Conductive roller, transfer device, process cartridge, and image forming apparatus

Abstract

The present application relates to a conductive roller, a transfer device, a process cartridge, and an image forming apparatus. A conductive roller has a support member, an elastic layer disposed on an outer circumferential surface of the support member, a surface layer disposed on an outer circumferential surface of the elastic layer, and an intermediate layer disposed between the elastic layer and the surface layer, and a Poisson's ratio is 0.40 or less.

Description

Technical Field

[0001] This invention relates to a conductive roller, a transfer device, a processing box, and an image forming apparatus. Background Technology

[0002] Patent Document 1 discloses "a transfer roller comprising: a conductive support; a conductive elastic layer disposed on the conductive support; and a conductive resin layer disposed on the conductive elastic layer, comprising a resin material and a conductive agent, the conductive resin layer having a first region and a second region forming the outermost surface, the second region being disposed between the first region and the conductive elastic layer in contact with the conductive elastic layer, and having a lower surface resistivity than the first region, the transfer roller forming an engagement portion in an inclined manner with an axial bite amount, and when a recording medium is inserted into the engagement portion, the difference between the conveying amount at the 0.5 mm bite amount position and the conveying amount at the 1.3 mm bite amount position is 1.5 mm or more / 400 mm."

[0003] Patent document 2 proposes "a colorant supply roller for an electronic photographic device, which has a shaft and a roller-shaped polyurethane foam formed on the outer periphery of the shaft. The colorant supply roller is characterized in that the storage modulus of the polyurethane foam is 100 kPa or more, and has a connected surface unit and a central unit. The average unit diameter of the central unit is 200 to 1000 μm. The relationship between the width of the interlocking part when the curved surface is pressed and the width of the interlocking part when the flat surface is pressed satisfies the following equation (1): Width of the interlocking part when the curved surface is pressed ≥ (width of the interlocking part when the flat surface is pressed × 0.65)……(1)".

[0004] Patent Document 1: Japanese Patent Application Publication No. 2014-126602

[0005] Patent Document 2: Japanese Patent Application Publication No. 2014-071147 Summary of the Invention

[0006] The objective of this invention is to provide a conductive roller comprising: a support member; an elastic layer disposed on the outer peripheral surface of the support member; a surface layer disposed on the outer peripheral surface of the elastic layer; and an intermediate layer disposed between the elastic layer and the surface layer, wherein, compared to cases where the Poisson's ratio of the intermediate layer exceeds 0.40, it is easier to improve the parallelism of the image transferred onto the recording medium.

[0007] The specific means used to solve the problem include the following methods.

[0008] <1> A conductive roller, comprising:

[0009] Support components;

[0010] An elastic layer is disposed on the outer peripheral surface of the support member;

[0011] A surface layer, disposed on the outer peripheral surface of the elastic layer; and

[0012] An intermediate layer, disposed between the elastic layer and the surface layer, has a Poisson's ratio of 0.40 or less.

[0013] <2> The conductive roller according to <1>, wherein,

[0014] The thickness Td of the elastic layer, the thickness Tm of the intermediate layer, and the thickness Ts of the surface layer satisfy the relationship Td > Tm > Ts.

[0015] <3> The conductive roller according to <2>, wherein,

[0016] The thickness Td of the elastic layer, the thickness Tm of the intermediate layer, and the thickness Ts of the surface layer satisfy the relationship 0.07≤Tm / (Td+Tm+Ts)≤0.43.

[0017] <4> The conductive roller according to <2> or <3>, wherein,

[0018] The thickness Tm of the intermediate layer is greater than 0.5 mm and less than 4 mm.

[0019] <5> The conductive roller according to any one of <2> to <4>, wherein,

[0020] The thickness Ts of the surface layer is greater than 10 μm and less than 50 μm.

[0021] <6> The conductive roller according to any one of <1> to <5>, wherein,

[0022] The Young's modulus Ys of the surface layer is above 10 MPa and below 400 MPa.

[0023] <7> The conductive roller according to any one of <1> to <6>, wherein,

[0024] The elastic layer comprises a cylindrical elastic foam and a conductive covering layer that covers the exposed surface of the elastic foam.

[0025] <8> The conductive roller according to <7>, wherein,

[0026] The elastic foam has a continuous bubble structure.

[0027] <9> The conductive roller according to <7> or <8>, wherein,

[0028] The density of the elastic foam is 50 kg / m³.3 Above and 90kg / m 3 the following.

[0029] <10> A transfer device comprising any one of <1> to <9> conductive rollers.

[0030] <11> A processing box having an image holding body and the transfer device described in <10>, and being detachable from an image forming apparatus.

[0031] <12> An image forming apparatus comprising:

[0032] Image holding volume;

[0033] A charging device that charges the surface of the image holder.

[0034] An electrostatic latent image forming apparatus forms an electrostatic latent image on the surface of the charged image holder;

[0035] A developing apparatus that develops an electrostatic latent image formed on the surface of the image holder using a developer containing a toner to form a toner image; and

[0036] The transfer apparatus described in <10> transfers the toner image onto the surface of the recording medium.

[0037] Invention Effects

[0038] According to <1> of the present invention, a conductive roller is provided, comprising: a support member; an elastic layer disposed on the outer peripheral surface of the support member; a surface layer disposed on the outer peripheral surface of the elastic layer; and an intermediate layer disposed between the elastic layer and the surface layer, wherein, compared with the case where the Poisson ratio of the intermediate layer exceeds 0.40, it is easier to improve the parallelism of the image transferred onto the recording medium.

[0039] According to <2> of the present invention, a conductive roller is provided that can easily improve the parallelism of an image transferred onto a recording medium compared to cases where the relationship Td>Tm>Ts is not satisfied.

[0040] According to <3> of the present invention, a conductive roller is provided that can easily improve the parallelism of an image transferred onto a recording medium compared to the case where 0.07>Tm / (Td+Tm+Ts).

[0041] According to <4> of the present invention, a conductive roller is provided that easily improves the parallelism of the image transferred onto the recording medium compared to cases where the thickness Tm of the intermediate layer is less than 0.5 mm or more than 4 mm.

[0042] According to <5> of the present invention, a conductive roller is provided that exhibits superior cleanliness compared to cases where the thickness Ts of the surface layer is less than 10 μm or more than 50 μm.

[0043] According to <6> of the present invention, a conductive roller is provided that exhibits superior cleanliness compared to cases where the Young's modulus Ys of the surface layer is less than 10 MPa or more than 400 MPa.

[0044] According to <7> of the present invention, a conductive roller is provided, which, compared with the case where the elastic layer is composed of a cylindrical elastic foam made of conductive agent compound, can easily improve the parallelism of the image transferred onto the recording medium.

[0045] According to <8> of the present invention, a conductive roller is provided, which, compared with the case where the elastic foam has an independent bubble structure, can easily improve the parallelism of the image transferred onto the recording medium.

[0046] According to <9> of the present invention, a conductive roller is provided, the density of which is less than 50 kg / m³ of elastic foam. 3 or more than 90kg / m 3 Compared to the following situations, it is easier to improve the parallelism of the image transferred onto the recording media.

[0047] According to <10>, <11> or <12> of the present invention, a transfer apparatus, processing cartridge or image forming apparatus is provided that, in a conductive roller having a support member, an elastic layer disposed on the outer peripheral surface of the support member, a surface layer disposed on the outer peripheral surface of the elastic layer, and an intermediate layer disposed between the elastic layer and the surface layer, the parallelism of the image transferred onto the recording medium is easily improved compared to cases where the Poisson's ratio of the intermediate layer exceeds 0.40. Attached Figure Description

[0048] The embodiments of the present invention will be described in detail with reference to the following figures.

[0049] Figure 1 It is a schematic diagram used to illustrate the parallelism of an image transferred onto a recording medium;

[0050] Figure 2 This is a schematic perspective view showing an example of the conductive roller according to this embodiment;

[0051] Figure 3 This is a schematic cross-sectional view showing an example of the conductive roller according to this embodiment. Figure 2 AA section view;

[0052] Figure 4 This is a schematic structural diagram illustrating an example of the image forming apparatus according to this embodiment;

[0053] Figure 5 This is a schematic structural diagram showing another example of the image forming apparatus according to this embodiment.

[0054] Symbol Explanation

[0055] 100-Conductive roller, 110-Support component, 122-Elastic layer, 124-Intermediate layer, 126-Surface layer, 200-Image forming apparatus, 206-Exposure apparatus, 207-Photoreceptor, 208-Electrified roller, 209-Power supply, 211-Developing apparatus, 212-Transfer roller, 213-Cleaning apparatus, 214-Electrification apparatus, 215-Fixing apparatus, 500-Recording paper, 1Y, 1M, 1C, 1K-Photoreceptor, 2Y, 2M, 2C, 2K-Electrified roller, 3-Exposure The apparatus includes: 3Y, 3M, 3C, 3K laser beams; 4Y, 4M, 4C, 4K developing unit; 5Y, 5M, 5C, 5K primary transfer rollers; 6Y, 6M, 6C, 6K photoreceptor cleaning unit; 8Y, 8M, 8C, 8K toner cartridges; 10Y, 10M, 10C, 10K image forming unit; 20 intermediate transfer belt; 22 drive roller; 24 support roller; 26 secondary transfer roller; 28 fixing unit; 30 intermediate transfer belt cleaning unit; and P recording paper. Detailed Implementation

[0056] The embodiments of the present invention will be described below. These descriptions and examples illustrate the embodiments but do not limit the scope of the embodiments.

[0057] In this invention, the numerical range indicated by “~” represents the range included by taking the values ​​before and after “~” as the minimum and maximum values, respectively.

[0058] In the numerical ranges described in stages in this invention, the upper or lower limit value described in one numerical range can be replaced with the upper or lower limit value of other numerical ranges described in stages. Furthermore, the upper or lower limit value of the numerical range described in this invention can also be replaced with the values ​​shown in the embodiments.

[0059] In this invention, the term "process" includes not only independent processes, but also processes that achieve the intended purpose, even if they cannot be clearly distinguished from other processes.

[0060] In this invention, embodiments are described with reference to the accompanying drawings, but the structure of these embodiments is not limited to the structure shown in the drawings. Furthermore, the sizes of the components in the figures are conceptual sizes, and the relative sizes between the components are not limited thereto.

[0061] In this invention, each component may comprise a plurality of corresponding substances. In this invention, when referring to the amount of each component in a composition, unless otherwise stated, the amount refers to the total amount of such substances present in the composition, where a plurality of substances corresponding to each component are present in the composition.

[0062] <Conductive Roller>

[0063] The conductive roller according to this embodiment has: a support member; an elastic layer disposed on the outer peripheral surface of the support member; a surface layer disposed on the outer peripheral surface of the elastic layer; and an intermediate layer disposed between the elastic layer and the surface layer, having a Poisson's ratio of 0.40 or less.

[0064] The conductive roller described in this embodiment is not particularly limited in its application as long as it is a conductive roller that presses its outer peripheral surface onto an opposing roller to form an insertion portion for inserting a recording medium, and is used to transfer an image onto the recording medium through the insertion portion. That is, the conductive roller described in this embodiment is used to press its outer peripheral surface onto an opposing roller, using the pressed area as an insertion portion to insert the recording medium, and to transfer an image onto the recording medium through this insertion portion.

[0065] The conductive roller described in this embodiment is preferably used, for example, as a transfer roller in an electrophotographic image forming apparatus. However, the applications of the conductive roller described in this embodiment are not limited to the above-described applications; examples include peeling rollers, support rollers, and tension rollers.

[0066] The conductive roller described in this embodiment, based on the above structure, easily improves the parallelism of the image transferred onto the recording medium. The reason for this is speculated to be as follows.

[0067] The outer peripheral surface of the conductive roller is pressed onto the opposing roller to form an insertion part that allows the recording medium to pass through. When an image is transferred to the recording medium through the insertion part, the parallelism of the image transferred to the recording medium may be reduced.

[0068] Here, the parallelism of the transferred image refers to the image's parallelism relative to the transport direction of the recording medium P in the insertion section. Figure 1 (a) and Figure 1 The direction of the arrow Y in (b) is orthogonal to the direction of the arrow. Figure 1 (a) and Figure 1 The degree of parallelism of the arrow (X direction) in (b). Specifically, as... Figure 1 As shown in (a), for example, in the case where it is desired to form a rectangular image G1 on a recording medium P consisting of sides parallel to each side of the recording medium P, the parallelism of the transferred image is determined by the image G2 actually transferred to the recording medium P, such as... Figure 1 (b) shows the arrow X direction on one side ( Figure 1The length L of the line image marked as Front Front With the other end ( Figure 1 The length L of the line image marked Rear Rear The difference ΔL (=L) Front -L Rear )express.

[0069] As a method for correcting the aforementioned ΔL, the following method can be used: adjust the amount of pressure of the conductive roller toward the opposing roller at both ends of the axial direction of the conductive roller, so as to create a difference in the amount of recording medium being transported in a direction orthogonal to the transport direction of the recording medium.

[0070] Therefore, in the conductive roller, the Poisson's ratio of the intermediate layer disposed between the elastic layer and the surface layer is set to 0.40 or less to facilitate deformation. Because the intermediate layer is easily deformable, the amount of pressure from the conductive roller onto the opposing roller can be increased, and adjustments can be easily made at both ends of the conductive roller's axial direction.

[0071] Therefore, it is speculated that the conductive roller involved in this embodiment can easily improve the parallelism of the image transferred onto the recording medium.

[0072] In the conductive roller of this embodiment, from the viewpoint of easily improving the parallelism of the image transferred to the recording medium, the Poisson's ratio of the intermediate layer is preferably 0.4 or less, and more preferably 0.38 or less.

[0073] However, if the Poisson's ratio of the intermediate layer is too low, the compression deformation of the intermediate layer will be large. Therefore, from the viewpoint of effectively reducing the paper passage speed control effect, it is preferable to be 0.3 or higher.

[0074] Here, Poisson's ratio is determined as follows.

[0075] Analysis of the intermediate layer composition based on the target conductive roller.

[0076] Using the same combination as the analyzed intermediate layer, prepare strips with a width of 10 mm, a thickness of 1 mm, and a mark spacing of 40 mm, and mount them on a tensile testing machine. Measure the strip width 20 mm from the bottom of the mark using a laser. Calculate the transverse strain εb based on the strip width when stretched by 30% at a tensile speed of 10 mm / min, and determine Poisson's ratio using εb / εL based on the longitudinal strain εL calculated in the tensile direction.

[0077] The conductive roller according to this embodiment will be described with reference to the accompanying drawings.

[0078] Figure 2 This is a schematic perspective view showing an example of the conductive roller according to this embodiment. Figure 3 yes Figure 2 The AA sectional view is to Figure 2The diagram shows a radially cut cross-sectional view of the conductive roller.

[0079] like Figure 2 As shown, the conductive roller 100 is a roller component comprising a cylindrical support member 110 and a layered structure 120. The layered structure 120 is disposed on the outer peripheral surface of the support member 110 and includes an elastic layer, an intermediate layer, and a surface layer. Furthermore, as... Figure 3 As shown, the conductive roller 100 has a layer structure comprising an elastic layer 122 disposed on the outer peripheral surface of the cylindrical support member 110, an intermediate layer 124 disposed on the outer peripheral surface of the elastic layer 122, and a surface layer 126 disposed on the outer peripheral surface of the intermediate layer 124.

[0080] The conductive roller involved in this embodiment is not limited to... Figure 2 and Figure 3 The structure shown may, for example, also have an adhesive layer between the support member 110 and the elastic layer 122, between the elastic layer 122 and the intermediate layer 124, and between the intermediate layer 124 and the surface layer 126.

[0081] The materials of each layer constituting the conductive roller according to this embodiment will be described below.

[0082] [Supporting Components]

[0083] In the conductive roller described in this embodiment, the support member can be any member that functions as a support member for the conductive roller.

[0084] The supporting component can be a hollow component (i.e., a cylindrical component) or a solid component (i.e., a cylindrical component).

[0085] Furthermore, when an electric field is formed between the conductive roller and the opposing roller, the support member is preferably a conductive support member, for example.

[0086] Examples of conductive support components include metal components such as iron (free-cutting steel, etc.), copper, brass, stainless steel, aluminum, and nickel; resin or ceramic components with electroplated outer surfaces; and resin or ceramic components containing conductive agents.

[0087] The outer diameter of the support component can be determined based on the intended use of the conductive roller.

[0088] For example, if the conductive roller involved in this embodiment is a secondary transfer roller, then as an example, the outer diameter of the support member can be 3 mm or more and 30 mm or less.

[0089] [Elastic layer]

[0090] The elastic layer may include, for example, an elastic material, a conductive agent, and, if necessary, other additives.

[0091] Examples of elastic materials include isoprene rubber, chloroprene rubber, epichlorohydrin rubber, butyl rubber, polyurethane, silicone rubber, fluororubber, styrene-butadiene rubber, butadiene rubber, nitrile rubber, ethylene propylene rubber, epichlorohydrin-ethylene oxide copolymer rubber, epichlorohydrin-ethylene oxide-allyl glycidyl ether terpolymer rubber, ethylene-propylene-diene terpolymer rubber (EPDM), acrylonitrile-butadiene copolymer rubber (NBR), natural rubber, and rubbers made by mixing these materials.

[0092] Examples of conductive agents include electronic conductive agents and ionic conductive agents. Examples of electronic conductive agents include carbon black such as Ketjen black and acetylene black; thermally decomposed carbon and graphite; various conductive metals or alloys such as aluminum, copper, nickel, and stainless steel; various conductive metal oxides such as tin oxide, indium oxide, titanium oxide, tin oxide-antimony oxide solid solutions, and tin oxide-indium oxide solid solutions; substances whose surfaces have been treated to make insulating materials conductive; and powders. Examples of ionic conductive agents include perchlorates and chlorates such as tetraethylammonium and lauryltrimethylammonium; and perchlorates and chlorates of alkali metals and alkaline earth metals such as lithium and magnesium.

[0093] These conductive agents can be used alone or in combination of two or more.

[0094] Other additives include known materials that can be added to elastomers, such as softeners, plasticizers, curing agents, vulcanizing agents, vulcanization accelerators, antioxidants, surfactants, coupling agents, and fillers (silica, calcium carbonate, etc.).

[0095] The elastic layer preferably comprises, for example, a cylindrical elastic foam and a conductive covering layer that covers the exposed surface of the elastic foam.

[0096] The elastic layer in this structure is made conductive by a conductive coating layer, resulting in a softer elastic layer compared to including a conductive agent in the elastic foam. Therefore, the elastic layer easily deforms when the conductive roller is pressed into the opposing roller, making it easier to create a conductive roller that improves the parallelism of the image transferred onto the recording medium.

[0097] (Elastic foam)

[0098] The elastic foam that makes up the elastic layer is a foam containing elastic material (also known as rubber material).

[0099] The elastic material is applicable as an elastic material.

[0100] Examples of foaming agents used to obtain elastic foams include water; azo compounds such as azodicarbonamide, azobisisobutyronitrile, and diazoaminobenzene; benzenesulfonyl hydrazides such as benzenesulfonyl hydrazide, 4,4'-oxobisbenzenesulfonyl hydrazide, and toluenesulfonyl hydrazide; bicarbonates such as sodium bicarbonate that produce carbon dioxide gas through thermal decomposition; mixtures of NaNO2 and NH4Cl that produce nitrogen gas; peroxides that produce oxygen gas; and so on.

[0101] To obtain elastic foam, foaming aids, defoamers, catalysts, etc., can be used as needed.

[0102] From the perspective of controlling the conductivity of the elastic layer, elastic foams can contain conductive agents.

[0103] Conductive agents contained in elastic foams can include electronic conductive agents and ionic conductive agents.

[0104] Furthermore, from the viewpoint of designing a conductive roller that easily improves the parallelism of the image transferred to the recording medium, the content of conductive agent (especially in the case of electronic conductive agent) in the elastic foam is, for example, 1% by mass or less relative to the total mass of the elastic foam, preferably 0.5% by mass or less, and more preferably 0% by mass or less.

[0105] That is, the less electronic conductive agent in the elastic foam, the better. It is assumed that even if the elastic foam contains conductive particles, the content of electronic conductive agent needs to be less than 1% by mass relative to the total mass of the elastic foam.

[0106] Furthermore, if the elastic foam contains the aforementioned particulate materials such as electronically conductive agents and fillers, the hardness of the elastic layer increases, and the peelability of the medium tends to decrease. Therefore, it is preferable to have as few particulate materials as possible in the elastic foam. Even if the elastic foam contains particulate materials, the total content of particulate materials is preferably less than 1% by mass relative to the total mass of the elastic foam.

[0107] From the viewpoint of the formability of the conductive coating layer, and from the viewpoint of the conductive roller being designed to easily improve the parallelism of the image transferred onto the recording medium, the bubble structure in the elastic foam is more preferably a continuous bubble structure, for example.

[0108] Here, a continuous bubble structure refers to a structure in which adjacent units (i.e., bubbles) are connected, and a portion of the connected units is exposed (open) on the surface.

[0109] Furthermore, in elastic foams, a lower percentage of independent bubbles is preferred, for example, a percentage of independent bubbles is preferably 50% or less (more preferably 30% or less).

[0110] From the viewpoint of the formation of the conductive coating layer and the viewpoint of the conductive roller designed to easily improve the parallelism of the image transferred to the recording medium, the unit diameter (also known as the bubble diameter) of the elastic foam is preferably 50 μm or more and 1000 μm or less, more preferably 100 μm or more and 800 μm or less, and even more preferably 150 μm or more and 600 μm or less.

[0111] From the viewpoint of the formation of the conductive coating layer, and from the viewpoint of the conductive roller designed to easily improve the parallelism of the image transferred onto the recording medium, the density (also known as the bubble ratio) of the elastic foam is preferably, for example, 50 kg / m³. 3 Above and 90kg / m 3 The following is more preferably 55 kg / m 3 Above and 85kg / m 3 The following is a further preferred value: 60 kg / m 3 Above and 80kg / m 3 the following.

[0112] Here, the unit diameter (bubble diameter), foaming rate (bubble rate), and independent bubble rate in the elastic foam are measured as follows.

[0113] First, a cross-section along the thickness direction of the elastic layer (the elastic foam within the elastic layer) is created using a razor. Four cross-sections are created in the circumferential direction at 90° intervals, parallel to the axis of the conductive roller.

[0114] Images were acquired by photographing the axial central portion of the cross-section using a laser microscope (EYENCE CORPORATION., VK-X200). The images were analyzed using image analysis software (Media Cybernetics, Inc., Image-Pro Plus), and the maximum diameter and area of ​​the cells (bubbles) were determined.

[0115] Furthermore, when the elastic foam has a continuous bubble structure, the continuity of the unit (bubble) is inferred based on the shape of the continuous bubbles. The continuous (connected) units are then simulated and separated to determine the maximum diameter of the separated units. That is, if the continuous bubbles are inferred to be, for example, in the shape of 5 continuous (connected) bubbles, the 5 units are simulated and separated into 5 units, and the maximum diameter of the 5 separated units is measured.

[0116] The element diameter is set to the arithmetic mean of the maximum diameters of 100 randomly selected elements in the analyzed profile image, and the arithmetic mean of the four profiles is calculated based on the obtained values.

[0117] The foaming rate is calculated by (total area of ​​cells in the analyzed profile image) / (total area of ​​the analyzed profile image) × 100.

[0118] The independent bubble ratio is calculated by (total area of ​​independent bubbles in the analyzed profile image) / (total area of ​​bubbles in the analyzed profile image) × 100.

[0119] Here, an independent bubble is defined as a bubble that is completely surrounded by the wall in the cross-sectional image.

[0120] Furthermore, the density of the elastic foam was determined as follows.

[0121] An elastic layer (an elastic foam within the elastic layer) is used, and a cube is constructed using a razor. The cube is made as large as possible to accurately determine the density. Next, the length, width, and height of the cube are measured, the volume is calculated, the weight is measured, and the density is determined from the weight / volume.

[0122] (Young's modulus of the elastic layer)

[0123] In the conductive roller of this embodiment, from the viewpoint of making it a conductive roller that easily improves the parallelism of the image transferred to the recording medium, the Young's modulus of the elastic layer is preferably 50 kPa or more and 500 kPa or less, more preferably 60 kPa or more and 300 kPa or less, and even more preferably 80 kPa or more and 150 kPa or less.

[0124] The aforementioned Young's modulus can be easily achieved by reducing the content of particulate matter (such as electronically conductive agents, fillers, etc.) in the elastic foam.

[0125] Young's modulus was determined as follows.

[0126] The method for determining Young's modulus is basically based on ISO 527.

[0127] The combination of elastic layers is analyzed from the target conductive roller.

[0128] Using the same composition as the analyzed elastic layer, dumbbell-shaped tensile specimens with a marking spacing of 50 mm and a thickness of 5 mm were made into single-layer sheets. The stress (σ)-strain (ε) curves at a tensile speed of 5 mm / min were obtained using a benchtop precision universal testing machine (AGS-X; manufactured by SHIMADZU CORPORATION). The stress at strains of 0.05% to 0.25% was measured, and the Young's modulus was calculated from Δσ / Δε.

[0129] -Formation of elastic foam-

[0130] There are no particular restrictions on the method of forming cylindrical elastic foams, and known methods can be used.

[0131] For example, the following methods can be cited: preparing a composition comprising an elastic material, a foaming agent, and other components (such as a vulcanizing agent, etc.) as needed; after extruding the composition into a cylindrical shape, heating the molded article to vulcanize and foam it; and cutting a large foam into a cylindrical shape.

[0132] Furthermore, a cylindrical elastic foam can also be obtained by forming a central hole for inserting a support component after forming a cylindrical elastic foam.

[0133] In addition, after obtaining the cylindrical elastic foam, the shape can be adjusted as needed, and post-processing such as surface grinding can also be performed.

[0134] (Conductive coating)

[0135] The conductive capping layer constituting the elastic layer is a conductive layer that covers the exposed surface of the elastic foam (i.e., the surface in contact with the atmosphere of the elastic foam, and includes the inner circumferential surface, outer circumferential surface and unit wall surface of the cylindrical elastic foam).

[0136] The exposed surface of the elastic foam can be completely covered by a conductive coating layer, or it can be partially covered.

[0137] A conductive coating layer can be formed using a treatment solution containing conductive agents and resins.

[0138] Here, as a conductive agent for the treatment liquid, examples include electronic conductive agents or ionic conductive agents, with electronic conductive agents being preferred.

[0139] The treatment solution may contain one or two conductive agents.

[0140] Here, as an example of an electronically conductive agent, the preferred method is the same as that used in elastic foams.

[0141] The resin used for the treatment liquid is not particularly limited if it can form a covering layer on the exposed surface of the elastic foam; examples include acrylic resins, urethane resins, fluoropolymers, and silicone resins. These resins are preferably used as latex, for example.

[0142] Examples of latex, besides the resins mentioned above, include natural rubber latex, butadiene rubber latex, acrylonitrile-butadiene rubber latex, acrylic rubber latex, polyurethane rubber latex, fluororubber latex, and silicone rubber latex.

[0143] The processing liquid is preferably a mixture containing a conductive agent, a resin, and water, i.e., an aqueous dispersion containing a conductive agent and a resin.

[0144] The concentrations of conductive agent and resin in the treatment solution can be determined based on the formability of the conductive coating layer and the required resistance value of the elastic layer.

[0145] -Formation of a conductive coating-

[0146] An elastic foam is given a treatment liquid and then dried by heating to form a conductive coating layer.

[0147] Methods for applying a treatment liquid to elastic foams include coating the elastic foam with the treatment liquid by spraying or immersing the elastic foam in the treatment liquid.

[0148] Through these methods, the treatment solution is impregnated onto the surface of the elastic foam and into the interior of the bubbles. Then, the elastic foam with the treatment solution attached is dried by heating or other means, thereby forming a conductive coating layer.

[0149] As a conductive capping layer, for example, the capping layer and its formation method described in Japanese Patent Application Publication No. 2009-244824 can be applied.

[0150] As described above, the elastic layer in the conductive roller according to this embodiment is formed by forming a conductive covering layer on the exposed surface of the elastic foam.

[0151] (Volume resistivity of the elastic layer)

[0152] In the conductive roller of this embodiment, the volume resistivity of the elastic layer when a voltage of 10V is applied is preferably 105Ω or less, more preferably 101Ω or more and 105Ω or less, and even more preferably 102Ω or more and 104Ω or less.

[0153] Here, the volume resistivity of the elastic layer is measured as follows.

[0154] First, an elastic layer, which is the object of measurement, is formed on the outer periphery of the conductive support member, and the volume resistivity of the elastic layer is measured using the resulting roller member. Furthermore, when the conductive roller according to this embodiment has a conductive support member, the roller member from which the surface layer has been peeled off can be measured.

[0155] A 500g load is applied to each end of the roller assembly, and the roller assembly is placed on a metal plate such as a copper plate. A voltage of 10V (in the case of an elastic layer) is applied between the conductive support of the roller assembly and the metal plate using a microcurrent meter (R8320 manufactured by ADVANTEST CORPORATION). The current value I (A) is read after 5 seconds and calculated by the following formula.

[0156] Formula: Volume resistivity Rv (Ω) = V / I

[0157] In addition, the measurements were conducted at a temperature of 22°C and a humidity of 55%RH.

[0158] (Thickness of the elastic layer)

[0159] In the conductive roller described in this embodiment, the thickness of the elastic layer can be determined according to the application of the conductive roller.

[0160] For example, if the conductive roller involved in this embodiment is a secondary transfer roller, then as an example, the thickness of the elastic layer can be 1 mm or more and 10 mm or less.

[0161] [Middle Layer]

[0162] The intermediate layer is a layer disposed between the elastic layer and the surface layer.

[0163] The intermediate layer comprises a soft adhesive material with a Poisson's ratio within the aforementioned range.

[0164] As an adhesive material, there are no particular limitations if the Poisson's ratio is set within the aforementioned range, and examples include resins and elastic materials that can form the intermediate layer. Examples of resins used for the intermediate layer include urethane resins, acrylic resins, epoxy resins, and silicone resins. Furthermore, the same elastic material used in the elastic layer is used as the elastic material included in the intermediate layer.

[0165] From the viewpoint of setting the Poisson's ratio within the above-mentioned range, urethane resin is preferred as an adhesive material, for example.

[0166] The intermediate layer is a layer that helps adjust the resistance of the conductive roller, and its volume resistivity when a voltage of 100V is applied is preferably, for example, 10. 4 Ω or higher and 10 9 Ω or less (more preferably 10) 6 Ω or higher and 10 9 (below Ω).

[0167] In addition, the volume resistivity of the intermediate layer was measured using the same method as that of the elastic layer.

[0168] The intermediate layer preferably contains a conductive agent to achieve the aforementioned volume resistivity value.

[0169] Both electronic and ionic conductive agents are used as conductive agents, but from the viewpoint of improving charge maintenance, ionic conductive agents are preferred, for example.

[0170] That is, the intermediate layer preferably contains, for example, an ionic conductive agent. Examples of ionic conductive agents contained in the intermediate layer include the same ionic conductive agents contained in the elastic foam, and preferably in the same manner.

[0171] Ionic conductive agents can be used alone or in combination of two or more.

[0172] Furthermore, the ionic conductive agent used for the intermediate layer can also be a polymer material with ionic conductivity, such as epichlorohydrin rubber, epichlorohydrin-ethylene oxide copolymer rubber, epichlorohydrin-ethylene oxide-allyl glycidyl ether ternary copolymer rubber, etc.

[0173] Furthermore, the ionic conductive agent used in the intermediate layer can be a compound in which the ionic conductive agent is bonded to the end of a polymer material such as a resin.

[0174] The content of the ionic conductive agent only needs to be within the range that can achieve the above-mentioned volume resistivity value.

[0175] Furthermore, the content of the ionic conductive agent is preferably 0.1 parts by mass or more and 5.0 parts by mass or less relative to 100 parts by mass of the adhesive material, and more preferably 0.5 parts by mass or more and 3.0 parts by mass or less.

[0176] The intermediate layer may contain other additives depending on the required physical properties of the intermediate layer.

[0177] (Thickness of the intermediate layer)

[0178] In the conductive roller described in this embodiment, the thickness of the intermediate layer can be determined according to the application of the conductive roller.

[0179] However, from the viewpoint of designing a conductive roller that easily improves the parallelism of the image transferred to the recording medium, the thickness of the intermediate layer is preferably adjusted, for example, to such that the thickness Td of the elastic layer, the thickness Tm of the intermediate layer, and the thickness Ts of the surface layer satisfy the relationship Td > Tm > Ts.

[0180] Specifically, the thickness of the intermediate layer is preferably adjusted such that the thickness of the elastic layer Td, the thickness of the intermediate layer Tm, and the thickness of the surface layer Ts satisfy the relationship 0.07≤Tm / (Td+Tm+Ts)≤0.43 (especially, 0.08≤Tm / (Td+Tm+Ts)≤0.3).

[0181] More specifically, the thickness of the intermediate layer is preferably 0.5 mm or more and 5 mm or less, more preferably 0.5 mm or more and 3 mm or less.

[0182] The method of forming the intermediate layer is not particularly limited. For example, a method can be given by coating an intermediate layer forming liquid onto an elastic layer and drying the resulting coating film.

[0183] [Surface layer]

[0184] The surface layer is a layer disposed on the outer peripheral surface of the intermediate layer, and is the outermost layer that constitutes the conductive roller.

[0185] Since the surface layer is in contact with the medium, it is preferably mold-resistant, for example.

[0186] The surface layer is preferably, for example, a layer containing resin.

[0187] The resin contained in the surface layer is not particularly limited, but examples include urethane monomer resins, polyester resins, phenolic resins, acrylic resins, epoxy resins, cellulose resins, etc.

[0188] The surface layer preferably contains a conductive agent, for example.

[0189] Examples of conductive agents included in the surface layer include electronic conductive agents and ionic conductive agents.

[0190] The same electronically conductive agent used in the conductive capping layer is used as the electronically conductive agent included in the surface layer. Furthermore, the same ionicly conductive agent used in the intermediate layer is used as the ionicly conductive agent included in the surface layer.

[0191] The surface layer may contain other additives depending on the required physical properties of the surface layer.

[0192] (Young's modulus of the surface layer)

[0193] From the viewpoint of improving cleanliness, the Young's modulus of the surface layer is preferably 10 MPa or more and 400 MPa or less, more preferably 50 MPa or more and 400 MPa or less, and even more preferably 100 MPa or more and 350 MPa or less.

[0194] Furthermore, the Young's modulus of the surface layer was determined using the same method as that for the elastic layer. However, a dumbbell-shaped tensile test piece with a thickness of 0.2 mm was used. This dumbbell-shaped tensile test piece was obtained by analyzing the surface layer of the target conductive roller, adding the same analyzed combination of surface layer materials to a resin with high release properties such as PTFE, and then demolding it after thermosetting.

[0195] (Thickness of the surface layer)

[0196] In the conductive roller described in this embodiment, the thickness of the surface layer can be determined according to the application of the conductive roller.

[0197] However, from the viewpoint of improving cleanliness, the thickness of the surface layer is preferably 10 μm or more and 50 μm or less, more preferably 12 μm or more and 45 μm or less.

[0198] (Volume resistivity of the surface layer)

[0199] The volume resistivity of the surface layer when a voltage of 10V is applied is preferably, for example, 10. 4 Ω or higher and 10 14 Ω or less, more preferably 10 6 Ω or higher and 10 12 Below Ω.

[0200] In addition, the volume resistivity of the surface layer was measured according to JIS K 6911 as follows.

[0201] First, the surface layer of the target conductive roller was analyzed, and a single-layer sheet component using the same combination of surface layer materials as analyzed was fabricated. The volume resistivity of the resulting sheet component was measured. The sheet component thickness was set to 0.2 mm. Between the circular electrodes, a 10 V voltage (V) was applied between the surface and back electrodes using a microcurrent meter (R8320 manufactured by ADVANTEST CORPORATION), and the current value I (A) was read after 5 seconds. The volume resistivity was then calculated using the following formula.

[0202] Formula: Volume resistivity Rv (Ω) = V / I

[0203] The method of forming the surface layer is not particularly limited. For example, a method can be given by applying a coating liquid for forming the surface layer onto an intermediate layer and drying the resulting coating film.

[0204] [Volume resistivity of the conductive roller]

[0205] In the conductive roller of this embodiment, the volume resistivity when a voltage of 1000V is applied is preferably, for example, 10. 4 Ω or higher and 10 12 Ω or less, more preferably 10 5 Ω or higher and 10 11 Ω or less, more preferably 10 6 Ω or higher and 10 10 Below Ω.

[0206] The volume resistivity of the conductive roller is determined using the same method as that used for the volume resistivity of the elastic layer.

[0207] (Volume resistivity of the conductive roller)

[0208] In the conductive roller of this embodiment, the volume resistivity when a voltage of 1000V is applied is preferably, for example, 10. 4 Ω or higher and 10 12 Ω or less, more preferably 10 5 Ω or higher and 10 11 Ω or less, more preferably 10 6 Ω or higher and 1010 Below Ω.

[0209] The volume resistivity of the conductive roller is determined using the same method as that used for the volume resistivity of the elastic layer.

[0210] <Image forming apparatus, transfer apparatus, processing box>

[0211] Figure 4 This is a schematic structural diagram of an image forming apparatus of the direct transfer method, which is an example of an image forming apparatus according to this embodiment.

[0212] Figure 4 The image forming apparatus 200 shown includes: a photoreceptor 207 (an example of an image holder); a charged roller 208 (an example of a charging unit) that charges the surface of the photoreceptor 207; an exposure apparatus 206 (an example of a static charge image forming unit) that forms a static charge image on the surface of the charged photoreceptor 207; a developing apparatus 211 (an example of a developing unit) that develops the static charge image formed on the surface of the photoreceptor 207 into a toner image using a developer containing a toner; and a transfer roller 212 (an example of a transfer unit, an example of a transfer apparatus according to this embodiment) that transfers the toner image formed on the surface of 207 to the surface of a recording medium.

[0213] Here, the conductive roller according to this embodiment is applied to the transfer roller 212, which presses its outer peripheral surface against the photosensitive element 207, which is equivalent to the opposing roller, and forms an insertion portion through which the recording paper 500 is inserted.

[0214] Figure 4 The image forming apparatus 200 shown also includes: a cleaning device 213 for removing toner residues on the surface of the photoreceptor 207; a static removal device 214 for static removal from the surface of the photoreceptor 207; and a fixing device 215 (an example of a fixing unit) for fixing the toner image onto the recording medium.

[0215] The electrified roller 208 can be energized by contact or non-contact methods. Voltage is applied to the electrified roller 208 from the power supply 209.

[0216] Exposure device 206 can be an optical device equipped with a light source such as a semiconductor laser or an LED (Light Emitting Diode).

[0217] The developing apparatus 211 is a device that supplies toner to the photoreceptor 207. The developing apparatus 211, for example, keeps the roller developer in contact with or close to the photoreceptor 207 so that the toner adheres to the electrostatic image on the photoreceptor 207, thereby forming a toner image.

[0218] The transfer roller 212 is a transfer roller that directly contacts the surface of the recording medium and is positioned opposite the photoreceptor 207. Recording paper 500 (an example of a recording medium) is supplied via a supply mechanism to the gap between the transfer roller 212 and the photoreceptor 207. When a transfer bias is applied to the transfer roller 212, an electrostatic force from the photoreceptor 207 toward the recording paper 500 acts on the toner image, transferring the toner image from the photoreceptor 207 onto the recording paper 500.

[0219] As a fixing device 215, for example, a heating fixing device that includes a heating roller and a pressure roller pressed on the heating roller can be cited.

[0220] As a cleaning device 213, an example of a device having a scraper, brush, roller or the like as cleaning components can be cited.

[0221] The static removal device 214 is, for example, a device that irradiates the surface of the transferred photoreceptor 207 with light to remove the residual potential of the photoreceptor 207.

[0222] The photoreceptor 207 and the transfer roller 212 can be, for example, an ink cartridge structure (the processing cartridge according to this embodiment) that is integrated into a frame and detachable from the image forming apparatus. The ink cartridge structure (the processing cartridge according to this embodiment) may also include at least one selected from the group consisting of the charged roller 208, the exposure device 206, the developing device 211, and the cleaning device 213.

[0223] The image forming apparatus can be a series-connected image forming apparatus, in which a photoreceptor 207, a charged roller 208, an exposure device 206, a developing device 211, a transfer roller 212, and a cleaning device 213 are configured as an image forming unit, and a plurality of such image forming units are mounted side by side.

[0224] Figure 5 This is a schematic structural diagram of an image forming apparatus using an intermediate transfer method, which is an example of an image forming apparatus according to this embodiment. Figure 5 The image forming apparatus shown is a series-connected image forming apparatus with four image forming units arranged in parallel.

[0225] exist Figure 5 In the image forming apparatus shown, the transfer unit that transfers the toner image formed on the surface of the image holder to the surface of the recording medium is configured as a transfer unit having an intermediate transfer body, a primary transfer unit, and a secondary transfer unit (an example of the transfer apparatus according to this embodiment). The transfer unit may be an ink cartridge structure that is attached to and detached from the image forming apparatus.

[0226] Figure 5The image forming apparatus shown includes: a photoreceptor 1 (an example of an image holder); a charged roller 2 (an example of a charging unit) that charges the surface of the photoreceptor 1; an exposure apparatus 3 (an example of a static charge image forming unit) that forms a static charge image on the surface of the charged photoreceptor 1; a developing apparatus 4 (an example of a developing unit) that develops the static charge image formed on the surface of the photoreceptor 1 into a toner image using a developer containing a toner; an intermediate transfer belt 20 (an example of an intermediate transfer body); a primary transfer roller 5 (an example of a primary transfer unit) that transfers the toner image formed on the surface of the photoreceptor 1 to the surface of the intermediate transfer belt 20; and a secondary transfer roller 26 (an example of a secondary transfer unit) that transfers the toner image transferred to the surface of the intermediate transfer belt 20 to the surface of a recording medium.

[0227] Here, the conductive roller involved in this embodiment is applied to a secondary transfer roller 26, which presses its outer peripheral surface against a support roller 24 that is equivalent to an opposing roller, and forms an insertion portion that allows the recording paper P to pass through.

[0228] Figure 5 The image forming apparatus shown also includes: a fixing device 28 (an example of a fixing unit) for fixing a toner image onto a recording medium; a photoreceptor cleaning device 6 for removing toner residues on the surface of the photoreceptor 1; and an intermediate transfer belt cleaning device 30 for removing toner residues on the surface of the intermediate transfer belt 20.

[0229] Figure 5 The image forming apparatus shown includes first to fourth image forming units 10Y, 10M, 10C, and 10K in an electrophotographic mode that outputs images of each color—yellow (Y), magenta (M), cyan (C), and black (K)—based on color-separated image data. These image forming units 10Y, 10M, 10C, and 10K are arranged side-by-side in a horizontal direction. The image forming units 10Y, 10M, 10C, and 10K can be individually mounted and detached from the processing unit of the image forming apparatus.

[0230] Above each image forming unit 10Y, 10M, 10C, and 10K, an intermediate transfer belt 20 extends through each image forming unit. The intermediate transfer belt 20 is wound around a drive roller 22 and a support roller 24 that are in contact with the inner surface of the intermediate transfer belt 20, and travels in a direction from the first image forming unit 10Y toward the fourth image forming unit 10K. The support roller 24 is subjected to force in a direction away from the drive roller 22 by a spring (not shown), and the intermediate transfer belt 20 wound around both is subjected to tension. On the image holding side of the intermediate transfer belt 20, opposite the drive roller 22, an intermediate transfer belt cleaning device 30 is provided.

[0231] The developing devices 4Y, 4M, 4C, and 4K of each image forming unit 10Y, 10M, 10C, and 10K are respectively supplied with yellow, magenta, cyan, and black toners contained in toner cartridges 8Y, 8M, 8C, and 8K.

[0232] Since the first to fourth image forming units 10Y, 10M, 10C and 10K have the same structure and operation, the first image forming unit 10Y will be used as the representative in the following description of the image forming units.

[0233] The first image forming unit 10Y includes: a photoreceptor 1Y; a charged roller 2Y for charging the surface of the photoreceptor 1Y; a developing device 4Y for developing the electrostatically charged image formed on the surface of the photoreceptor 1Y into a toner image using a developer containing toner; a primary transfer roller 5Y for transferring the toner image formed on the surface of the photoreceptor 1Y to the surface of the intermediate transfer belt 20; and a photoreceptor cleaning device 6Y for removing the toner residue remaining on the surface of the photoreceptor 1Y after the primary transfer.

[0234] The charged roller 2Y charges the surface of the photoreceptor 1Y. The charged roller 2Y can be charged by contact or non-contact methods.

[0235] A laser beam 3Y is irradiated from the exposure device 3 onto the surface of the charged photoreceptor 1Y. As a result, an electrostatically charged image of a yellow image pattern is formed on the surface of the photoreceptor 1Y.

[0236] Within the developing apparatus 4Y, for example, a statically charged image developer containing at least a yellow toner and a carrier is contained. The yellow toner becomes triboelectrically charged through agitation within the developing apparatus 4Y. As the surface of the photoreceptor 1Y gradually passes through the developing apparatus 4Y, the statically charged image formed on the photoreceptor 1Y is developed into a toner image.

[0237] A primary transfer roller 5Y is positioned inside the intermediate transfer belt 20 and opposite the photoreceptor 1Y. A bias power supply (not shown) is connected to the primary transfer roller 5Y to apply a primary transfer bias voltage. The primary transfer roller 5Y transfers the toner image on the photoreceptor 1Y onto the intermediate transfer belt 20 by electrostatic force.

[0238] On the intermediate transfer belt 20, the toner images of each color are sequentially multi-transferred from the first to the fourth image forming units 10Y, 10M, 10C, and 10K. The intermediate transfer belt 20, which has multi-transferred the toner images of the four colors through the first to the fourth image forming units, reaches the secondary transfer unit composed of the support roller 24 and the secondary transfer roller 26.

[0239] The secondary transfer roller 26 is a transfer roller that directly contacts the surface of the recording medium, and is positioned opposite the support roller 24 on the outside of the intermediate transfer belt 20. Recording paper P (an example of the recording medium) is supplied via a supply mechanism to the gap between the secondary transfer roller 26 and the intermediate transfer belt 20. If a secondary transfer bias is applied to the secondary transfer roller 26, an electrostatic force from the intermediate transfer belt 20 toward the recording paper P acts on the toner image, transferring the toner image from the intermediate transfer belt 20 onto the recording paper P.

[0240] Recording paper P, with a toner image transferred onto it, is fed into the pressing section (engaging section) of a fixing device 28 consisting of a pair of rollers, and the toner image is fixed onto the recording paper P.

[0241] The toner and developer used in the image forming apparatus according to this embodiment are not particularly limited, and any known electrophotographic toner and developer can be used.

[0242] The recording medium used in the image forming apparatus according to this embodiment is not particularly limited, and examples include paper used in electrophotographic copiers or printers; OHP sheets; etc.

[0243] Example

[0244] The following describes embodiments, but the present invention is not limited to these embodiments in any way. Furthermore, in the following description, unless otherwise stated, "parts" and "%" are both mass terms.

[0245] <Example 1>

[0246] [Formation of the elastic layer]

[0247] (Formation of elastic foam)

[0248] As an elastic foam, EP70 (polyurethane foam manufactured by INOAC CORPORATION) is used and cut into cylindrical shapes with an outer diameter of 26 mm and an inner diameter of 14 mm to obtain a cylindrical elastic foam.

[0249] The resulting elastic foam has a continuous bubble structure, with a unit diameter of 400 μm and a density of 70 kg / m³. 3 .

[0250] (Formation of a conductive capping layer)

[0251] The elastic foam obtained by the above method was impregnated at 20°C for 10 minutes in a treatment solution containing 36% by mass of carbon black and a 1:1 mass ratio of a dispersed aqueous dispersion and an acrylic emulsion (manufactured by Zeon Corporation, trade name "Nipol LX852").

[0252] The elastic foam coated with the treatment liquid was then heated and dried in a curing oven set to 100°C for 60 minutes to remove moisture and crosslink the acrylic resin. The crosslinked and cured acrylic resin formed a conductive coating containing carbon black on the exposed surface of the elastic foam.

[0253] As described above, an elastic layer is obtained, consisting of an elastic foam and a conductive covering layer that covers the exposed surface of the elastic foam.

[0254] Next, a conductive support component (manufactured by SUS, 14 mm in diameter) with an adhesive applied to the surface is inserted into the resulting elastic layer, thereby forming the roller component.

[0255] [Formation of the intermediate layer]

[0256] A coating liquid for forming an intermediate layer was prepared by mixing 70 parts of urethane oligomer (manufactured by NIHON GOSEI KAKO Co., Ltd., urethane acrylate UV3700B), 30 parts of urethane monomer (manufactured by KYOEISHA CHEMICAL CO.,LTD., isonutmeg acrylate), 0.5 parts of polymerization initiator (manufactured by Ciba Specialty Chemicals Co., Ltd., 1-hydroxycyclohexylphenyl ketone Irgacure 184), and 3 parts of alkyl trimethylammonium percolate (trade name "LXN-30", manufactured by Daiso-sangyo). The resulting coating liquid was then applied to an elastic layer using a die coater while the layer was rotated and irradiated with a UV intensity of 700 mW / cm². 2 The coating was irradiated with UV light for 5 seconds. This process created an intermediate layer with a thickness of 1 mm.

[0257] [Formation of the surface layer]

[0258] Next, 5% by weight of a curing agent (WH-1, manufactured by Henkel Japan Ltd.) was added to the urethane resin coating (EMRALON T-862A, manufactured by Henkel Japan Ltd.) and mixed to obtain a surface layer forming coating liquid. The obtained surface layer forming coating liquid was applied to the intermediate layer by spraying and the coating was cured at 120°C for 20 minutes to form a surface layer with a thickness of 20 μm.

[0259] As described above, a volume resistivity value of 10 was obtained. 6.8 A conductive roller with an Ω (measured value when 1000V is applied).

[0260] <Example 2>

[0261] When the intermediate layer is formed, the UV irradiation intensity is 650 mW / cm. 2 The coating was irradiated with UV light for 5 seconds, and otherwise the conductive roller was obtained in the same manner as in Example 1.

[0262] <Example 3>

[0263] When the intermediate layer is formed, the UV irradiation intensity is 600 mW / cm. 2 The coating was irradiated with UV light for 5 seconds, and otherwise the conductive roller was obtained in the same manner as in Example 1.

[0264] <Example 4>

[0265] The urethane resin coating on the surface layer was set to ST-008E (manufactured by UBE INDUSTRIES, LTD.), and a surface layer with a thickness of 40 μm was formed. Otherwise, a conductive roller was obtained in the same manner as in Example 2.

[0266] <Example 5>

[0267] When forming the elastic layer, EP69 (polyurethane foam manufactured by INOAC CORPORATION) was used as the elastic foam, and a surface layer with a thickness of 8 μm was formed. Otherwise, the conductive roller was obtained in the same manner as in Example 2.

[0268] <Example 6>

[0269] A surface layer with a thickness of 10 μm was formed, and otherwise, a conductive roller was obtained in the same manner as in Example 2.

[0270] <Example 7>

[0271] A surface layer with a thickness of 60 μm is formed, and otherwise, a conductive roller is obtained in the same manner as in Example 2.

[0272] <Example 8>

[0273] When forming the elastic layer, EP70 (polyurethane foam manufactured by INOAC CORPORATION) was used as the elastic foam. Carbon black was pre-mixed in urethane resin and then foamed. No conductive coating layer was formed. Otherwise, the conductive roller was obtained in the same manner as in Example 2.

[0274] <Example 9>

[0275] When forming the elastic layer, RMM (polyurethane foam manufactured by INOAC CORPORATION) is used as the elastic foam, otherwise, the conductive roller is obtained in the same manner as in Example 2.

[0276] <Example 10>

[0277] An elastic layer was formed as follows, and otherwise a conductive roller was obtained in the same manner as in Example 2.

[0278] [Formation of the elastic layer]

[0279] (Formation of elastic foam)

[0280] 60 parts of EPDM (ethylene-propylene-diene rubber, Esplen 505 manufactured by Sumitomo Chemical Co., Ltd.) as the rubber component were mixed in a pressure kneader. 7 parts of 4,4'-oxobis(benzenesulfonyl hydrazine) (OBSH) as a chemical foaming agent, 12 parts of acetylene black (manufactured by Denka Company Limited, DBP oil absorption = 212 ml / 100 g) as a conductive agent, 23 parts of thermal carbon black (manufactured by ASAHI CARBON CO.,LTD., DBP oil absorption = 103 ml / 100 g) as a thermal black, 5 parts of zinc oxide (manufactured by Nippon Chemical Industrial CO.,LTD.) as a filler, 1.5 parts of vulcanization accelerator (Noxeller TS, manufactured by OUCHI SHINKO CHEMICAL INDUSTRIAL CO.,LTD.) and vulcanization accelerator (Noxeller DT, OUCHI SHINKO CHEMICAL INDUSTRIAL) as a chemical foaming agent, were added. (manufactured by CO.,LTD.) 1.5 parts were then mixed using two heated rollers. The mixture was then inserted into a SUS core metal. In the process, roller-shaped foaming molding is used to form roller components.

[0281] (Formation of a conductive capping layer)

[0282] The elastic foam obtained by the above method was impregnated at 20°C for 10 minutes in a treatment solution containing 36% by mass of carbon black and a 1:1 mass ratio of a dispersed aqueous dispersion and an acrylic emulsion (manufactured by Zeon Corporation, trade name "Nipol LX852").

[0283] The elastic foam coated with the treatment liquid was then heated and dried in a curing oven set to 100°C for 60 minutes to remove moisture and crosslink the acrylic resin. The crosslinked and cured acrylic resin formed a conductive coating containing carbon black on the exposed surface of the elastic foam.

[0284] As described above, an elastic layer is obtained, consisting of an elastic foam and a conductive covering layer that covers the exposed surface of the elastic foam.

[0285] <Examples 11-15>

[0286] The thicknesses of the elastic layer and the intermediate layer were changed to the values ​​shown in Table 1. Otherwise, the conductive roller was obtained in the same manner as in Example 1.

[0287] <Example 16>

[0288] The surface layer of urethane resin coating is designated as “UW-2001A” (manufactured by UBE INDUSTRIES, LTD.), and otherwise, the conductive roller is obtained in the same manner as in Example 1.

[0289] <Examples 17-19>

[0290] When forming the elastic layer, PELightA-8 (polyethylene foam manufactured by INOAC CORPORATION), RR26 (polyurethane foam manufactured by INOAC CORPORATION), and RR90 (polyurethane foam manufactured by INOAC CORPORATION) were used as elastic foams, respectively. Otherwise, the conductive roller was obtained in the same manner as in Example 1.

[0291] <Comparative Example 1>

[0292] When the intermediate layer is formed, the UV irradiation intensity is 850 mW / cm. 2 The coating was irradiated with UV light for 5 seconds, and otherwise the conductive roller was obtained in the same manner as in Example 1.

[0293] <Comparative Example 2>

[0294] When the intermediate layer is formed, the UV irradiation intensity is 850 mW / cm. 2 The coating was irradiated with UV light for 5 seconds, and otherwise the conductive roller was obtained in the same manner as in Example 9.

[0295] <Evaluation>

[0296] (Parallelism of the image transferred to the recording medium)

[0297] Using an ApeosPort VII C6688 manufactured by Fuji Xerox Co., Ltd., the secondary transfer roller was configured with a Rear indentation of 0.2 mm and a Front indentation of 0.8 mm onto the opposing intermediate transfer belt, with a Rear-Front difference of 0.6 mm. A 280 mm × 400 mm rectangular line was imaged onto the intermediate transfer belt at A3 size, transferred by the secondary transfer unit, and fixed by the fixing unit. The image line lengths (L) on the Rear and Front sides of the output image were then measured. Rear L Front ), calculate the image length difference (L) relative to the original image length of 400mm. Front )-(L Rear ), calculate the parallelism ΔL (reference) Figure 1 (b)

[0298] -Evaluation Criteria-

[0299] A(〇): ΔL>1.5mm

[0300] B(△): 0.5mm < ΔL < 1.5mm

[0301] C(×): 0.5mm > ΔL

[0302] (Cleanliness)

[0303] The fabricated double transfer rollers were installed on an ApeosPort VII C6688 manufactured by Fuji Xerox Co., Ltd., and a K100% solid image was output onto A3 paper, single-sided. The back of the output paper after 100 images were printed was observed to confirm the presence of toner stains on the back.

[0304] -Evaluation Criteria-

[0305] A(〇): The back side is completely uncontaminated.

[0306] B(△): Part of the back side is colored black.

[0307] C(×): The back is colored black in a stripe pattern.

[0308]

[0309] As can be seen from the above results, compared with the conductive roller of the comparative example, the conductive roller of this embodiment can easily improve the parallelism of the image transferred onto the recording medium.

[0310] The embodiments of the present invention described above are provided for illustrative purposes. Furthermore, these embodiments do not encompass the entirety of the invention, nor do they limit the invention to the disclosed methods. It will be apparent to those skilled in the art that various modifications and variations will be readily understood. These embodiments were chosen and described to most readily explain the principles and applications of the invention. Thus, those skilled in the art can understand the invention through various modifications that are assumed to be optimized for specific uses of various embodiments. The scope of the invention is defined by the foregoing claims and their equivalents.

Claims

1. A conductive roller, comprising: Support components; An elastic layer is disposed on the outer peripheral surface of the support member; A surface layer, disposed on the outer peripheral surface of the elastic layer; and An intermediate layer, disposed between the elastic layer and the surface layer, has a Poisson's ratio of 0.40 or less.

2. The conductive roller according to claim 1, wherein, The thickness Td of the elastic layer, the thickness Tm of the intermediate layer, and the thickness Ts of the surface layer satisfy the relationship Td > Tm > Ts.

3. The conductive roller according to claim 2, wherein, The thickness Td of the elastic layer, the thickness Tm of the intermediate layer, and the thickness Ts of the surface layer satisfy the relationship 0.07≤Tm / (Td+Tm+Ts)≤0.

43.

4. The conductive roller according to claim 2 or 3, wherein, The thickness Tm of the intermediate layer is greater than 0.5 mm and less than 4 mm.

5. The conductive roller according to any one of claims 2 to 4, wherein, The thickness Ts of the surface layer is greater than 10 μm and less than 50 μm.

6. The conductive roller according to any one of claims 1 to 5, wherein, The Young's modulus Ys of the surface layer is above 10 MPa and below 400 MPa.

7. The conductive roller according to any one of claims 1 to 6, wherein, The elastic layer comprises a cylindrical elastic foam and a conductive covering layer that covers the exposed surface of the elastic foam.

8. The conductive roller according to claim 7, wherein, The elastic foam has a continuous bubble structure.

9. The conductive roller according to claim 7 or 8, wherein, The density of the elastic foam is 50 kg / m³. 3 Above and 90kg / m 3 the following.

10. A transfer apparatus comprising a conductive roller according to any one of claims 1 to 9.

11. A processing cartridge comprising an image holding body and the transfer device of claim 10, and detachable from an image forming apparatus.

12. An image forming apparatus comprising: Image holding volume; A charging device that charges the surface of the image holder. An electrostatic latent image forming apparatus forms an electrostatic latent image on the surface of the charged image holder; A developing apparatus that develops an electrostatic latent image formed on the surface of the image holder using a developer containing a toner to form a toner image; and The transfer apparatus of claim 10 transfers the toner image onto the surface of the recording medium.

Images