acid ester, methacrylic acid, and methacrylic acid ester.

[0020] As the chloroprene rubber, there are an oil-extended type with extender oil added to adjust flexibility and a non-oil-extended type without added extender oil. In the present invention, in order to prevent contamination of the photoreceptor, it is preferable to use a non-oil-extended type that does not contain extender oil that can be a bleeding substance.

[0021] As the acrylonitrile-butadiene rubber, various acrylonitrile-butadiene rubbers synthesized by copolymerizing acrylonitrile and butadiene by various polymerization methods such as emulsion polymerization method and having crosslinkability can all be used. As the acrylonitrile-butadiene rubber, low-nitrile NBR with an acrylonitrile content of 24% by mass or less, medium-nitrile NBR with an acrylonitrile content of 25% to 30% by mass, medium-high-nitrile NBR with an acrylonitrile content of 31% to 35% by mass, high-nitrile NBR with an acrylonitrile content of 36% to 42% by mass, and extremely high-nitrile NBR with an acrylonitrile content of 43% by mass or more can all be used.

[0022] As the acrylonitrile-butadiene rubber, there are an oil-extended type in which extender oil is added to adjust flexibility and a non-oil-extended type in which extender oil is not added, and the non-oil-extended type is preferred.

[0023] The ethylene-α-olefin-diene copolymer is a copolymer in which a small amount of a diene component is added to ethylene and an α-olefin to introduce a double bond into the main chain. Examples of the α-olefin include propylene, 1-butene, 1-hexene, 1-octene, and the like. Examples of the diene component include ethylidene norbornene (ENB), 1,4-hexadiene (1,4-HD), dicyclopentadiene (DCP), and the like, and ethylidene norbornene is preferred. Examples of the ethylene-α-olefin-diene copolymer include ethylene-propylene-diene copolymer (EPDM), ethylene-butene-diene copolymer (EBDM), ethylene-propylene-butene-diene copolymer (EPBDM), and the like.

[0024] The ethylene-α-olefin-diene copolymer has an oil-extended type in which extender oil is added to adjust flexibility and a non-oil-extended type in which extender oil is not added, and the non-oil-extended type is preferred.

[0025] Examples of the conductive material include ion conductive agents, carbon black, and the like. The conductive material may be used alone or in combination of two or more.

[0026] Examples of the ion conductive agent include quaternary ammonium salts, metal salts of carboxylic acids, carboxylic acid derivatives such as carboxylic acid anhydrides or esters, condensates of aromatic compounds, organometallic complexes, metal salts, chelate compounds, monoazo metal complexes, acetylacetone metal complexes, hydroxycarboxylic acid metal complexes, polycarboxylic acid metal complexes, polyol metal complexes, and the like. The ion conductive agent may be used alone or in combination of two or more kinds.

[0027] Particularly preferred examples of the ion conductive agent include LiOSO2CF3, LiOSO2C3F7, LiOSO2C4F9, LiN(CF3SO2)2, LiN(C4F9SO2)2, LiC(CF3SO2)3, LiCH(CF3SO2)2, KOSO2CF3, KOSO2C3F7, KOSO2C4F9, KN(CF3SO2)2, KN(C4F9SO2)2, KC(CF3SO2)3, and KCH(CF3SO2)2.

[0028] The type of the carbon black is not particularly limited. Examples of the carbon black include furnace carbon blacks such as SAF (Super Abrasion Furnace Black), ISAF (Intermediate Super Abrasion Furnace Black), IISAF (Intermediate ISAF), HAF (High Abrasion Furnace Black), MAF (Medium Abrasion Furnace Black), FEF (Fast Extruding Furnace Black), SRF (Semi-Reinforcing Furnace Black), GPF (General Purpose Furnace Black), FF (Fine Furnace Black), CF (Conductive Furnace Black); thermal carbon blacks such as FT (Fine Thermal Black), MT (Medium Thermal Black); channel carbon blacks such as EPC (Easy Processing Channel Black), MPC (Medium Processing Channel Black); and acetylene black. The carbon black may be used alone or in combination of two or more.

[0029] Examples of the vulcanizing agent include one or more of, for example, sulfur-based vulcanizing agents, thiourea-based vulcanizing agents, triazine derivative-based vulcanizing agents, peroxide vulcanizing agents, various monomers, etc. As the vulcanizing agent, a sulfur-based vulcanizing agent is preferred.

[0030] Examples of the sulfur-based vulcanizing agent include elemental sulfur and sulfur donor type compounds. Examples of the elemental sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, and insoluble sulfur. Examples of the sulfur donor type compound include 4,4'-dithiomorpholine. The sulfur-based vulcanizing agent may be used alone or in combination of two or more.

[0031] The rubber composition may contain compounding agents such as vulcanization accelerators, vulcanization aids, acid acceptors, fillers, antioxidants, processing aids, lubricants, and dispersants, as necessary. It is preferable to appropriately select those compounding agents that are less likely to cause blooming or bleeding.

[0032] The rubber composition may contain a vulcanization accelerator. As the vulcanization accelerator, either an inorganic accelerator or an organic accelerator can be used. Examples of the inorganic accelerator include slaked lime, magnesia (MgO), litharge (PbO), etc. Examples of the organic accelerator include, for example, thiuram accelerators, thiourea accelerators, thiazole accelerators, guanidine accelerators, sulfenamide accelerators, dithiocarbamate accelerators, etc. The crosslinking accelerator may be used alone or in combination of two or more kinds.

[0033] Examples of the thiuram accelerator include tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, tetrakis(2-ethylhexyl)thiuram disulfide, dipentamethylenethiuram tetrasulfide, etc., and tetramethylthiuram monosulfide is preferable.

[0034] Examples of the thiazole accelerator include 2-mercaptobenzothiazole, di-2-benzothiazolyldisulfide, zinc salt of 2-mercaptobenzothiazole, cyclohexylamine salt of 2-mercaptobenzothiazole, 2-(N,N-diethylthiocarbamoylthio)benzothiazole, 2-(4'-morpholinodithio)benzothiazole, etc., and di-2-benzothiazolyldisulfide is preferable.

[0035] Examples of the thiourea accelerator include ethylene thiourea, trimethylthiourea, N,N'-diethylthiourea, tributylthiourea, dibutylthiourea, dilaurylthiourea, N,N'-diphenylthiourea, etc. Among these, ethylene thiourea is preferable.

[0036] Examples of the guanidine-based accelerator include 1,3-diphenylguanidine, 1,3-di-o-tolylguanidine, and the like.

[0037] Examples of the vulcanization aid include one or more of conventionally known vulcanization aids such as metal compounds such as zinc oxide (zinc white); fatty acids such as stearic acid, oleic acid, and cottonseed oil.

[0038] The acid acceptor prevents chlorine-based gas generated from CR or the like during vulcanization of the rubber component from remaining in the conductive roller, thereby causing vulcanization inhibition or contamination of members (for example, a photoreceptor drum) in contact with the conductive roller. As the acid acceptor, various substances that act as acid receptors can be used, but hydrotalcites or magsaratts having excellent dispersibility are preferable, and hydrotalcites are particularly preferable.

[0039] Examples of the anti-aging agent include 4,4'-dicumyldiphenylamine, nickel diethyldithiocarbamate, nickel dibutyldithiocarbamate, and the like.

[0040] The rubber composition can be prepared by blending each raw material and kneading it with a pressure kneader, a Banbury mixer, an open roll, or the like. The kneading method and conditions are appropriately selected according to the production scale.

[0041] The conductive elastic layer may have a single-layer structure or a multilayer structure of two or more layers. When the conductive elastic layer has a multilayer structure, each layer may be formed from the same rubber composition or may be formed from rubber compositions having different compositions.

[0042] The thickness of the conductive elastic layer is preferably 1 mm or more, more preferably 2 mm or more, preferably 10 mm or less, and more preferably 5 mm or less.

[0043] The surface of the conductive elastic layer may be surface-modified by dry processes such as electron beam, ultraviolet ray, and corona discharge. It is preferable that the surface of the conductive elastic layer is irradiated with ultraviolet rays. Further, it is preferable that an oxide film is formed on the outer peripheral surface of the conductive elastic layer. The oxide film is a film formed by oxidizing the base rubber. The oxide film can be formed by irradiating the surface of the conductive elastic layer with ultraviolet rays in the presence of oxygen.

[0044] (Resin coating layer) The resin coating layer is an incomplete film formed of resin. An incomplete film is a film having a plurality of through-holes penetrating in the thickness direction. That is, on the surface of the conductive elastic layer, there are portions covered with the resin coating layer and portions where the conductive elastic layer is exposed. By having such a resin coating layer, when used as a developing roller, toner adhesion to a blade disposed in the vicinity of the developing roller can be suppressed, and the occurrence of image defects can be prevented. Note that the planar shape of the through-holes of the incomplete film is not particularly limited, but the maximum diameter of each is 50 μm or less. The maximum diameter of the through-holes may be measured by observing the resin coating layer with a microscope.

[0045] The resin is not particularly limited as long as it is a thermoplastic resin. Examples of the resin include polyolefin resins (such as polyethylene resin and polypropylene resin), polyester resins (such as polyethylene terephthalate resin and polybutylene terephthalate resin), polyamide resins (nylon 6, nylon 66, copolymerized nylon), polyurethane resins, polyacrylic resins, and ethylene-acrylic copolymer resins.

[0046] In the incomplete film, the ratio of the portion other than the through-holes in the area of the incomplete film is preferably 25% or more, more preferably 26% or more, preferably 45% or less, and more preferably 40% or less. When the ratio is within the above range, the generation of white streaks is suppressed when forming a solid black image.

[0047] The thickness of the resin coating layer is preferably 2 μm or more, more preferably 3 μm or more, still more preferably 5 μm or more, and preferably 20 μm or less, more preferably 15 μm or less, still more preferably 10 μm or less. If the thickness of the resin coating layer is 2 μm or more, the effect of the resin coating layer becomes greater, and the occurrence of image defects can be more suppressed. If it is 20 μm or less, the influence of the resin coating layer on the surface resistance value of the conductive elastic layer is more suppressed, and the performance when used as a developing roller is further improved.

[0048] The basis weight of the resin coating layer is preferably 0.5 mg / cm 2 or more, more preferably 1.0 mg / cm 2 or more, still more preferably 1.5 mg / cm 2 or more, and preferably 4.0 mg / cm 2 or less, more preferably 3.5 mg / cm 2 or less, still more preferably 3.0 mg / cm 2 or less. If the basis weight is 0.5 mg / cm 2 or more, the effect of the resin coating layer becomes greater, and the occurrence of image defects can be more suppressed. If it is 4.0 mg / cm 2 or less, the influence of the resin coating layer on the surface resistance value of the conductive elastic layer is more suppressed, and the performance when used as a developing roller is further improved.

[0049] [Manufacturing method of conductive roller] The manufacturing method of the conductive roller of the present invention includes an application step of applying resin powder to the outer peripheral surface of a roller member having a conductive shaft core and a conductive elastic layer formed on the outer periphery of the conductive shaft core, a diffusion step of diffusing the resin powder over the entire outer peripheral surface of the conductive elastic layer by a diffusion member, and a heating step of heating the resin powder to fuse the resin powder to the outer peripheral surface of the conductive elastic layer to form an incomplete film. As described above, since the conductive roller is useful as a developing roller, the manufacturing method of the conductive roller of the present invention is useful as a manufacturing method of a developing roller.

[0050] (Preparation of roller member) The roller member is not particularly limited as long as it has a conductive shaft core and a conductive elastic layer formed on the outer periphery of the conductive shaft core.

[0051] Hereinafter, an example of a method for producing a conductive elastic layer will be described. To form the conductive elastic layer, first, the prepared rubber composition is extruded into a cylindrical shape using an extruder, cut to a predetermined length, and then pressurized and heated in a vulcanizing can to crosslink the rubber. Next, the crosslinked cylindrical body is heated using an oven or the like for secondary crosslinking and then cooled to form a cylindrical member which is a precursor of the conductive elastic layer. Here, the outer peripheral surface may be polished so as to have a predetermined outer diameter. As the polishing method, various polishing methods such as dry traverse polishing can be adopted.

[0052] The conductive shaft core can be inserted and fixed into the through hole of the cylindrical member at any time from after cutting the cylindrical member to after polishing. However, it is preferable to first insert the conductive shaft core into the through hole and then perform secondary crosslinking and polishing. Thereby, warping and deformation of the conductive elastic layer due to expansion and contraction during secondary crosslinking can be suppressed. Also, by polishing while rotating around the conductive shaft core, the workability of the polishing can be improved, and warping of the outer peripheral surface can be suppressed.

[0053] For the conductive shaft core, one having an outer diameter larger than the inner diameter of the through hole of the cylindrical member may be press-fitted into the through hole, or inserted into the through hole of the cylindrical member before secondary crosslinking through a thermosetting adhesive having conductivity. In the former case, electrical bonding and mechanical fixing with the conductive elastic layer are completed simultaneously with the press-fitting of the conductive shaft core. In the latter case, when the cylindrical member is secondarily crosslinked by heating in an oven, the thermosetting adhesive is cured at the same time, so that the conductive shaft core is electrically bonded to the conductive elastic layer and mechanically fixed. Also, as described above, both of these may be used in combination to electrically bond and mechanically fix the conductive shaft core to the conductive elastic layer.

[0054] (UV irradiation process) In the method for manufacturing the conductive roller of the present invention, an ultraviolet irradiation step of irradiating the surface of the conductive elastic layer with ultraviolet rays may be included before the application step described later. By irradiating ultraviolet rays, the friction coefficient of the conductive elastic layer can be reduced, the tackiness can be reduced, and slipperiness can be imparted.

[0055] When performing an ultraviolet irradiation treatment on the surface of the conductive elastic layer, it is preferable to use a low-pressure mercury lamp. Since the low-pressure mercury lamp mainly emits ultraviolet rays with wavelengths of 185 nm and 254 nm, the surface modification of the conductive elastic layer can be efficiently performed. Also, when using a low-pressure mercury lamp, the ultraviolet irradiation dose is 100 mJ / cm 2 ~5000 mJ / cm 2 and it is preferably set to this range.

[0056] (Application step) In the application step, resin powder is applied to the outer peripheral surface of the conductive elastic layer of a roller member having a conductive shaft core and a conductive elastic layer formed on the outer periphery of the conductive shaft core.

[0057] The resin powder is not particularly limited as long as it is a powder of a thermoplastic resin. Examples of the resin powder include polyolefin resin powders (such as polyethylene resin powder and polypropylene resin powder), polyester resin powders (such as polyethylene terephthalate resin powder and polybutylene terephthalate resin powder), polyamide resin powders (such as nylon 6 powder, nylon 66 powder, and copolymerized nylon powder), polyurethane resin powder, polyacrylic resin powder, ethylene-acrylic copolymer resin powder, and the like. Among these, polyolefin resin powder is preferable, and high-density polyethylene resin powder is more preferable. The density of the high-density polyethylene resin is 0.94 g / cm 3 or more at 23°C. The density is measured according to JIS K7112.

[0058] The melting point (JIS K7121) of the resin powder is preferably 100°C or higher, more preferably 110°C or higher, still more preferably 120°C or higher, and preferably 160°C or lower, more preferably 150°C or lower, still more preferably 140°C or lower.

[0059] The volume median diameter (particle diameter corresponding to 50% cumulative in the volume cumulative distribution with the smaller diameter side being 0) of the resin powder by the Coulter method is preferably 30 μm or less, more preferably 20 μm or less, and even more preferably 15 μm or less. If the volume median diameter is 30 μm or less, it becomes easier to uniformly apply the resin powder to the surface of the conductive elastic layer. The lower limit of the volume median diameter is not particularly limited, but is preferably 1 μm or more. If the volume median diameter is 1 μm or more, the workability when applying the resin powder is improved.

[0060] The amount of the resin powder applied to the surface of the conductive elastic layer may be appropriately adjusted according to the surface condition of the conductive elastic layer and the powder property of the resin powder to be applied. As the amount of the resin powder applied, per 1 cm 2 of the surface area of the conductive elastic layer, 1.0 mg or more is preferable, more preferably 1.5 mg or more, and even more preferably 2.0 mg or more, and 20 mg or less is preferable, more preferably 10 mg or less, and even more preferably 5.0 mg or less.

[0061] The method for applying the resin powder to the outer peripheral surface of the conductive elastic layer is not particularly limited, and examples include a method of applying by directly spraying the resin powder on the surface of the conductive elastic layer, and a method of applying by transferring the resin powder sprayed on a transfer body to the surface of the conductive elastic layer. Examples of the method of applying by directly spraying the resin powder on the surface of the conductive elastic layer include a method of brushing the resin powder on the surface of the conductive elastic layer using a brush; a method of spraying the resin powder from above the conductive elastic layer, etc.

[0062] As a method of applying the resin powder scattered on the transfer body to the surface of the conductive elastic layer by transferring it, there is a method of applying the resin powder to the outer peripheral surface of the conductive elastic layer by pressing the conductive elastic layer against the transfer body holding the resin powder. Specifically, there are a method of dispersing the resin powder on a flat plate (transfer plate), rolling the conductive elastic layer on the flat plate holding the resin powder, and transferring the resin powder to the surface of the conductive elastic layer; a method of dispersing the resin powder on the surface of a transfer roll, pressing the conductive elastic layer against the transfer roll holding the resin powder, and rotating it to transfer the resin powder to the surface of the conductive elastic layer, etc. By using a transfer body, the amount and uniformity of the resin powder applied to the conductive elastic layer can be easily controlled by adjusting the amount and uniformity of the resin powder scattered on the transfer body.

[0063] Referring to FIGS. 3 and 4, an example of a method of applying the resin powder scattered on the transfer body to the surface of the conductive elastic layer by transferring it will be described. FIG. 3 is a schematic diagram showing an example of a method of applying the resin powder to the outer peripheral surface of the conductive elastic layer using a transfer plate. FIG. 4 is a schematic diagram showing an example of a method of applying the resin powder to the outer peripheral surface of the conductive elastic layer using a transfer roller.

[0064] In the method shown in FIG. 3, the resin powder 10 is dispersed on the transfer plate 11, and the conductive roller 1 is rolled on the transfer plate 11 holding the resin powder 10, and the resin powder 10 is transferred to the surface of the conductive elastic layer 3. The resin powder 10 is leveled by the regulating plate 12 and uniformly dispersed on the transfer plate 11. By rotating and rolling the conductive roller 1 in the direction of arrow X on the transfer plate 11, the conductive elastic layer 3 is pressed against the transfer plate 11 by the self-weight of the conductive roller 1. Then, at the nip portion of the conductive elastic layer 3, the resin powder 10 is transferred from the transfer plate 11 to the conductive elastic layer 3, and the resin powder 10 is applied to the surface of the conductive elastic layer 3. Note that the conductive roller 1 may be biased in the direction of the transfer plate 11 to increase the pressing force on the transfer plate 11.

[0065] The material of the transfer plate 11 is not particularly limited as long as it can hold the resin powder 10 on the transfer plate 11 and can transfer the resin powder 10 onto the surface of the conductive elastic layer 3. Examples of the material of the transfer plate 11 include metals such as stainless steel, resins, ceramics, and the like. The surface of the transfer plate 11 is preferably flat. Therefore, for example, when the material of the transfer plate 11 is stainless steel, the arithmetic mean surface roughness (Ra) of its surface is preferably 1.0 μm to 1.5 μm.

[0066] The material of the restricting plate 12 is not particularly limited as long as it can uniformly disperse the resin powder 10 on the transfer plate 11. Also, regarding the arrangement position of the restricting plate 12, it may be appropriately adjusted according to the amount of the resin powder 10 finally transferred onto the surface of the conductive elastic layer 3.

[0067] In the method shown in FIG. 4, the resin powder 10 is dispersed on the surface of the transfer roller 13, and the transfer roller 13 holding the resin powder 10 is rotated while being pressed against the conductive roller 1, so that the resin powder 10 is transferred onto the surface of the conductive elastic layer 3. The resin powder 10 is leveled by the restricting blade 14 and uniformly dispersed on the surface of the transfer roller 13. The conductive roller 1 is pressed against the transfer roller 13. As the conductive roller 1 rotates in the direction of arrow Y and the transfer roller 13 rotates in the direction of arrow Z, at the nip portion of the conductive elastic layer 3, the resin powder 10 is transferred from the transfer roller 13 to the conductive elastic layer 3, and the resin powder 10 is applied to the surface of the conductive elastic layer 3.

[0068] The material of the transfer roller 13 is not particularly limited as long as it can hold the resin powder 10 on the transfer roller 13 and can transfer the resin powder 10 onto the surface of the conductive elastic layer 3. Examples of the material of the transfer roller 13 include metals such as stainless steel, resins, ceramics, and the like. The surface of the transfer roller 13 is preferably flat. Therefore, for example, when the material of the transfer roller 13 is stainless steel, the arithmetic mean surface roughness (Ra) of its surface is preferably 1.0 μm to 1.5 μm.

[0069] The material of the regulating blade 14 is not particularly limited as long as it can uniformly disperse the resin powder 10 on the surface of the transfer roller 13. Also, regarding the arrangement position of the regulating blade 14, it may be appropriately adjusted according to the amount of the resin powder 10 finally transferred to the surface of the conductive elastic layer 3.

[0070] (Diffusion process) In the diffusion process, the resin powder is diffused over the entire outer peripheral surface of the conductive elastic layer by a diffusion member.

[0071] The diffusion member is not particularly limited as long as it can diffuse the resin powder. Examples of the diffusion member include elastic members such as foamed rubber, solid rubber, and foamed resin, fabrics, brushes, etc. Elastic members are preferred, and foamed rubber is particularly preferred. An elastic member is a member that can be deformed by an external force and returns to almost its original shape when the external force is removed. The Asker-C hardness of the elastic member is preferably 40 or less, more preferably 35 or less. The lower limit of the Asker-C hardness of the elastic member is not particularly limited, but 10 is preferred.

[0072] The shape of the diffusion member is not particularly limited, and examples include a cylindrical shape or a non-cylindrical shape. When the diffusion member is an elastic member, the cylindrical shape includes a sheet-like member rolled into a cylindrical shape.

[0073] When the diffusion member is an elastic member, its shape is preferably a cylindrical shape through which the roller member can be inserted. The elastic member is deformable and can contract its inner diameter. Therefore, if the elastic member is cylindrical, by inserting the roller member into the through-hole of the cylinder and adjusting the inner diameter of the elastic member so as to contact the entire circumference around the axis of the roller member, the resin powder can be easily diffused over the entire circumference around the axis of the roller member. The dimensions of the cylindrical elastic member are not particularly limited, but the thickness is preferably 3 mm to 20 mm, and the width is preferably 10 mm to 100 mm.

[0074] As a method of diffusing the resin powder by the diffusion member, there is a method of sliding the diffusion member in a state of being in contact with the conductive elastic layer. When sliding the diffusion member, the diffusion member may be slid in the axial direction of the roller member, the direction around the axis of the roller member, or both of these directions. When sliding the diffusion member in a state of being in contact with the conductive elastic layer, the roller member may be fixed and the diffusion member may be slid, the diffusion member may be fixed and the roller member may be slid, or both the roller member and the diffusion member may be slid relative to each other.

[0075] In particular, it is preferable to diffuse the resin powder by sliding the diffusion member in the axial direction of the roller member on the outer peripheral surface of the conductive elastic layer while rotating the roller member around its axis. By adopting such a diffusion method, the resin powder can be diffused in the axial direction and the direction around the axis of the roller member, and the resin powder can be diffused more uniformly.

[0076] Also, when sliding the diffusion member, it is preferable to slide the diffusion member in a state of being pressed against the outer peripheral surface of the conductive elastic layer to diffuse the resin powder. By sliding the diffusion member in a pressed state, it can be diffused more uniformly and the desired coating amount can be achieved.

[0077] When sliding the diffusion member in a pressed state, the pressure for pressing the diffusion member against the conductive elastic layer is preferably 0.01 MPa or more, more preferably 0.03 MPa or more, preferably 0.1 MPa or less, and more preferably 0.06 MPa or less.

[0078] The method of pressing the diffusion member against the conductive elastic layer is not particularly limited, and any method that can press with a constant pressure may be used. If the diffusion member is cylindrical, after inserting the roller member through the through-hole of the cylinder, the diffusion member can be pressed against the conductive elastic layer by contracting the inner diameter of the cylinder. If the diffusion member is non-cylindrical, the diffusion member may be pressed against the conductive elastic layer using a biasing means.

[0079] When a cylindrical elastic member is used as the diffusion member, for example, a tube body capable of expanding and contracting is arranged around the elastic member, a cylindrical member formed of a rigid material is arranged around this tube body, after inserting the roller member through the through-hole of the cylinder, by filling the tube material with compressed air and expanding it, a method of contracting the inner diameter of the elastic member and pressing the elastic member against the conductive elastic layer can be mentioned. In this method, by forming the inner diameter of the cylindrical elastic member larger than the outer diameter of the roller member, it becomes easy to insert the roller member through the through-hole of the cylinder, and also, after diffusing the resin powder, if the tube body is contracted, it becomes easy to pull out the roller member from the through-hole of the elastic member.

[0080] The application amount (after diffusion) of the resin powder applied to the surface of the conductive elastic layer is preferably 0.5 mg or more, more preferably 1.0 mg or more, still more preferably 1.5 mg or more per 1 cm 2 of the surface area of the conductive elastic layer, and preferably 4.0 mg or less, more preferably 3.5 mg or less, still more preferably 3.0 mg or less. If the application amount is 0.5 mg or more per 1 cm 2 of the surface area of the conductive elastic layer, the effect of the resin coating layer becomes greater, and the occurrence of image defects can be more suppressed when used as a developing roller. If it is 4.0 mg or less, the influence on the surface resistance value of the conductive elastic layer by the resin coating layer is more suppressed, and the performance when used as a developing roller is more improved.

[0081] (Heating process) In the heating process, by heating the resin powder, the resin powder is fused to the outer peripheral surface of the conductive elastic layer to form an incomplete film.

[0082] The method of heating the resin powder is not particularly limited, and examples include a method of heating the roller member to which the resin powder is applied in an oven.

[0083] When heating the resin powder, the heat treatment temperature (ambient temperature) is preferably such that the difference (T1 - T2), where T1 is the heat treatment temperature and T2 is the melting point of the resin powder, is 0 °C or more, more preferably 5 °C or more, still more preferably 10 °C or more. If the difference (T1 - T2) is 0 °C or more, the outermost layer can be formed. The upper limit of the difference (T1 - T2) is not particularly limited, but is preferably 50 °C or less, more preferably 40 °C or less. If the difference (T1 - T2) is 50 °C or less, the adverse effect on the elastic layer due to heat treatment can be suppressed.

[0084] The heat treatment time when fusing the resin powder is not particularly limited and may be appropriately adjusted according to the melting point of the resin and the heat treatment temperature.

[0085] A conductive roller with an incomplete film formed by the heating step is obtained. The surface roughness (the surface roughness of the conductive elastic layer on which the incomplete film is formed) (arithmetic mean roughness, ISO25178) Sa of the conductive roller is preferably 0.7 μm or more, more preferably 0.8 μm or more, still more preferably 0.9 μm or more, particularly preferably 1.0 μm or more, and preferably 1.5 μm or less, more preferably 1.4 μm or less, still more preferably 1.3 μm or less.

Examples

[0086] Hereinafter, the present invention will be described in detail by way of examples. However, the present invention is not limited by the following examples, and any modifications and embodiments within the scope not departing from the gist of the present invention are all included in the scope of the present invention.

[0087] [Evaluation Method] (1) Asker-C hardness The Asker-C hardness of the diffusion member was measured on the outer surface of the foamed rubber having a cylindrical shape as the diffusion member (inner diameter 13.1 mm, thickness 10 mm) with a temporary iron core (outer diameter 16 mm) inserted through the through hole. The measurement was carried out in an environment of temperature 23 °C and relative humidity 55%, and the value 3 seconds after inserting the indentation needle into the measurement sample was recorded.

[0088] (2) Surface resistance value of the conductive elastic layer The surface resistance value R (Ω, when 100 V is applied) of the conductive elastic layer was measured in surface resistance mode using a resistivity meter (manufactured by Mitsubishi Chemical Analytech Co., Ltd., Hi-Rester (registered trademark) UP MCP-HT450) and an MCP probe (UA type) (manufactured by Mitsubishi Chemical Analytech Co., Ltd.). Specifically, an MCP probe was applied with a load of 480 g against the axial center of the outer peripheral surface of the elastic layer, and the value after 10 seconds was taken as the surface resistance value R (Ω, when 100 V is applied) of the elastic layer. The measurement was performed for the surface resistance value (R1) of the conductive elastic layer before the formation of the resin coating layer and the surface resistance value (R2) of the conductive elastic layer after the formation of the resin coating layer, and the difference between these (logR2 - logR1) was obtained.

[0089] (3) Ratio of the portion other than the through holes The conductive elastic layer was photographed using a microscope (manufactured by Keyence Corporation, model "VHX-7100", effective magnification 1000 times). For the obtained image, it was binarized into a resin portion and a through hole portion (the portion where the base layer was exposed) using the built-in software, and the ratio of the area of the resin portion to the total area was calculated.

[0090] (4) Surface roughness The surface roughness (arithmetic mean roughness, ISO25178) Ra of the conductive elastic layer, transfer roller, and transfer plate on which the resin coating layer was formed was measured using a laser microscope (manufactured by Keyence Corporation, "VK-X3000").

[0091] (5) Printing test The conductive roller was used for the developing roller of a toner cartridge (manufactured by Brother, "TN-29J") for a laser printer (manufactured by Brother, "HL-L2370DN"), and a printing test was performed. In the test, immediately after continuously forming 30 images with a 1% concentration on A4-sized paper (TANOSEE PPC paper, SNOW WHITE, sold by Otsuka Shokai) under low temperature and low humidity conditions of 10 ± 1°C and relative humidity of 20 ± 1%, a solid black image with a size of 3 cm square was formed. Then, the image density was measured at any 5 points on the formed solid black image using a reflection densitometer (manufactured by Konica Minolta, "FD-5"), and the average value was obtained. When the average value of the image density was 1.3 or more, it was evaluated as "〇"; when the average value of the image density was 1.2 or more and less than 1.3, it was evaluated as "△"; when the average value of the image density was less than 1.2, it was evaluated as "×". Also, the solid black image was visually observed, and when there was no unevenness, it was evaluated as "◎"; when a slight unevenness was felt, it was evaluated as "〇"; when the unevenness could be clearly confirmed, it was evaluated as "×".

[0092] [Manufacturing Method of Conductive Roller] Conductive Roller No.1 (Preparation of Roller Member) The compounding materials shown in Table 1 were kneaded with a Banbury mixer and then extruded into a tube (outer diameter 14 mm, inner diameter 6.5 mm) using an extruder. This tube was attached to a shaft for vulcanization, vulcanized at 160°C for 1 hour in a vulcanizing kettle, and then attached to a mandrel (outer diameter 6.0 mm) coated with a conductive adhesive and adhered in an oven at 160°C. After that, the end of the tube adhered to the shaft was shaped, traversed and polished with a cylindrical grinding machine, and then mirror-polished as the final finishing polish to form a conductive elastic layer (outer diameter 13.0 mm, width 234 mm). The mirror polishing was performed with a lapping film #600 (manufactured by Sankyo Rikagaku, mirror film).

[0093] (UV Irradiation Process) After wiping the outer peripheral surface of the polished base layer with alcohol, it was set in a UV treatment device, and the conductive elastic layer was surface-treated by UV irradiation.

[0094]

Table 1

[0095] (Application process) For the roller member after ultraviolet irradiation, resin powder (high-density polyethylene (HDPE): Flow Beads (Registered Trademark) HE-3040 (manufactured by Sumitomo Seika); volume median diameter (Coulter method) 11 μm, melting point (JIS K7121) 130 °C, density (JIS K7112) 0.96 g / cm 3 ) was applied in a small amount (0.1 g or less in mass, 3 mg per 1 cm of the surface area of the conductive elastic layer) to the outer peripheral surface of the conductive elastic layer with a brush. 2

[0096] (Diffusion process) ​The resin powder applied to the outer surface of the conductive elastic layer was diffused over the entire outer peripheral surface of the conductive elastic layer by a diffusion member. As the diffusion member, a foamed rubber having a cylindrical shape through which a roller member can be inserted (inner diameter 13.1 mm, thickness 10 mm, width 50 mm) was used. The foamed rubber has elasticity, and the inner diameter of the cylinder can be increased or decreased. The foamed rubber was attached to a jig having an expandable rubber tube body disposed around the circumference of the cylinder of the foamed rubber and a cylindrical member formed of a rigid material disposed around the tube body. After inserting the roller member through the through-hole of the foamed rubber, the roller member was rotatably supported, and the jig was disposed slidably in the axial direction of the roller member. Then, by filling the tube body of the jig with compressed air and expanding it, the foamed rubber was pressed against the conductive elastic layer, and while rotating the roller member around the axis, the jig was reciprocated a plurality of times in the roller axis direction to diffuse the resin powder. The mass of the roller member before and after diffusing the resin powder was measured, and the amount of the resin powder applied was measured.

[0097] (Heating process) After diffusing the resin powder, the roller member was heated in an oven at 160 °C for 20 minutes to fuse the resin powder to the conductive elastic layer, obtaining Conductive Roller No. 1.

[0098] Conductive Roller No. 2 In the diffusion process, Conductive Roller No. 2 was obtained in the same manner as the manufacturing method of Conductive Roller No. 1, except that the jig was reciprocated a plurality of times in the roller axis direction without rotating the roller member around the axis to diffuse the resin powder.

[0099] Conductive Roller No. 3 In the diffusion process, Conductive Roller No. 3 was obtained in the same manner as the manufacturing method of Conductive Roller No. 1, except that a foamed rubber having a cylindrical shape through which a roller member can be inserted (inner diameter 14.0 mm) was used as the diffusion member and the compressed air filled in the tube body of the jig was adjusted to increase the pressing force.

[0100] Conductive Roller No. 4 In the diffusion process, the conductive roller No. 4 was obtained in the same manner as the manufacturing method of the conductive roller No. 1, except that the jig was reciprocated a plurality of times in the roller axis direction without rotating the roller member to diffuse the resin powder.

[0101] Conductive roller No. 5 A roller member was produced in the same manner as the manufacturing method of the conductive roller No. 1. For this roller member, resin powder (high-density polyethylene (HDPE): Flow Beads (registered trademark) HE-3040 (manufactured by Sumitomo Seika)) was applied to the outer peripheral surface of the conductive elastic layer by electrostatic coating. The application amount of the resin powder was 0.2 g (20 mg per 1 cm of the surface area of the conductive elastic layer). 2 per 1 cm of the surface area of the conductive elastic layer). After applying the resin powder, the roller member was heated in an oven at 160 °C for 20 minutes to fuse the resin powder to the conductive elastic layer, and the conductive roller No. 5 was obtained.

[0102] Conductive roller No. 6 The conductive roller No. 6 was obtained in the same manner as the manufacturing method of the conductive roller No. 5, except that the application amount of the resin powder by electrostatic coating was changed to 0.3 g (30 mg per 1 cm of the surface area of the conductive elastic layer). 2 per 1 cm of the surface area of the conductive elastic layer).

[0103] Conductive roller No. 7 (Preparation of roller member, ultraviolet irradiation process) A roller member was manufactured in the same manner as the manufacturing method of the conductive roller No. 1, and the surface of the conductive elastic layer was treated by ultraviolet irradiation.

[0104] (Application process) As shown in Fig. 4, resin powder was applied to the outer peripheral surface of the conductive elastic layer using a transfer roller. Specifically, resin powder (high-density polyethylene (HDPE): Flow Beads (registered trademark) HE-3040 (manufactured by Sumitomo Seika); volume median diameter (Coulter method) 11 μm, melting point (JIS K7121) 130 °C, density (JIS K7112) 0.96 g / cm 3 ) was held on the transfer roller. Note that a metal roller (material: stainless steel (SUS304), surface roughness Ra: 1.5 μm) was used for the transfer roller. The transfer roller is also provided with a regulating blade for adjusting the holding amount of the resin powder, so that the resin powder is leveled and uniformly dispersed. Next, while pressing the roller member against the transfer roller in which the resin powder was dispersed, it was rotated, and a small amount of resin powder (0.1 g or less in mass, 3 mg per 1 cm of the surface area of the conductive elastic layer) was applied to the outer peripheral surface of the conductive elastic layer. 2 per

[0105] (Diffusion process, heating process) In the same manner as in the manufacturing method of the conductive roller No. 1, the resin powder applied to the outer surface of the conductive elastic layer was dispersed over the entire outer peripheral surface of the conductive elastic layer by a diffusion member. After the resin powder was diffused, the roller member was heated in an oven at 160 °C for 20 minutes to fuse the resin powder to the conductive elastic layer, thereby obtaining the conductive roller No. 7.

[0106] Conductive roller No. 8 (Preparation of roller member, ultraviolet irradiation process) A roller member was manufactured in the same manner as in the manufacturing method of the conductive roller No. 1, and the surface of the conductive elastic layer was treated by ultraviolet irradiation.

[0107] (Application process) As shown in Fig. 3, resin powder was applied to the outer peripheral surface of the conductive elastic layer using a transfer plate. Specifically, resin powder (high-density polyethylene (HDPE): Flow Beads (registered trademark) HE-3040 (manufactured by Sumitomo Seika); volume median diameter (Coulter method) 11 μm, melting point (JIS K7121) 130 °C, density (JIS K7112) 0.96 g / cm 3 ) was scattered. The scattered resin powder was leveled and uniformly dispersed using a regulating plate. Note that a metal plate (material: stainless steel (SUS304), surface roughness Ra: 1.5 μm) was used for the transfer plate. Next, the roller member was rolled on the transfer plate in which the resin powder was dispersed, and a small amount of resin powder (0.1 g or less in mass, 3 mg per 1 cm of the surface area of the conductive elastic layer) was applied to the outer peripheral surface of the conductive elastic layer.2 It was applied at 3 mg per hit.

[0108] (Diffusion process, heating process) In the same manner as the manufacturing method of the conductive roller No. 1, the resin powder applied to the outer surface of the conductive elastic layer was diffused over the entire outer peripheral surface of the conductive elastic layer by a diffusion member. After diffusing the resin powder, the roller member was heated in an oven at 160 °C for 20 minutes to fuse the resin powder to the conductive elastic layer, and the conductive roller No. 8 was obtained.

[0109] Conductive roller No. 9 In the diffusion process, the conductive roller No. 9 was obtained in the same manner as the manufacturing method of the conductive roller No. 8, except that the jig was reciprocated a plurality of times in the roller axis direction without rotating the roller member around the axis to diffuse the resin powder.

[0110] Conductive roller No. 10 In the diffusion process, the conductive roller No. 10 was obtained in the same manner as the manufacturing method of the conductive roller No. 8, except that a foamed rubber (inner diameter 14.0 mm) having a cylindrical shape through which the roller member could be inserted was used as the diffusion member, and the pressing force was increased by adjusting the compressed air filled in the tube body of the jig.

[0111] Conductive roller No. 11 In the same manner as the manufacturing method of the conductive roller No. 7, a roller member was fabricated, and after performing surface treatment on the conductive elastic layer by ultraviolet irradiation, a small amount of resin powder (0.1 g or less in mass, per 1 cm of the surface area of the conductive elastic layer 2 It was applied at 3 mg per hit. Thereafter, without diffusing the resin powder, the roller member was heated in an oven at 160 °C for 20 minutes to fuse the resin powder to the conductive elastic layer, and the conductive roller No. 11 was obtained.

[0112] Conductive roller No. 12 In the same manner as the manufacturing method of the conductive roller No. 8, a roller member was produced. After performing surface treatment on the conductive elastic layer by ultraviolet irradiation, a small amount of resin powder (0.1 g or less in mass, 3 mg per 1 cm of the surface area of the conductive elastic layer) was applied to the outer peripheral surface of the conductive elastic layer. 2 Thereafter, without diffusing the resin powder, the roller member was heated in an oven at 160 °C for 20 minutes to fuse the resin powder to the conductive elastic layer, and the conductive roller No. 12 was obtained.

[0113] The evaluation results of the obtained conductive roller are shown in Tables 2 and 3.

[0114]

Table 2

[0115]

Table 3

[0116] For the conductive rollers No. 1 to 4 and 7 to 10, a resin coating layer is formed through an application step, a diffusion step, and a heating step. In these conductive rollers No. 1 to 4 and 7 to 10, the formed resin coating layer is an incomplete film, the change amount of the surface resistance value before and after forming the resin coating layer is small, and the performance of the conductive elastic layer is not inhibited. For these conductive rollers No. 1 to 4 and 7 to 10, the results of the printing test were good.

[0117] For the conductive rollers No. 5 and 6, a resin coating layer is formed by electrostatic coating. In these conductive rollers No. 5 and 6, the formed resin coating layer is a complete film, the change amount of the surface resistance value before and after forming the resin coating layer is large, and the performance of the conductive elastic layer is inhibited. Also, the surface roughness of the conductive elastic layer after forming the resin coating layer was small. For these conductive rollers No. 5 and 6, in the printing test, the image density was not sufficient and there was printing unevenness.

[0118] Conductive rollers No. 11 and 12 are the cases where the resin powder applied to the conductive elastic layer was not diffused using a diffusion member. In these conductive rollers No. 11 and 12, the variation in the thickness of the formed resin coating layer was large, and the variation in the surface roughness of the conductive elastic layer was large. In these conductive rollers No. 11 and 12, there was printing unevenness in the printing test.

[0119] The present invention (1) provides a method for manufacturing a conductive roller, which includes an applying step of applying resin powder to the outer peripheral surface of a conductive elastic layer of a roller member having a conductive shaft core and a conductive elastic layer formed on the outer periphery of the conductive shaft core, a diffusing step of diffusing the resin powder over the entire outer peripheral surface of the conductive elastic layer by a diffusion member, and a heating step of heating the resin powder to fuse the resin powder to the outer peripheral surface of the conductive elastic layer to form an incomplete film.

[0120] The present invention (2) is the method for manufacturing a conductive roller according to the present invention (1), wherein in the diffusing step, the diffusion member is slid while being pressed against the outer peripheral surface of the conductive elastic layer to diffuse the resin powder.

[0121] The present invention (3) is the method for manufacturing a conductive roller according to the present invention (1) or (2), wherein the diffusion member is a cylindrical elastic member through which the roller member can be inserted, and the inner diameter of the cylindrical elastic member is configured to be able to increase or decrease.

[0122] The present invention (4) is the method for manufacturing a conductive roller according to any one of the present inventions (1) to (3), wherein in the diffusing step, while rotating the roller member around its axis, the diffusion member is slid in the axial direction of the roller member on the outer peripheral surface of the conductive elastic layer to diffuse the resin powder.

[0123] The present invention (5) is a method for manufacturing a conductive roller according to any one of the present inventions (1) to (4), wherein the diffusion member is an elastic member, and the Asker-C hardness of the elastic member is 40 or less.

[0124] The present invention (6) is a method for manufacturing a conductive roller according to any one of the present inventions (1) to (5), including an ultraviolet irradiation step of irradiating the surface of the conductive elastic layer with ultraviolet rays before the application step.

[0125] The present invention (7) is a method for manufacturing a conductive roller according to any one of the present inventions (1) to (6), wherein in the application step, the resin powder is applied to the outer peripheral surface of the conductive elastic layer by pressing the conductive elastic layer against a transfer body holding the resin powder.

Explanation of Reference Numerals

[0126] 1: Conductive roller, 2: Conductive shaft core body, 3: Elastic layer, 4: Through hole, 5: Resin coating layer

Claims

1. An applying step of applying resin powder to an outer peripheral surface of the conductive elastic layer with respect to a roller member having a conductive shaft core and a conductive elastic layer formed on an outer periphery of the conductive shaft core; A diffusing step of diffusing the resin powder over the entire outer peripheral surface of the conductive elastic layer by a diffusing member; A method for manufacturing a conductive roller, comprising a heating step of heating the resin powder to fuse the resin powder to the outer peripheral surface of the conductive elastic layer to form an incomplete film.

2. The method for manufacturing a conductive roller according to claim 1, wherein in the diffusing step, the diffusing member is slid while being pressed against the outer peripheral surface of the conductive elastic layer to diffuse the resin powder.

3. The method for manufacturing a conductive roller according to claim 2, wherein the diffusing member is a cylindrical elastic member through which the roller member can be inserted.

4. The method for manufacturing a conductive roller according to claim 1 or 2, wherein in the diffusing step, the resin powder is diffused by sliding the diffusing member in the axial direction of the roller member on the outer peripheral surface of the conductive elastic layer while rotating the roller member around its axis.

5. The method for manufacturing a conductive roller according to claim 3, wherein the diffusing member is an elastic member, and an Asker-C hardness of the elastic member is 40 or less.

6. The method for manufacturing a conductive roller according to claim 1, including an ultraviolet irradiation step of irradiating ultraviolet rays onto a surface of the conductive elastic layer before the applying step.

7. The method for manufacturing a conductive roller according to claim 1, wherein in the applying step, the resin powder is applied to the outer peripheral surface of the conductive elastic layer by pressing the conductive elastic layer against a transfer body holding the resin powder.

Images