Charging member, method of manufacturing charging member, charging device, process cartridge, and image forming apparatus

Abstract

A charging member includes a support member, an elastic layer provided on the support member, an outer layer provided on the elastic layer, and a protective layer provided on the outermost layer of the outer layer. The protective layer contains silica and has a silicon element concentration of 10 atomic% or more, and the outer peripheral surface has a water contact angle of 35 degrees or less.

Description

Technical Field

[0001] The present invention relates to a charging component, a method for manufacturing the charging component, a charging device, a processing box and an image forming device. Background Art

[0002] Japanese Patent Application Laid-Open No. 2003-202733 discloses a charging member having a surface layer formed thereon containing a silicone resin including silicon atoms to which a compound having a hydrophilic group is bonded, wherein the contact angle of the surface of the charging member with respect to water is 25 degrees or less.

[0003] Japanese Patent Application Laid-Open No. 2022-003370 discloses a charging member including a conductive support and a conductive body, wherein the conductive body includes an elastic layer, a resin layer, and a coating layer forming the outermost surface, and the coating layer contains a polysiloxane compound having a Si—O—Zr bond in its molecular structure. Summary of the invention

[0004] The present invention aims to provide a charging member whose surface is less likely to be contaminated and whose outer layer is less likely to crack even after long-term use, compared with a charging member whose silicon concentration in a protective layer is less than 10 atomic % and whose water contact angle on the outer peripheral surface exceeds 35 degrees.

[0005] According to a first aspect of the present invention, a charging component is provided, which comprises: a supporting component; an elastic layer, which is arranged on the supporting component; an outer layer, which is arranged on the elastic layer; and a protective layer, which is the outermost layer arranged on the outer layer, the protective layer contains silicon dioxide and has a silicon element concentration of more than 10 atomic%, and the contact angle of water on the outer peripheral surface is less than 35 degrees.

[0006] According to a second aspect of the present invention, in the charging member according to the first aspect, a contact angle of water on the outer peripheral surface is 25 degrees or less.

[0007] According to a third aspect of the present invention, in the charging member according to the first or second aspect, the silicon element concentration of the protective layer is 20 atomic % or more and 33 atomic % or less.

[0008] According to a fourth aspect of the present invention, in the charging member according to any one of the first to third aspects, the protective layer has a silica content of 25% by mass or more and 100% by mass or less.

[0009] According to a fifth aspect of the present invention, in the charging member according to any one of the first to fourth aspects, the protective layer has a layer thickness of 1 μm or more and 10 μm or less.

[0010] According to the sixth aspect of the present invention, a method for manufacturing a charging component is provided, which is a method for manufacturing the charging component described in any one of the first to fifth aspects, comprising: the steps of preparing a component having a supporting component, an elastic layer, an outer layer and a layer containing silica in sequence; and the steps of bringing alkaline electrolyzed water into contact with the layer containing silica to impart hydroxyl groups to the surface of the layer containing silica to form a protective layer.

[0011] According to a seventh aspect of the present invention, there is provided a charging device comprising the charging component according to any one of the first to fifth aspects.

[0012] According to the eighth aspect of the present invention, there is provided a processing box comprising: a photosensitive body; a charging device, the charging device having a charging component as described in any one of the first to fifth aspects, the charging component contacts the surface of the photosensitive body to charge it; and an electrostatic latent image forming device, the electrostatic latent image forming device forms an electrostatic latent image on the surface of the charged photosensitive body, and the processing box can be loaded and unloaded on the image forming device.

[0013] According to the ninth aspect of the present invention, there is provided an image forming device, characterized in that it comprises: a photosensitive body; a charging device, the charging device having the charging component described in any one of the first to fifth aspects, the charging component being in contact with the surface of the photosensitive body to charge it; an electrostatic latent image forming device, the electrostatic latent image forming device forming an electrostatic latent image on the surface of the charged photosensitive body; a developing device, the developing device using a developer containing a colorant to develop the electrostatic latent image formed on the surface of the photosensitive body to form a colorant image; and a transfer device, the transfer device transferring the colorant image to the surface of a recording medium.

[0014] (Effect)

[0015] According to the first, fourth or fifth aspect, a charging component is provided, which is less likely to be contaminated on the surface and less likely to crack on the outer layer even if used for a long time, compared with a charging component whose silicon concentration in the protective layer is less than 10 atomic % and whose water contact angle on the outer peripheral surface exceeds 35 degrees.

[0016] According to the second aspect, there is provided a charging member whose surface is less likely to be contaminated even in long-term use, compared with a charging member whose outer peripheral surface has a water contact angle exceeding 25 degrees.

[0017] According to the third aspect, there is provided a charging member whose outer layer is less likely to crack even after long-term use, compared with a charging member having a protective layer with a silicon element concentration of less than 20 atomic %.

[0018] According to the sixth aspect, there is provided a method for producing a charging member which is less likely to be contaminated on the surface and less likely to have cracks in the outer layer even when used for a long period of time, compared with a method in which alkaline electrolyzed water is not brought into contact with a layer containing silicon dioxide.

[0019] According to the seventh aspect, a charging device is provided, which has a charging component, and the surface of the charging component is not easily contaminated and the outer layer is not easily cracked even after long-term use, compared with the case where the silicon concentration of the protective layer of the charging component is lower than 10 atomic% and the contact angle of water on the outer peripheral surface exceeds 35 degrees.

[0020] According to the eighth aspect, a processing box is provided, which has a charging component, and the surface of the charging component is not easily contaminated and the outer layer is not easily cracked even after long-term use, compared with the case where the silicon concentration of the protective layer of the charging component is lower than 10 atomic% and the contact angle of water on the outer peripheral surface exceeds 35 degrees.

[0021] According to the ninth aspect, an image forming device is provided, which has a charging component, and the surface of the charging component is not easily contaminated and the outer layer is not easily cracked even if it is used for a long time, compared with the case where the silicon concentration of the protective layer of the charging component is lower than 10 atomic% and the contact angle of water on the outer peripheral surface exceeds 35 degrees. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a schematic perspective view showing an example of a charging member according to the present embodiment;

[0023] Figure 2 is a schematic cross-sectional view showing an example of a charging member according to this embodiment. Figure 1 AA section view;

[0024] Figure 3 is a schematic structural diagram showing an example of an image forming apparatus according to the present embodiment;

[0025] Figure 4 FIG. 2 is a schematic diagram showing another example of the image forming apparatus according to the present embodiment. DETAILED DESCRIPTION

[0026] The following describes embodiments of the present invention. These descriptions and examples are intended to illustrate the embodiments and do not limit the scope of the embodiments.

[0027] In the present invention, a numerical range expressed using "to" means a range including the numerical values ​​described before and after "to" as the minimum value and the maximum value, respectively.

[0028] In the numerical range recorded in stages in the present invention, the upper limit or lower limit recorded in a numerical range can also be replaced by the upper limit or lower limit of the numerical range recorded in other stages. In addition, in the numerical range recorded in the present invention, the upper limit or lower limit of this numerical range can also be replaced by the value shown in the embodiment.

[0029] In the present invention, the term "process" refers not only to an independent process but also to a process that cannot be clearly distinguished from other processes as long as the purpose of the process can be achieved.

[0030] In the present invention, when the embodiments are described with reference to the drawings, the structure of the embodiments is not limited to the structure shown in the drawings. In addition, the sizes of the components in each figure are conceptual sizes, and the relative relationship between the sizes of the components is not limited to this.

[0031] In the present invention, each component may also include a plurality of corresponding substances. In the present invention, when referring to the amount of each component in the composition, if there are a plurality of substances that meet the requirements of each component in the composition, unless otherwise specified, it refers to the total amount of the plurality of substances present in the composition.

[0032] In the present invention, multiple types of particles corresponding to each component may be included. When multiple types of particles corresponding to each component are present in the composition, the particle size of each component refers to a value related to a mixture of the multiple types of particles present in the composition unless otherwise specified.

[0033] In the present invention, the "axial direction" of the charging member refers to the direction in which the rotation axis of the charging member extends, and the "circumferential direction" of the charging member refers to the rotation direction of the charging member.

[0034] <Charging parts>

[0035] The charging member of this embodiment includes a supporting member, an elastic layer provided on the supporting member, an outer layer provided on the elastic layer, and a protective layer provided on the outer layer.

[0036] Figure 1 It is a schematic perspective view showing an example of a charging member according to this embodiment. Figure 2 yes Figure 1 The AA section view is cut along the radial direction. Figure 1 A cross-sectional view of a charging member is illustrated.

[0037] Figure 1 The charging member 30 shown is a roll-shaped charging member. The charging member 30 has a structure in which an elastic layer 34, an outer layer 36, and a protective layer 38 are sequentially stacked on a supporting member 32. The charging member 30 may have an adhesive layer (not shown) between the supporting member 32 and the elastic layer 34.

[0038] The shape of the charging member in this embodiment is not limited to a roll shape, and may be a belt shape, a tube shape, a blade shape, or the like.

[0039] In the charging member of this embodiment, the protective layer contains silicon dioxide (Silica, SiO2) with a silicon element concentration of 10 atomic % or more, and the water contact angle of the outer peripheral surface is 35 degrees or less.

[0040] The charging member of this embodiment is unlikely to be contaminated on the surface and is unlikely to have cracks in the outer layer even when used for a long period of time. The reasons for this are presumed as follows.

[0041] When image formation is performed for a long time, dirt accumulates on the surface of the charging component. This dirt mainly originates from the toner, and contains components of the toner base particles and components of the toner external additives. The surface dirt of the charging component is easily generated in the charging component of the type that contacts the surface of the photoreceptor, and sometimes it is generated in the charging component of the type that does not contact the surface of the photoreceptor due to electrostatic adsorption of the toner.

[0042] The dirt on the surface of the charging component causes the resistance of the area to increase, and the charging uniformity of the charging component is reduced. As a result, image defects such as uneven image density and undesirable streaky images may occur. In addition, when the charging component contacts other components (for example, a photoreceptor, a cleaning component of the charging component), stress is concentrated on the dirt-attached portion of the surface of the charging component, so cracks may sometimes be generated in the outer layer of the charging component starting from the dirt-attached portion.

[0043] The charging member of this embodiment has a protective layer containing silicon dioxide, and the silicon element concentration of the protective layer is 10 atomic % or more, thereby suppressing the accumulation of dirt mainly composed of toner.

[0044] In addition, silicon has the effects of corrosion resistance and degradation resistance. The silicon concentration of the protective layer is 10 atomic % or more, thereby suppressing the degradation of the resin of the outer layer due to discharge and suppressing the generation of cracks in the outer layer.

[0045] In addition, it is presumed that the charging member of this embodiment can suppress the adhesion of dirt and maintain charging uniformity by setting the water contact angle of the outer peripheral surface to 35 degrees or less, that is, arranging hydrophilic groups (such as hydroxyl groups) to cover the outer peripheral surface.

[0046] In the charging member of this embodiment, from the viewpoint of suppressing the accumulation of dirt mainly composed of toner and suppressing the degradation of the resin of the outer layer due to discharge, the silicon concentration of the protective layer is 10 atomic % or more, preferably 15 atomic % or more, and more preferably 20 atomic % or more.

[0047] In the charging member of this embodiment, the silicon concentration of the protective layer may be 33 atomic % or less, 30 atomic % or less, or 25 atomic % or less.

[0048] In the charging member of this embodiment, from the viewpoint of suppressing the adhesion of dirt, the water contact angle of the outer peripheral surface is 35 degrees or less, preferably 30 degrees or less, and more preferably 25 degrees or less. From the viewpoint of suppressing the adhesion of dirt, the lower the water contact angle of the outer peripheral surface, the better.

[0049] In the charging member of this embodiment, the contact angle of water on the outer peripheral surface may be 0 degrees or more, 10 degrees or more, or 15 degrees or more.

[0050] The silicon concentration of the protective layer of the charging member was determined by analyzing the element composition of the protective layer using SEM-EDX (Scanning Electron Microscopy with Energy Dispersive X-ray Spectroscopy). The specific analysis method is as follows.

[0051] At the axial center of the charging component, the protective layer is peeled off from the supporting component and used as a sample. In the case where it is difficult to peel off only the protective layer, the outer layer and the protective layer are peeled off and used as a sample. The thickness of the protective layer is measured, and the detection depth of the SEM-EDX is adjusted so that the protective layer becomes the analysis object.

[0052] The EDX device (Horiba EMAX ENERGY, detector: X-Max80mm) was used. 2 ) was used to photograph the sample at a magnification of 150. The accelerating voltage of the SEM was 20 kV. Three fields of view were photographed in a rectangular shape of 0.8 mm in the axial direction and 1.4 mm in the circumferential direction. All detected elements were quantified to determine the ratio of silicon element (atomic %) in the protective layer.

[0053] The contact angle of water on the outer peripheral surface of the charging member was measured as follows.

[0054] The charging member was placed in an environment of 22° C. and 55% relative humidity for 24 hours or more to adjust the temperature and humidity.

[0055] In an environment with a temperature of 22°C and a relative humidity of 55%, the axial direction of the charging component is fixed in a horizontal direction, and a 1.0 μL drop of ion exchange water is dripped onto the vertex in the axial center of the charging component. The contact angle after dripping for 10 seconds is measured by the drop method. The dripping of water and the measurement of the contact angle are performed using an automatic contact angle measuring device (Kyowa Interface Science CA-X). Four positions are measured in 90° increments on the circumference of the charging component, and the four measured values ​​are arithmetic averaged.

[0056] Next, each layer of the charging member will be described in detail.

[0057] [Supporting parts]

[0058] The supporting member is a conductive member that functions as an electrode and a supporting body of the charging member. The supporting member may be a hollow member or a non-hollow member, for example, a rod-shaped, cylindrical or endless belt-shaped member.

[0059] As supporting parts, there can be cited metal parts such as iron (free-cutting steel, etc.), copper, copper alloys, brass, stainless steel, aluminum, nickel, etc.; iron parts plated with chromium, nickel, etc.; parts with the outer peripheral surface of resin or ceramic parts plated; resin or ceramic parts containing conductive agents, etc.

[0060] [Elastic layer]

[0061] Preferably, the elastic layer has electrical conductivity and a volume resistivity of 1×10 3 Ωcm or more 1×10 14 Ωcm or less.

[0062] The volume resistivity of the elastic layer is a value measured by the following method.

[0063] A sheet-shaped measurement sample was taken from the elastic layer, and a voltage adjusted to an electric field (applied voltage / composition sheet thickness) of 1000 V / cm was applied for 30 seconds using a measurement jig (R12702A / B resistance meter box: manufactured by Advantest) and a high resistance measuring instrument (R8340A digital high resistance / small range ammeter: manufactured by Advantest) according to JIS K 6911 (1995). The current value was read and calculated using the following formula.

[0064] Volume resistivity (Ωcm) = (19.63 × applied voltage (V)) / (current value (A) × test sample thickness (cm))

[0065] The elastic layer may be a foamed elastic layer or a non-foamed elastic layer. The elastic layer may be directly disposed on the outer peripheral surface of the supporting member or may be disposed on the outer peripheral surface of the supporting member via an adhesive layer.

[0066] One embodiment of the elastic layer includes an elastic material, a conductive agent, and other additives.

[0067] As the elastic material, for example, polyurethane, nitrile rubber, isoprene rubber, butadiene rubber, ethylene-propylene rubber, ethylene-propylene-diene rubber, epichlorohydrin rubber, epichlorohydrin-ethylene oxide rubber, epichlorohydrin-ethylene oxide-allyl glycidyl ether rubber, styrene-butadiene rubber, acrylonitrile-butadiene rubber, chloroprene rubber, chlorinated polyisoprene, hydrogenated polybutadiene, butyl rubber, silicone rubber, fluororubber, natural rubber, and elastic materials obtained by mixing two or more of them can be cited. Among these elastic materials, polyurethane, silicone rubber, ethylene-propylene-diene rubber, epichlorohydrin-ethylene oxide rubber, epichlorohydrin-ethylene oxide-allyl glycidyl ether rubber, acrylonitrile-butadiene rubber, and elastic materials obtained by mixing two or more of them are also preferred.

[0068] As the conductive agent, there are electronic conductive agents and ionic conductive agents. As the electronic conductive agent, there are carbon blacks such as furnace black, thermal black, channel black, Ketjen black, acetylene black, and pigment carbon black; pyrolytic carbon; graphite; metals or alloys such as aluminum, copper, nickel, and stainless steel; metal oxides such as tin oxide, indium oxide, titanium oxide, tin oxide-antimony oxide solid solution, and tin oxide-indium oxide solid solution; powders of materials subjected to conductive treatment on the surface of insulating materials. As the ionic conductive agent, there are perchlorates or chlorates such as tetraethylammonium, lauryltrimethylammonium, and benzyltrialkylammonium; perchlorates or chlorates of alkali metals or alkaline earth metals such as lithium and magnesium, etc. The conductive agent can be used alone or in combination of two or more.

[0069] The total content of the conductive agent contained in the elastic layer is preferably set so as to roughly target the volume resistivity of the elastic layer.

[0070] When an electronic conductive agent is used as the conductive agent, for example, the total amount of the electronic conductive agent may be 1 part by mass or more and 20 parts by mass or less, or 3 parts by mass or more and 20 parts by mass or less, based on 100 parts by mass of the elastic material.

[0071] When an ion conductive agent is used as the conductive agent, for example, the total amount of the ion conductive agent may be 0.1 parts by mass or more and 10 parts by mass or less, or 0.5 parts by mass or less and 5 parts by mass or less, based on 100 parts by mass of the elastic material.

[0072] The average primary particle size of the conductive agent is preferably 1 nm to 500 nm, more preferably 5 nm to 200 nm. The average primary particle size of the conductive agent is determined by observing the cross section of the elastic layer with an electron microscope, measuring the major axes of 100 conductive agents, and averaging the major axes.

[0073] As the conductive agent, carbon black is preferred. The average primary particle size of the carbon black is preferably 1 nm or more and 500 nm or less, and more preferably 5 nm or more and 200 nm or less.

[0074] The content of carbon black is preferably 1 part by mass or more and 20 parts by mass or less, and more preferably 3 parts by mass or more and 10 parts by mass or less, based on 100 parts by mass of the elastic material.

[0075] Examples of other additives include vulcanizing agents, vulcanization accelerators, vulcanization accelerating aids, fillers, softeners, plasticizers, curing agents, antioxidants, surfactants, coupling agents, and the like.

[0076] Examples of the filler include calcium carbonate, silicon dioxide, and clay minerals. The filler may be used alone or in combination of two or more.

[0077] The filler is preferably calcium carbonate, and the content of calcium carbonate is preferably 1 part by mass or more and 50 parts by mass or less, and more preferably 10 parts by mass or more and 40 parts by mass or less, based on 100 parts by mass of the elastic material.

[0078] The thickness of the elastic layer is preferably 1 mm or more and 10 mm or less, and more preferably 2 mm or more and 5 mm or less.

[0079] The cross section of the elastic layer was photographed with an electron microscope to measure the thickness of the elastic layer. The value obtained by measuring four locations at 90° increments in the circumferential direction from the axial center of the charging member and calculating the arithmetic average was used as the thickness of the elastic layer.

[0080] As a method for forming an elastic layer on a supporting member, for example, there can be mentioned: a method in which a composition for forming an elastic layer, which is a mixture of an elastic material, a conductive agent, and other additives, is extruded from an extruder together with a cylindrical supporting member to form a layer of the composition for forming an elastic layer on the outer peripheral surface of the supporting member, and then the layer of the composition for forming an elastic layer is heated to undergo a cross-linking reaction (including vulcanization) to form an elastic layer; a method in which a composition for forming an elastic layer, which is a mixture of an elastic material, a conductive agent, and other additives, is extruded from an extruder to the outer peripheral surface of an endless belt-shaped supporting member to form a layer of the composition for forming an elastic layer on the outer peripheral surface of the supporting member, and then the layer of the composition for forming an elastic layer is heated to undergo a cross-linking reaction (including vulcanization) to form an elastic layer, etc. The supporting member may also have an adhesive layer on its outer peripheral surface.

[0081] [Adhesive layer]

[0082] An adhesive layer may be present between the supporting member and the elastic layer for bonding the two.

[0083] As the adhesive layer between the supporting member and the elastic layer, specifically, there can be mentioned a layer containing resins such as polyolefin resin, acrylic resin, epoxy resin, polyurethane, nitrile rubber, chlorinated rubber, vinyl chloride resin, vinyl acetate resin, polyester resin, phenol resin, silicone resin, etc. The adhesive layer may also contain a conductive agent (for example, the above-mentioned electronic conductive agent or ion conductive agent).

[0084] From the viewpoint of adhesion between the elastic layer and the supporting member, the thickness of the adhesive layer is preferably 1 μm to 50 μm, more preferably 2 μm to 40 μm, and further preferably 5 μm to 20 μm.

[0085] The thickness of the adhesive layer was measured by photographing a cross section using an electron microscope. The thickness of the adhesive layer was measured at four locations in 90° increments in the circumferential direction of the axial center of the charging member and the arithmetic average was taken as the thickness of the adhesive layer.

[0086] [Outer layer]

[0087] Preferably, the outer layer has electrical conductivity and a volume resistivity of 1×10 3 Ωcm or more and 1×10 14 The volume resistivity of the outer layer is a value measured by the same method as the volume resistivity of the elastic layer.

[0088] One embodiment of the outer layer includes a resin, a conductive agent, and other additives.

[0089] As the resin contained in the outer layer, there can be mentioned copolymerized nylon resin, polyamide resin, polyimide resin, polyamideimide resin, polyester resin, polyethylene terephthalate resin, polyarylate resin, polycarbonate resin, polyethylene resin, polyurethane resin, phenol resin, silicone resin, acrylic resin, fluorine-modified acrylic resin, silicone-modified acrylic resin, melamine resin, epoxy resin, fluororesin, polyvinylidene fluoride resin, tetrafluoroethylene resin, polyvinyl butyral resin, ethylene-tetrafluoroethylene copolymer resin, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin, tetrafluoroethylene-hexafluoropropylene copolymer resin, fluororubber resin, polyethylene resin, polyvinyl alcohol resin, polyvinyl acetal resin, polyvinylidene chloride resin, polyvinyl chloride resin, ethylene-vinyl acetate copolymer resin, cellulose, polythiophene resin, a resin obtained by mixing two or more of these, a resin obtained by curing or crosslinking at least one of these by a curing agent or a catalyst, etc. The resin can be used alone or in combination of two or more.

[0090] From the viewpoint of suppressing the contamination of the outer layer, polyamide resin, polyvinylidene fluoride resin, and tetrafluoroethylene resin are preferred, and polyamide resin is more preferred. As polyamide, from the viewpoint of suppressing the contamination of the outer layer, alcohol-soluble polyamide is preferred, alkoxymethylated polyamide (alkoxymethylated nylon) is more preferred, and methoxymethylated polyamide (methoxymethylated nylon) is further preferred.

[0091] The conductive agent contained in the outer layer preferably has a volume resistivity of 1×10 9 Conductive particles with a particle size of Ωcm or less. Examples of the conductive particles include metal oxides such as tin oxide, titanium oxide, and zinc oxide; and carbon black.

[0092] The conductive particles contained in the outer layer preferably have a primary particle size of 10 nm or more and 50 nm or less from the viewpoint of excellent dispersibility in the resin.

[0093] The content of the conductive particles in the outer layer is preferably 5 parts by mass or more and 50 parts by mass or less, and more preferably 10 parts by mass or more and 30 parts by mass or less, based on 100 parts by mass of the resin.

[0094] The outer layer may contain particles for forming unevenness in order to provide fine unevenness on the surface. The particles for forming unevenness may be inorganic particles or organic particles.

[0095] As the concavoconvex forming particles, for example, inorganic particles such as silica particles, alumina particles, and zircon particles; resin particles such as polyamide resin particles, fluororesin particles, and silicone resin particles can be cited. From the viewpoint of reducing the contamination of the charging component, resin particles are preferred, and polyamide resin particles are more preferred. The concavoconvex forming particles can be used alone or in combination of two or more.

[0096] The volume average particle size of the concavoconvex forming particles is preferably 5 μm or more and 20 μm or less, more preferably 5 μm or more and 10 μm or less. The volume average particle size of the concavoconvex forming particles is determined as follows: the cross section of the outer layer is observed using an electron microscope, the major diameter of 100 particles is measured, and the particle size distribution based on volume is prepared assuming that they are spheres. The volume average particle size refers to the 50% particle size accumulated from the small diameter side.

[0097] When the outer layer contains the concavoconvex forming particles, the content of the concavoconvex forming particles is preferably 5 parts by mass or more and 30 parts by mass or less, and more preferably 8 parts by mass or more and 20 parts by mass or less, based on 100 parts by mass of the resin.

[0098] As for the outer layer, it is preferred that the layer contains 5 parts by mass or more and 30 parts by mass or less of particles having a volume average particle size of 5 μm or more and 20 μm or less per 100 parts by mass of the resin, and it is more preferred that the layer contains 8 parts by mass or more and 20 parts by mass or less of particles having a volume average particle size of 5 μm or more and 10 μm or less per 100 parts by mass of the resin.

[0099] Examples of other additives include vulcanizing agents, vulcanization accelerators, vulcanization accelerating aids, fillers, softeners, plasticizers, curing agents, antioxidants, surfactants, coupling agents, and the like.

[0100] The thickness of the outer layer is preferably 1 μm or more and 25 μm or less, preferably 2 μm or more and 20 μm or less, and more preferably 3 μm or more and 15 μm or less.

[0101] The thickness of the outer layer was measured by photographing a cross section using an electron microscope. The thickness of the outer layer was measured at four locations in 90° increments in the circumferential direction at the center of the axial direction of the charging member and the arithmetic average was taken as the thickness of the outer layer.

[0102] As a method for forming the outer layer on the elastic layer, for example, a method of coating a composition for forming an outer layer in which a resin, a conductive agent, unevenness forming particles, and other additives are mixed on the outer peripheral surface of the elastic layer to form a layer of the composition for forming an outer layer, and then drying the layer of the composition for forming an outer layer. As a method for coating the composition for forming an outer layer on the outer peripheral surface of the elastic layer, for example, dip coating, roll coating, knife coating, wire bar coating, spray coating, weld coating, air knife coating, curtain coating, etc. can be mentioned.

[0103] [Protective layer]

[0104] The protective layer is a layer containing silicon dioxide (Silica, SiO2).

[0105] The protective layer may also contain compounds other than silicon dioxide. Examples of compounds other than silicon dioxide include resins such as polyester resins and styrene acrylic resins; inorganic particles such as waxes, titanium dioxide (TiO2) and aluminum oxide (Al2O3); higher fatty acid metal salts; and components modified from these compounds.

[0106] From the viewpoint of suppressing the accumulation of dirt mainly composed of toner and suppressing the degradation of the resin of the outer layer due to discharge and suppressing the generation of cracks in the outer layer, the silica content of the protective layer is preferably 25 mass % or more, more preferably 35 mass % or more, and further preferably 45 mass % or more.

[0107] The silicon dioxide content of the protective layer may be 100% by mass, 85% by mass or less, or 70% by mass or less.

[0108] From the viewpoint of protecting the outer layer, the thickness of the protective layer is preferably 1 μm or more, more preferably 2 μm or more, and further preferably 4 μm or more.

[0109] From the viewpoint of ensuring the charging performance of the charging member, the thickness of the protective layer is preferably 10 μm or less, more preferably 8 μm or less, and further preferably 6 μm or less.

[0110] The thickness of the protective layer was measured by photographing a cross section of the protective layer using an electron microscope. The thickness of the protective layer was determined by measuring four locations at 90° increments in the circumferential direction of the charging member in the axial center and arithmetically averaging the values.

[0111] The method for forming the protective layer is not particularly limited. As an example of the method for forming the protective layer, there can be mentioned a method of sequentially performing a silicon dioxide-containing layer forming step and a surface treatment step described later.

[0112] <Method for manufacturing charging member>

[0113] As a method for producing the charging member of this embodiment, for example, the following embodiments can be cited.

[0114] An example of an implementation method of a method for manufacturing a charging component includes: a step of preparing a component having a supporting component, an elastic layer, an outer layer, and a layer containing silica in sequence; and a step of bringing alkaline electrolyzed water into contact with the layer containing silica to impart hydroxyl groups to the surface of the layer containing silica to form a protective layer (surface treatment step).

[0115] Hereinafter, the “layer containing silicon dioxide” is also referred to as a “silicon dioxide-containing layer”.

[0116] As an example of an embodiment of preparing a member having a supporting member, an elastic layer, an outer layer, and a silica-containing layer in this order, a charging member can be removed from an image forming apparatus after use. When the member having a supporting member, an elastic layer, and an outer layer in this order is continuously used as a charging member, toner is transferred from the photoreceptor to the outer layer of the charging member, and a silica-containing layer containing a component derived from silica particles as a toner external additive is formed on the outer layer.

[0117] The charging member removed from the used image forming apparatus can be regenerated by subjecting the charging member to a surface treatment step using alkaline electrolyzed water. The charging member in this case can be referred to as a regenerated charging member.

[0118] As an example of an implementation of preparing a component having a supporting component, an elastic layer, an outer layer and a silica-containing layer in sequence, there can be cited a method of forming a silica-containing layer on the outer layer of a component having a supporting component, an elastic layer and an outer layer in sequence (silicon dioxide-containing layer forming step).

[0119] [Silicon dioxide-containing layer forming step]

[0120] The member having a supporting member, an elastic layer, and an outer layer in this order is obtained by forming the elastic layer on the supporting member and forming the outer layer on the elastic layer. The specific methods of forming the elastic layer on the supporting member and the method of forming the outer layer on the elastic layer are as described above. The supporting member and the elastic layer may also be bonded together using an adhesive layer.

[0121] The silicon dioxide-containing layer forming step is a step of forming a silicon dioxide-containing layer (original film of the protective layer) on the outer layer of the member, and the silicon dioxide-containing layer is formed so that the silicon element concentration of the silicon dioxide-containing layer is 10 atomic % or more.

[0122] Examples of a method for forming the silicon dioxide-containing layer include known film-forming methods such as plasma CVD (Chemical Vapor Deposition), vacuum evaporation, sputtering, and ion plating using silicon dioxide (Silica, SiO 2 ) as a material.

[0123] As another method for forming a silica-containing layer, a member having a supporting member, an elastic layer, and an outer layer in sequence is mounted on a mounting portion of a charging member in an electrophotographic image forming apparatus, the image forming apparatus is operated, and an image is formed using a toner to which silica particles are added. That is, the image formation is performed using the member as a charging member. According to this method, the toner is transferred from the photoreceptor to the outer layer of the member, and a silica-containing layer containing components derived from silica particles as an external additive of the toner is formed on the outer layer.

[0124] The image forming apparatus used in the above method may be of a type in which the charging member is not in contact with the photoreceptor (the charging member electrostatically attracts the toner), but a type in which the charging member is in contact with the photoreceptor is effective.

[0125] In the above method, the silicon concentration of the silicon dioxide-containing layer can be adjusted according to the amount of image formation. There is a tendency that the silicon concentration of the silicon dioxide-containing layer increases as the amount of image formation increases.

[0126] The toner used in the above method only needs to be added with silica particles, and the toner mother particles and other external additives are not limited. The toner mother particles contain, for example, a binder resin such as a polyester resin, a styrene acrylic resin, and a release agent (various waxes). The toner mother particles may contain a colorant or may not contain a colorant. Other external additives include, for example, inorganic particles such as titanium dioxide (TiO2) and aluminum oxide (Al2O3); cleaning activators (for example, higher fatty acid metal salts represented by zinc stearate), etc.

[0127] [Surface treatment process]

[0128] The surface treatment step is a step of bringing alkaline electrolyzed water into contact with the silicon dioxide-containing layer to impart hydroxyl groups to the surface of the silicon dioxide-containing layer to form a protective layer. The surface treatment is performed so that the contact angle of water on the surface of the protective layer (i.e., the outer peripheral surface of the charging member) becomes 35 degrees or less.

[0129] Alkaline electrolytic water is water produced by electrolyzing water. When the alkaline electrolytic water is brought into contact with the silicon dioxide-containing layer, hydroxyl groups (—OH) are provided to the surface of the silicon dioxide-containing layer, and the contact angle of water on the surface is reduced.

[0130] Examples of a method for bringing the silicon dioxide-containing layer into contact with alkaline electrolyzed water include dip coating, spray coating, etc. It is preferred that the silicon dioxide-containing layer be brought into contact with alkaline electrolyzed water and then dried at room temperature.

[0131] The contact angle of water on the surface of the protective layer (ie, the outer peripheral surface of the charging member) can be adjusted by the pH of the alkaline electrolytic water and the time for which the silicon dioxide-containing layer is in contact with the alkaline electrolytic water.

[0132] From the viewpoint of the efficiency of providing hydroxyl groups, the pH of the alkaline electrolyzed water is preferably pH 10 or higher, and more preferably pH 11 or higher.

[0133] The pH of the alkaline electrolyzed water is preferably pH 12 or less from the viewpoint of not causing corrosion of the supporting member and not causing modification of the outer layer and the elastic layer.

[0134] The contact time of the silicon dioxide-containing layer and the alkaline electrolyzed water is preferably adjusted according to the pH of the alkaline electrolyzed water. When the alkaline electrolyzed water has a pH of 12, the contact time is preferably 30 seconds or more and 30 minutes or less.

[0135] <Charging device, image forming device, process cartridge>

[0136] The charging device of this embodiment has the charging component of this embodiment. The charging device of this embodiment can be a charging device in which the charging component contacts the surface of the photoreceptor, or a charging device in which the charging component does not contact the surface of the photoreceptor. In the charging device in which the charging component contacts the surface of the photoreceptor, the effect achieved by this embodiment (the surface of the charging component is not easily contaminated and the outer layer is not easily cracked) is significant.

[0137] The image forming device of the present embodiment comprises a photoreceptor, a charging device for charging the surface of the photoreceptor, an electrostatic latent image forming device for forming an electrostatic latent image on the surface of the charged photoreceptor, a developing device for developing the electrostatic latent image formed on the surface of the photoreceptor by a developer containing a colorant to form a colorant image, and a transfer device for transferring the colorant image to the surface of a recording medium. Moreover, as a charging device, a charging device having a charging component of the present embodiment is applied. The charging device may be a charging device in which the charging component is in contact with the surface of the photoreceptor, or a charging device in which the charging component is not in contact with the surface of the photoreceptor. In the charging device in which the charging component is in contact with the surface of the photoreceptor, the effect achieved by the present embodiment (the surface of the charging component is not easily contaminated and the outer layer is not easily cracked) is significant.

[0138] In the image forming apparatus of the present embodiment, for example, the portion having the photoreceptor and the charging device may also be a box structure that is detachable from the image forming apparatus (i.e., the processing box of the present embodiment). In the processing box, in addition to the photoreceptor and the charging device, for example, at least one selected from the group consisting of an electrostatic latent image forming device, a developing device, and a transfer device may be provided. The charging device may be a charging device in which the charging component contacts the surface of the photoreceptor, or a charging device in which the charging component does not contact the surface of the photoreceptor. In the charging device in which the charging component contacts the surface of the photoreceptor, the effect achieved by the present embodiment (the surface of the charging component is not easily contaminated and the outer layer is not easily cracked) is significant.

[0139] The image forming device of the present embodiment is applicable to: a device equipped with a fixing device for fixing the colorant image transferred to the surface of a recording medium; a device of a direct transfer method for directly transferring the colorant image formed on the surface of a photosensitive body to a recording medium; a device of an intermediate transfer method for transferring the colorant image formed on the surface of a photosensitive body once to the surface of an intermediate transfer body, and for a second time transferring the colorant image transferred to the surface of the intermediate transfer body to the surface of a recording medium; a device equipped with a cleaning device for cleaning the surface of a photosensitive body before charging after the transfer of the colorant image; a device equipped with a static elimination device for eliminating static by irradiating the surface of a photosensitive body before charging with static elimination light after the transfer of the colorant image; a device equipped with a photosensitive body heating component for increasing the temperature of the photosensitive body and reducing the relative humidity, and the like.

[0140] In the case of an intermediate transfer method device, the transfer device may include, for example, an intermediate transfer body for transferring a colorant image to a surface, a primary transfer device for transferring the colorant image formed on the surface of a photosensitive body to the surface of the intermediate transfer body, and a secondary transfer device for secondary transferring the colorant image transferred to the surface of the intermediate transfer body to the surface of a recording medium.

[0141] The image forming apparatus of the present embodiment may be any of a dry developing system image forming apparatus and a wet developing system (development system using a liquid developer) image forming apparatus.

[0142] An example of the image forming apparatus according to the present embodiment is shown below, but the present invention is not limited thereto. The main parts shown in the figure are described, and the description of the others is omitted.

[0143] Figure 3 This is a schematic configuration diagram showing an example of the image forming apparatus according to the present embodiment.

[0144] like Figure 3 As shown, the image forming apparatus 100 of the present embodiment includes a process cartridge 300, an exposure device 9 (an example of an electrostatic latent image forming device), a transfer device 40 (a primary transfer device), and an intermediate transfer body 50. In the image forming apparatus 100, the exposure device 9 is arranged at a position capable of exposing the photosensitive body 7 from the opening of the process cartridge 300, and the transfer device 40 is arranged at a position opposite to the photosensitive body 7 via the intermediate transfer body 50, and the intermediate transfer body 50 is arranged so that a part thereof contacts the photosensitive body 7. Although not shown in the figure, a secondary transfer device is also provided for transferring the toner image transferred to the intermediate transfer body 50 to a recording medium (e.g., paper). The intermediate transfer body 50, the transfer device 40 (a primary transfer device), and the secondary transfer device (not shown) correspond to an example of a transfer device.

[0145] Figure 3 The process box 300 in the embodiment integrally supports the photoreceptor 7, the charging device 8, the developing device 11 and the cleaning device 13 in the housing. The cleaning device 13 has a cleaning blade (an example of a cleaning member) 131, and the cleaning blade 131 is arranged to contact the surface of the photoreceptor 7. The cleaning member may be a conductive or insulating fibrous member instead of the cleaning blade 131, and the cleaning member may be used alone or in combination with the cleaning blade 131.

[0146] exist Figure 3 In the example shown, as the image forming apparatus, a fibrous member 132 (rolled shape) for supplying the lubricant 14 to the surface of the photoreceptor 7 and a fibrous member 133 (flat brush shape) for assisting cleaning are provided, but they are arranged as needed.

[0147] Next, each structure of the image forming apparatus according to this embodiment will be described.

[0148] - Photoreceptor -

[0149] The photoreceptor 7 has a structure in which, for example, an undercoat layer and a photosensitive layer are sequentially laminated on a conductive substrate. The photosensitive layer may be a single-layer photosensitive layer or a laminated photosensitive layer composed of a charge generating layer and a charge transporting layer.

[0150] - Charging device -

[0151] The charging device 8 has the charging member of this embodiment. The charging device 8 may be a charging device in which the charging member is in contact with the surface of the photoreceptor, or a charging device in which the charging member is not in contact with the surface of the photoreceptor. The charging device 8 may be any of a charging device in which only a direct current voltage is applied to the charging member (DC charging method), a charging device in which only an alternating current voltage is applied to the charging member (AC charging method), and a charging device in which a voltage obtained by superimposing an alternating current voltage on a direct current voltage is applied to the charging member (AC / DC charging method).

[0152] - Exposure device -

[0153] As the exposure device 9, for example, an optical system device that exposes light such as semiconductor laser, LED light, liquid crystal shutter light to the surface of the photoreceptor 7 in a predetermined image shape can be cited. The wavelength of the light source is set to be within the spectral sensitivity region of the photoreceptor. As the wavelength of the semiconductor laser, near-infrared with an oscillation wavelength near 780nm is the mainstream. However, it is not limited to this wavelength. As an oscillation wavelength laser or a blue laser of about 600nm, a laser with an oscillation wavelength of more than 400nm and less than 450nm can also be used. In addition, a surface-emitting laser light source of the type that can output multiple beams is also effective for forming a color image.

[0154] - Development device -

[0155] As the developing device 11, for example, a common developing device that develops the photosensitive body 7 by contacting or non-contacting the developer can be cited. As the developing device 11, there is no particular limitation as long as it has the above-mentioned functions, and it can be selected according to the purpose. For example, a known developer having a function of attaching a single-component developer or a two-component developer to the photosensitive body 7 using a brush, a roller, etc. can be cited. Among them, it is also preferable to use a developing roller that holds the developer on the surface.

[0156] The developer used in the developing device 11 may be a single-component developer containing only a toner or a two-component developer containing a toner and a carrier. The developer may be magnetic or non-magnetic. These developers are suitable for use with known developers.

[0157] - Cleaning device -

[0158] The cleaning device 13 uses a cleaning blade type device including a cleaning blade 131. In addition to the cleaning blade type, a brush cleaning method or a simultaneous development cleaning method may be used.

[0159] - Transfer device -

[0160] Examples of the transfer device 40 include a transfer charger known per se, such as a contact transfer charger using a belt, a roller, a film, a rubber blade, or the like, a scorotron transfer charger using corona discharge, or a corotron transfer charger.

[0161] -Intermediate transfer body-

[0162] A belt-shaped transfer body (intermediate transfer belt) made of polyimide, polyamideimide, polycarbonate, polyarylate, polyester, rubber, etc. imparted with semiconductivity is used as the intermediate transfer body 50. In addition, a drum-shaped transfer body may be used as the intermediate transfer body in addition to a belt-shaped transfer body.

[0163] Figure 4 FIG. 2 is a schematic diagram showing another example of the image forming apparatus according to the present embodiment.

[0164] Figure 4 The image forming apparatus 120 shown is a multi-color image forming apparatus of a tandem type equipped with four process cartridges 300. In the image forming apparatus 120, four process cartridges 300 are arranged side by side on the intermediate transfer body 50, respectively, so that a photosensitive body is used for each color. The image forming apparatus 120 has the same structure as the image forming apparatus 100 except that it is a tandem type.

[0165] [Example]

[0166] Hereinafter, embodiments of the present invention will be described in detail by way of examples, but the embodiments of the present invention are not limited to these examples.

[0167] In the following description, "part" and "%" are based on mass unless otherwise specified.

[0168] In the following description, unless otherwise specified, synthesis, production, treatment, measurement, etc. are performed at room temperature (25° C.±3° C.).

[0169] <Manufacturing of charging roller>

[0170] [Example 1]

[0171] -Preparation of supporting parts-

[0172] The cylindrical member made of SUM23L was subjected to electroless nickel plating with a thickness of 5 μm, and was further subjected to hexavalent chromic acid plating to obtain a support member with a diameter of 8 mm.

[0173] - Formation of adhesive layer -

[0174] Chlorinated polypropylene resin (maleic anhydride chlorinated polypropylene resin, Superchlon 930, Nippon Paper Chemicals Co., Ltd.): 100 parts

[0175] Epoxy resin (EP4000, ADEKA Corporation): 10 parts

[0176] Conductive agent: Carbon black (Ketjen Black EC, Ketjen Black International Co., Ltd.): 2.5 parts

[0177] Toluene or xylene: appropriate amount

[0178] The above materials were mixed and processed using a ball mill for 1 hour to obtain a resin composition. The resin composition was applied to the surface of the support member to form an adhesive layer with a thickness of 10 μm.

[0179] Epichlorohydrin rubber (Hydrin T3106, Japan Zeon Co., Ltd.): 100 parts

[0180] ·Electronic conductive agent: Carbon black (Asahi #60, Asahi Carbon Co., Ltd.): 6 parts

[0181] Ion conductive agent (BTEAC, Lion Corporation): 5 parts

[0182] Calcium carbonate (Whiton SB, Shiraishi Calcium Co., Ltd.): 20 parts

[0183] Vulcanizing agent: sulfur (VULNOC R, Ouchi Shinko Chemical Industry Co., Ltd.): 1 part

[0184] Vulcanization accelerator: stearic acid (NOF Corporation): 1 part

[0185] Vulcanization accelerator: zinc oxide: 1.5 parts

[0186] The above materials were mixed, kneaded using a tangential pressure kneader, and passed through a filter to obtain a rubber composition. The rubber composition was kneaded using an open roll and formed into a roll on the surface of the adhesive layer using a molding machine. Then, it was heated in a heating furnace at a temperature of 175°C for 70 minutes to obtain an elastic layer. The diameter of the elastic layer was 12 mm.

[0187] - Formation of the outer layer -

[0188] Binder resin: N-methoxymethylated nylon 1 (FR101, manufactured by Kyoshi Co., Ltd.): 100 parts

[0189] Conductive agent: carbon black (volume average particle size 43nm, MONAHRCH1000, Cabot): 15 parts

[0190] · Particles for forming unevenness: Polyamide particles (volume average particle size 10 μm, Orgasol 2001EXD Nat1, Arkema Co., Ltd.): 12 parts

[0191] The above materials were mixed, diluted with methanol, and dispersed for 60 minutes using a bead mill and glass beads with a diameter of 1.3 mm at a propeller speed of 2000 rpm. The obtained dispersion was applied to the surface of the elastic layer by a doctor blade method. Then, it was heated in a heating furnace at a temperature of 150°C for 30 minutes to form an outer layer with a thickness of 10 μm.

[0192] - Formation of protective layer -

[0193] Silicon dioxide-containing layer formation process

[0194] A charging roller having an outer layer is installed on a drum cartridge of an image forming device Apeos C7070 manufactured by Fujifilm Business Innovation Co., Ltd. At this time, the charging roller is installed without installing a cleaning roller of the charging roller. A developer containing a toner to which silica particles are added is filled into a developer of the image forming device. The image forming device is a type in which a charging member is in contact with a photoreceptor.

[0195] In an environment of temperature 10°C and relative humidity 15%, a color patch image with a total image density of 5% was outputted on 5,000 sheets of A4-size plain paper, in which many color patches were dispersed. By forming this image, a silicon dioxide-containing layer was formed on the surface of the outer layer of the charging roller. The charging roller having the silicon dioxide-containing layer was removed from the image forming apparatus.

[0196] Surface treatment process

[0197] The charging roller having the silicon dioxide layer was immersed in alkaline electrolytic water of pH 12 for 30 minutes to perform surface treatment. The charging roller was taken out from the alkaline electrolytic water and dried at room temperature for 24 hours to obtain a charging roller having a protective layer.

[0198] The thickness of the protective layer, the silicon dioxide content and the silicon element concentration, and the water contact angle of the outer peripheral surface were measured by the above-mentioned measurement methods.

[0199] [Example 2]

[0200] A charging roller was produced in the same manner as in Example 1 except that the immersion time in alkaline electrolytic water was changed to 3 minutes in the surface treatment step.

[0201] [Example 3]

[0202] A charging roller was produced in the same manner as in Example 1 except that the immersion time in alkaline electrolytic water was changed to 30 seconds in the surface treatment step.

[0203] [Example 4]

[0204] A charging roller was produced in the same manner as in Example 1 except that the number of patches output in the silicon dioxide-containing layer forming step was changed to 2,000 sheets and the immersion time in alkaline electrolytic water was changed to 30 seconds in the surface treatment step.

[0205] [Example 5]

[0206] A charging roller was produced in the same manner as in Example 1 except that the number of patches output in the silicon dioxide-containing layer forming step was changed to 10,000 sheets and the immersion time in alkaline electrolytic water was changed to 30 seconds in the surface treatment step.

[0207] [Comparative Example 1]

[0208] A charging roller was produced in the same manner as in Example 1, except that the surface treatment step was not performed.

[0209] [Comparative Example 2]

[0210] A charging roller was produced in the same manner as in Example 1 except that the alkaline electrolytic water was changed to ion-exchanged water in the surface treatment step.

[0211] [Comparative Example 3]

[0212] A charging roller was produced in the same manner as in Example 1 except that the number of patches output in the silicon dioxide-containing layer forming step was changed to 500 sheets and the immersion time in alkaline electrolytic water was changed to 30 seconds in the surface treatment step.

[0213] [Comparative Example 4]

[0214] A charging roller was produced in the same manner as in Example 1 except that the silicon dioxide-containing layer forming step was not performed.

[0215] [Example 6]

[0216] A charging roller was produced in the same manner as in Example 1 except that the silicon dioxide-containing layer forming step was changed to the following plasma CVD.

[0217] Silicon dioxide-containing layer formation process

[0218] A parallel plate type plasma CVD device was used. Using He as a carrier gas, TEOS (tetraethoxysilane) as a film-forming raw material was heated to 60°C to make it foam and introduced into the chamber. The flow rate of TEOS was controlled according to the bubbler pressure and the carrier gas flow rate, O2 was introduced as an oxidizing gas, and He was introduced as a diluent gas. With a high-frequency discharge of 13.56MHz, the film-forming temperature was set to 200°C and the reaction pressure was 1Torr. The flow rate was adjusted so that the film-forming speed was 100nm / min, and a silicon dioxide layer with a thickness of 5μm was formed.

[0219] <Charging unit performance evaluation>

[0220] The charging roller of each example was mounted on a drum cartridge of an image forming apparatus ApeosC7070 manufactured by Fujifilm Business Innovation Co., Ltd. This image forming apparatus is a type in which a charging member is in contact with a photoreceptor.

[0221] [Pollution resistance (1)]

[0222] In an environment of a temperature of 10° C. and a relative humidity of 15%, 100,000 sheets of a band-shaped image having an image density of 100% and a length of 320 mm×a width of 30 mm were outputted onto A3-size plain paper.

[0223] The surface of the charging roller was observed using a laser confocal microscope (OLS1100, manufactured by OLYMPAS) with a 1 μm square area in contact with the band-shaped toner image on the photoreceptor, and the contamination degree was classified as follows.

[0224] G0: Adherence is found on the surface of the charging roller, and the area ratio of the adhesion is 10% or less.

[0225] G0.5: Adhesions are found on the surface of the charging roller, and the area ratio of the adhesions is more than 10% and less than 20%.

[0226] G1: Adhesions are found on the surface of the charging roller, and the area ratio of the adhesions is more than 20% and less than 30%.

[0227] G2: Adhesions are found on the surface of the charging roller, and the area ratio of the adhesions is more than 30% and less than 40%.

[0228] G3: Adhesions are found on the surface of the charging roller, and the area ratio of the adhesions is more than 40% and less than 50%.

[0229] [Pollution resistance (2)]

[0230] After the evaluation of the stain resistance (1), 100,000 sheets of the same image were further output in the same environment. Thereafter (i.e., after a total of 200,000 sheets were output), the surface of the charging roller was observed by the same observation method as the evaluation of the stain resistance (1), and the degree of stain was classified as follows.

[0231] G0: Adherence is found on the surface of the charging roller, and the area ratio of the adhesion is 10% or less.

[0232] G0.5: Adhesions are found on the surface of the charging roller, and the area ratio of the adhesions is more than 10% and less than 20%.

[0233] G1: Adhesions are found on the surface of the charging roller, and the area ratio of the adhesions is more than 20% and less than 30%.

[0234] G2: Adhesions are found on the surface of the charging roller, and the area ratio of the adhesions is more than 30% and less than 40%.

[0235] G3: Adhesions are found on the surface of the charging roller, and the area ratio of the adhesions is more than 40% and less than 50%.

[0236] [crack]

[0237] After the evaluation of the contamination resistance (2), the surface of the charging roller was observed with a laser microscope (VK type) manufactured by Keyence Corporation at a magnification of 50. The number of cracks was counted in the entire area of ​​the outer peripheral surface with a width of 1 mm at both ends in the axial direction, and classified as follows. A crack with a width of 5 μm or more and a length of 50 μm or more was regarded as a crack and counted as "1".

[0238] G0: 0 cracks

[0239] G1: 1 to 4 cracks

[0240] G2: There are more than 5 cracks

[0241] [Table 1]

[0242]

[0243] (Note) (((1)))

[0245] A charging component comprising:

[0246] Support components;

[0247] an elastic layer disposed on the supporting member;

[0248] an outer layer disposed on the elastic layer; and

[0249] a protective layer, which is an outermost layer disposed on the outer layer,

[0250] The protective layer contains silicon dioxide and the silicon concentration is greater than 10 atomic %.

[0251] The water contact angle of the outer peripheral surface is 35 degrees or less. (((2)))

[0253] The charging member according to (((1))), wherein

[0254] The water contact angle of the outer peripheral surface is 25 degrees or less. (((3)))

[0256] The charging member according to (((1))) or (((2))), wherein

[0257] The silicon concentration of the protective layer is greater than 20 atomic % and less than 33 atomic %. (((4)))

[0259] The charging member according to any one of (((1))) to (((3))), wherein

[0260] The protective layer has a silicon dioxide content of 25 mass % or more and 100 mass % or less. (((5)))

[0262] The charging member according to any one of (((1))) to (((4))), wherein

[0263] The protective layer has a thickness of 1 μm or more and 10 μm or less. (((6)))

[0265] A method for manufacturing a charging member, which is a method for manufacturing the charging member described in any one of (((1))) to (((5))), comprising:

[0266] A step of preparing a member having, in sequence, a support member, an elastic layer, an outer layer, and a layer containing silicon dioxide; and

[0267] A step of bringing alkaline electrolyzed water into contact with the silicon dioxide-containing layer to impart hydroxyl groups to the surface of the silicon dioxide-containing layer to form a protective layer. (((7)))

[0269] A charging device comprising the charging member described in any one of (((1))) to (((5))). (((8)))

[0271] A processing box, comprising:

[0272] Photoreceptor;

[0273] a charging device having the charging member described in any one of (((1))) to (((5))) and contacting with a surface of the photoreceptor to charge the surface; and

[0274] an electrostatic latent image forming device that forms an electrostatic latent image on the charged surface of the photoreceptor,

[0275] The process cartridge is attachable to and detachable from the image forming apparatus. (((9)))

[0277] An image forming device comprising:

[0278] Photoreceptor;

[0279] A charging device comprising the charging member described in any one of (((1))) to (((5))) which contacts the surface of the photoreceptor to charge the surface;

[0280] an electrostatic latent image forming device that forms an electrostatic latent image on the charged surface of the photoreceptor;

[0281] a developing device for developing the electrostatic latent image formed on the surface of the photoreceptor using a developer containing a toner to form a toner image; and

[0282] A transfer device transfers the toner image to a surface of a recording medium.

[0283] According to (((1))), (((4))) or (((5))), a charging component is provided, which is less likely to be contaminated on the surface and less likely to crack in the outer layer even after long-term use, compared with a charging component whose silicon element concentration in the protective layer is less than 10 atomic% and whose water contact angle on the outer peripheral surface exceeds 35 degrees.

[0284] According to (((2))), there is provided a charging member whose surface is less likely to be contaminated even when used for a long period of time, compared with a charging member whose outer peripheral surface has a water contact angle exceeding 25 degrees.

[0285] According to (((3))), there is provided a charging member whose outer layer is less likely to be cracked even after long-term use, compared with a charging member having a protective layer with a silicon element concentration of less than 20 atomic %.

[0286] According to (((6))), there is provided a method for producing a charging member, wherein the surface of the charging member is less likely to be contaminated and the outer layer is less likely to crack even after long-term use, compared with a method in which alkaline electrolyzed water is not brought into contact with a layer containing silicon dioxide.

[0287] According to (((7))), a charging device is provided, which has a charging component, and the surface of the charging component is not easily contaminated and the outer layer is not easily cracked even after long-term use, compared with the case where the silicon concentration of the protective layer of the charging component is lower than 10 atomic% and the contact angle of water on the outer peripheral surface exceeds 35 degrees.

[0288] According to (((8))), a processing box is provided, which has a charging component, and the surface of the charging component is not easily contaminated and the outer layer is not easily cracked even after long-term use, compared with the case where the silicon concentration of the protective layer of the charging component is lower than 10 atomic% and the contact angle of water on the outer peripheral surface exceeds 35 degrees.

[0289] According to (((9))), an image forming device is provided, which has a charging component, the surface of which is less likely to be contaminated and the outer layer is less likely to crack even after long-term use, compared with a case where the silicon concentration of the protective layer of the charging component is lower than 10 atomic % and the contact angle of water on the outer peripheral surface exceeds 35 degrees.

Claims

1. A charging component, characterized in that: have: Support components; an elastic layer, the elastic layer being disposed on the supporting member; an outer layer disposed on the elastic layer; and a protective layer, the protective layer being the outermost layer disposed on the outer layer, The protective layer contains silicon dioxide and the silicon concentration is greater than 10 atomic %. The water contact angle of the outer peripheral surface is 35 degrees or less.

2. The charging member according to claim 1, wherein The water contact angle of the outer peripheral surface is 25 degrees or less.

3. The charging member according to claim 1 or 2, wherein The silicon concentration of the protective layer is greater than 20 atomic % and less than 33 atomic %.

4. The charging member according to any one of claims 1 to 3, wherein The protective layer has a silicon dioxide content of 25 mass % or more and 100 mass % or less.

5. The charging member according to any one of claims 1 to 4, wherein The protective layer has a thickness of 1 μm or more and 10 μm or less.

6. A method for producing a charging member, which is a method for producing the charging member according to any one of claims 1 to 5, characterized in that: include: A step of preparing a member having, in order, a support member, an elastic layer, an outer layer, and a layer containing silicon dioxide; as well as A step of bringing alkaline electrolyzed water into contact with the silicon dioxide-containing layer to impart hydroxyl groups to the surface of the silicon dioxide-containing layer to form a protective layer. 7 . A charging device comprising the charging member according to claim 1 .

8. A processing box, characterized in that: have: Photoreceptor; A charging device comprising a charging member according to any one of claims 1 to 5, wherein the charging member contacts the surface of the photoreceptor to charge the photoreceptor; as well as an electrostatic latent image forming device for forming an electrostatic latent image on the charged surface of the photoreceptor, The process cartridge is attachable to and detachable from the image forming apparatus.

9. An image forming device, characterized in that: have: Photoreceptor; A charging device comprising a charging member according to any one of claims 1 to 5, wherein the charging member contacts the surface of the photoreceptor to charge the photoreceptor; an electrostatic latent image forming device for forming an electrostatic latent image on the charged surface of the photoreceptor; a developing device that develops the electrostatic latent image formed on the surface of the photoreceptor using a developer containing a toner to form a toner image; as well as A transfer device transfers the toner image to a surface of a recording medium.

Images