Cleaning member, charging device, process cartridge, and image forming device

Abstract

To provide a cleaning member which offers superior capability to suppress an increase in resistance of a cleaning target.SOLUTION: A cleaning member is provided, comprising a core material and a foam elastic layer provided on the core material, the foam elastic material containing at least one selected from a group consisting of polyacrylic acids, acrylic acid copolymers, and salts of the aforementioned.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a cleaning member, a charging device, a process cartridge, and an image forming apparatus. [Background technology]

[0002] Patent Document 1 discloses a charging member that comes into contact with a body to be charged while a voltage is applied thereto, thereby charging the body, and that is characterized in that the surface of the charging member is coated with tetrahedral amorphous carbon.

[0003] Patent Document 2 describes a foamed elastic layer having a core body, a foamed elastic layer wound spirally around the outer circumferential surface of the core body from one end to the other end of the core body, and an adhesive layer bonding the core body and the foamed elastic layer, wherein the diameter of the tip of the cell skeleton protruding from the surface of the foamed elastic layer is 50 μm or less, and when the inner circumferential length of the foamed elastic layer in the cross section in the radial direction of the core body is X (mm) and the thickness of the foamed elastic layer is Y (mm), X×Y 2 The cleaning body has a value of 45 or more. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2006-276068 [Patent Document 2] Japanese Patent Application Publication No. 2023-98354 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present disclosure is to provide a cleaning member in which the foamed elastic layer is superior in suppressing an increase in resistance of an object to be cleaned, compared to when the foamed elastic layer is made of only a foamed resin. [Means for solving the problem]

[0006] Specific means for solving the above problems include the following aspects. <1> A cleaning member having a core material and a foamed elastic layer on the core material, the foamed elastic layer containing at least one selected from the group consisting of polyacrylic acid, acrylic acid copolymers and salts thereof. <2> The foamed elastic layer further contains water-containing particles containing water therein. <1> The conductive member according to claim 1. <3> The total content of the at least one selected from the group consisting of polyacrylic acid, acrylic acid copolymers, and salts thereof is 0.2% by mass or more and 8% by mass or less with respect to the total mass of the foamed elastic layer. <1> or <2> The cleaning member according to claim 1. <4> the total content of at least one selected from the group consisting of polyacrylic acid, acrylic acid copolymers, and salts thereof is 1% by mass or more and 3% by mass or less with respect to the total mass of the foamed elastic layer; <3> The cleaning member according to claim 1. <5> The content of the water-containing particles containing water therein is 0.05% by mass or more and 1% by mass or less with respect to the total mass of the foamed elastic layer. <2> The cleaning member according to claim 1. <6> The side surface of the foamed elastic layer is observed, and the number of water-containing particles containing water therein per 300 μm square on the side surface is 10 or more and 100 or less. <2> or <5> The cleaning member according to claim 1. <7> The at least one selected from the group consisting of polyacrylic acid, acrylic acid copolymers, and salts thereof has an arithmetic mean particle size of 10 μm or more and 100 μm or less. <1> ~ <6> 10. The cleaning member according to claim 9, wherein the cleaning member is a cleaning member having a thickness of 100 μm or more. <8> The arithmetic mean particle size of the water-containing particles containing water therein is 0.2 μm or more and 1.0 μm or less. <2> , <5> or <6> The cleaning member according to claim 1. <9> The foamed elastic layer is wound spirally around the outer circumferential surface of the core material from one end to the other end of the core material. <1> ~ <8> 10. The cleaning member according to claim 9, wherein the cleaning member is a cleaning member having a thickness of 100 μm or more. <10> <1> ~ <9> 10. A charging device comprising the cleaning member according to any one of claims 1 to 9. <11> <10> A process cartridge equipped with the charging device according to claim 1, which is detachably mounted on an image forming apparatus. <12> an image carrier and charging the surface of the image carrier; <10> an electrostatic latent image forming device that forms an electrostatic latent image on the charged surface of the image carrier; a developing device that develops the electrostatic latent image formed on the surface of the image carrier with a developer containing toner to form a toner image; and a transfer device that transfers the toner image to the surface of a recording medium. [Effects of the Invention]

[0007] <1> or <9> According to the invention, a cleaning member is provided which is superior in suppressing an increase in resistance of the object to be cleaned compared to when the foamed elastic layer is made of only foamed resin. <2> According to the invention, a cleaning member is provided that is more excellent in suppressing an increase in resistance of an object to be cleaned than when the foamed elastic layer does not further contain water-containing particles that contain water therein. <3> According to the invention, a cleaning member is provided that is more excellent in suppressing an increase in resistance of the object to be cleaned than when the total content of at least one selected from the group consisting of polyacrylic acid, acrylic acid copolymers, and salts thereof is less than 0.2 mass % or more than 8 mass % relative to the total mass of the foamed elastic layer. <4> According to the invention, a cleaning member is provided which is superior in suppressing an increase in resistance of the object to be cleaned, compared to when the total content of at least one selected from the group consisting of polyacrylic acid, acrylic acid copolymers, and salts thereof is less than 1 mass % or more than 3 mass % relative to the total mass of the foamed elastic layer. <5> According to the invention, a cleaning member is provided that is better at suppressing an increase in resistance of the object to be cleaned than when the content of the water-containing particles containing water inside is less than 0.05 mass % or more than 1 mass % relative to the total mass of the foamed elastic layer. <6> According to the invention, a cleaning member is provided which is superior in suppressing an increase in resistance of the object to be cleaned when the side of the foamed elastic layer is observed and the number of water-containing particles containing water inside per 300 μm square on the side is less than 10 or more than 100. <7> According to the invention, a cleaning member is provided which is more excellent at suppressing an increase in resistance of an object to be cleaned than when the arithmetic mean particle size of at least one selected from the group consisting of polyacrylic acid, acrylic acid copolymers, and salts thereof is less than 10 μm or more than 100 μm. <8> According to the invention, a cleaning member is provided that is better at suppressing an increase in resistance of the object to be cleaned than when the arithmetic mean particle size of the water-containing particles that contain water inside is less than 0.2 μm or more than 1.0 μm. <10> ~ <12> According to the invention, a charging device, a process cartridge, or an image forming apparatus is provided in which the foamed elastic layer in the cleaning member is better at suppressing an increase in the resistance of the object being cleaned by the cleaning member than when the foamed elastic layer is made of foamed resin alone. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a schematic perspective view illustrating an example of a cleaning member according to the present embodiment. [Figure 2] FIG. 2 is a schematic plan view illustrating an example of a cleaning member according to the present embodiment. [Figure 3] 2 is a schematic cross-sectional view of an example of a cleaning member according to the present embodiment, taken parallel to the radial direction of a core material. FIG. [Figure 4A] 5A to 5C are process diagrams illustrating an example of a method for manufacturing the cleaning member according to the present embodiment. [Figure 4B] 5A to 5C are process diagrams illustrating an example of a method for manufacturing the cleaning member according to the present embodiment. [Figure 4C] 5A to 5C are process diagrams illustrating an example of a method for manufacturing the cleaning member according to the present embodiment. [Figure 5] 1 is a schematic configuration diagram illustrating an example of an image forming apparatus according to an embodiment of the present invention. [Figure 6] FIG. 1 is a schematic diagram illustrating an example of an assembly according to an embodiment of the present invention. [Figure 7] FIG. 7 is an enlarged schematic diagram of the charging device and its surrounding area in FIGS. 5 and 6. DETAILED DESCRIPTION OF THE INVENTION

[0009]

[0023] The following describes embodiments of the present disclosure. These descriptions and examples are intended to illustrate the embodiments and are not intended to limit the scope of the embodiments.

[0010] In the present disclosure, a numerical range indicated using "to" indicates a range that includes the numerical values ​​before and after "to" as the minimum and maximum values, respectively. In the numerical ranges described in stages in this disclosure, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. Furthermore, in the numerical ranges described in this disclosure, the upper or lower limit value of that numerical range may be replaced with a value shown in the examples. In the present disclosure, the term "step" includes not only an independent step but also a step that cannot be clearly distinguished from other steps as long as the purpose of the step is achieved. When embodiments of the present disclosure are described with reference to the drawings, the configuration of the embodiment is not limited to the configuration shown in the drawings. The size of the components in each drawing is conceptual, and the relative size relationships between the components are not limited thereto. Components having the same function and action are given the same reference numerals throughout the drawings, and their description may be omitted. In the present disclosure, each component may contain multiple corresponding substances. When referring to the amount of each component in a composition in the present disclosure, if multiple substances corresponding to each component are present in the composition, the total amount of the multiple substances present in the composition is meant unless otherwise specified. In the present disclosure, the composition may contain multiple types of particles corresponding to each component. When multiple types of particles corresponding to each component are present in the composition, the particle size of each component means the value for a mixture of the multiple types of particles present in the composition, unless otherwise specified.

[0011] (cleaning materials) The cleaning member according to this embodiment has a core material and a foamed elastic layer on the core material, and the foamed elastic layer contains at least one selected from the group consisting of polyacrylic acid, acrylic acid copolymers, and salts thereof. The cleaning member according to this embodiment is preferably used as a cleaning member for a charging device, and more preferably used as a cleaning member for a charging roll.

[0012] Image forming devices with conventional cleaning members have a problem in that as the device moves, external additives and other deposits adhere to the object being cleaned and begin to accumulate, covering the entire surface of the object being cleaned.As the layer becomes thicker, resistance increases, affecting image formation. In the cleaning member according to this embodiment, the foamed elastic layer contains at least one selected from the group consisting of polyacrylic acid, acrylic acid copolymers, and salts thereof. This causes the acrylic acid or acrylic acid copolymer contained in the foamed elastic layer to absorb moisture due to humidity, supplied water, etc., and this moisture is supplied to the object to be cleaned during cleaning. This moisture imparts conductivity to the deposits and improves the removability of the deposits, thereby suppressing an increase in the resistance of the object to be cleaned.

[0013] Furthermore, when the cleaning member according to this embodiment is used as a cleaning member for a charging device, the increase in the potential of the image carrier (also called a photosensitive member) is also suppressed.

[0014] The cleaning member according to this embodiment will be described with reference to the drawings.

[0015] <Foamed elastic layer> The foamed elastic layer contains at least one selected from the group consisting of polyacrylic acid, acrylic acid copolymers, and salts thereof (hereinafter also referred to as "water-absorbent resin").

[0016] From the viewpoint of suppressing an increase in the resistance of the object to be cleaned, the water-absorbing resin is preferably at least one selected from the group consisting of polyacrylic acid and salts thereof, and from the viewpoint of ease of adjusting the physical properties, the water-absorbing resin is preferably at least one selected from the group consisting of acrylic acid copolymers and salts thereof. Examples of the acrylic acid copolymer include a styrene-acrylic acid copolymer, a (meth)acrylic acid ester-acrylic acid copolymer, and a styrene-(meth)acrylic acid ester-acrylic acid copolymer. Furthermore, the amount of monomer units derived from acrylic acid in the acrylic acid copolymer is preferably 20% by mass or more, more preferably 50% by mass or more, and even more preferably 70% by mass or more but less than 100% by mass, relative to the total mass of the acrylic acid copolymer. The salt in the water-absorbent resin is not particularly limited, but from the viewpoint of suppressing an increase in the resistance of the object to be cleaned and facilitating adjustment of physical properties, it is preferably a salt of a monovalent or divalent cation, more preferably a salt of a monovalent cation, even more preferably an ammonium salt or an alkali metal salt, and particularly preferably a sodium salt. The water-absorbing resin may also be a crosslinked resin.

[0017] The shape of the water-absorbing resin is not particularly limited, but from the viewpoint of suppressing an increase in the resistance of the object to be cleaned, it is preferably in the form of particles. That is, from the viewpoint of suppressing an increase in the resistance of the object to be cleaned, it is preferable that the foamed elastic layer contains at least one type of resin particles (water-absorbing resin particles) selected from the group consisting of polyacrylic acid, acrylic acid copolymers, and salts thereof.

[0018] The arithmetic mean particle size of the water-absorbing resin particles when dry is preferably 1 μm to 500 μm, more preferably 2 μm to 300 μm, even more preferably 5 μm to 200 μm, and particularly preferably 10 μm to 100 μm, from the viewpoint of suppressing an increase in the resistance of the object to be cleaned and suppressing an increase in the potential of the photosensitive member.

[0019] The arithmetic mean particle size of the water-absorbent resin particles is determined by the following measurement method. The measurement is performed by removing the water-absorbent resin particles from the foamed elastic layer, or by observing the surface of the foamed elastic layer. A method for removing the water-absorbent resin particles from the foamed elastic layer includes, for example, immersing the foamed elastic layer peeled off from the cleaning member in an organic solvent that dissolves the foamed resin, and removing the water-absorbent resin particles by dissolving the foamed resin with the organic solvent. The removed water-absorbent resin particles or the foamed elastic layer are dried (for example, dried under reduced pressure), and the removed water-absorbent resin particles or the water-absorbent resin particles on the surface of the foamed elastic layer are observed with a scanning electron microscope, and the circle-equivalent diameters of 100 randomly selected primary particles are determined, and the arithmetic mean value of the circle-equivalent diameters is defined as the arithmetic mean particle diameter.

[0020] The content of the water-absorbing resin particles in the foamed elastic layer when dry is preferably from 0.2% by mass to 8% by mass, more preferably from 0.5% by mass to 5% by mass, and particularly preferably from 1% by mass to 3% by mass, relative to the total mass of the foamed elastic layer, from the viewpoint of suppressing an increase in the resistance of the object to be cleaned and suppressing an increase in the potential of the photosensitive body.

[0021] Furthermore, from the viewpoint of suppressing an increase in the resistance of the object to be cleaned and suppressing an increase in the potential of the photoreceptor, it is preferable that the water-absorbing resin, preferably the water-absorbing resin particles, be present on the surface of the foamed elastic layer in an amount of 50% by mass or more relative to the total mass of the water-absorbing resin, including pores on the surface due to foaming.

[0022] Furthermore, from the viewpoint of suppressing an increase in the resistance of the object to be cleaned and suppressing an increase in the potential of the photosensitive body, it is preferable that the foamed elastic layer further contains water-containing particles that contain water therein, and it is more preferable that the foamed elastic layer further contains a resin that contains water therein.

[0023] Examples of water-containing particles that contain water inside include water-containing microcapsules and water-containing microgels. Among these, from the viewpoint of suppressing an increase in the resistance of the object to be cleaned and suppressing an increase in the potential of the photosensitive member, microcapsules containing water are preferred, and microcapsules containing water whose capsule wall material is made of resin are more preferred.

[0024] The components of the capsule wall material (i.e., outer shell) of the microcapsules are not particularly limited, and known materials can be used. Among them, resins are preferred from the viewpoint of suppressing an increase in the resistance of the object to be cleaned and an increase in the potential of the photosensitive member. Examples of resins used in capsule wall materials include polyurethane, polyurea, polyester, polyether, polyolefin, polyamide, polyvinyl chloride, acrylic resin, styrene-ethylene-butylene-styrene block copolymer (SEBS), styrene-butadiene-styrene block copolymer (SBS), styrene-isoprene-styrene block copolymer (SIS), and styrene-ethylene-propylene-styrene block copolymer (SEPS).

[0025] The arithmetic mean particle size of the water-containing particles is preferably 0.01 μm to 50 μm, more preferably 0.05 μm to 10 μm, even more preferably 0.1 μm to 5.0 μm, and particularly preferably 0.2 μm to 1.0 μm, from the viewpoint of suppressing an increase in the resistance of the object to be cleaned and suppressing an increase in the potential of the photosensitive member.

[0026] The arithmetic mean particle size of the water-containing particles is determined by the following measurement method. The water-containing particles are measured by removing them from the foamed elastic layer or by observing the surface of the foamed elastic layer. For example, the water-containing particles can be removed from the foamed elastic layer by peeling the foamed elastic layer from the cleaning member and transferring the water-containing particles with an adhesive conductive tape. The removed water-containing particles or the water-containing particles on the surface of the foamed elastic layer are observed under a scanning electron microscope, and the circle-equivalent diameters of 100 randomly selected primary particles are determined. The arithmetic mean particle size is the arithmetic mean of the circle-equivalent diameters.

[0027] From the viewpoint of suppressing an increase in the resistance of the object to be cleaned and an increase in the potential of the photosensitive member, the content of the water-containing particles in the foamed elastic layer is preferably from 0.01% by mass to 5% by mass, more preferably from 0.05% by mass to 1% by mass, and particularly preferably from 0.1% by mass to 0.8% by mass, relative to the total mass of the foamed elastic layer.

[0028] From the viewpoint of suppressing an increase in the resistance of the object to be cleaned and an increase in the potential of the photoreceptor, it is preferable that the water-containing particles are present on the surface of the foamed elastic layer in an amount of 50% by mass or more relative to the total mass of the water-containing particles, including pores on the surface due to foaming.

[0029] Furthermore, when observing the side of the foamed elastic layer, the number of water-containing particles that contain water inside per 300 μm square on the side is preferably 5 to 500, more preferably 8 to 200, and particularly preferably 10 to 100, from the viewpoint of suppressing an increase in the resistance of the object to be cleaned and suppressing an increase in the potential of the photosensitive body.

[0030] The number of water-containing particles containing water therein is measured by observing a 300 μm square area of ​​the surface of the side surface of the foamed elastic layer with a scanning electron microscope and counting the number of water-containing particles.

[0031] Examples of materials for the foamed elastic layer include foamable resins such as polyurethane, polyethylene, polyamide, and polypropylene; and rubber materials such as silicone rubber, fluororubber, urethane rubber, EPDM (ethylene propylene diene rubber), NBR (acrylonitrile-butadiene rubber), CR (chloroprene rubber), chlorinated polyisoprene, isoprene, styrene-butadiene rubber, hydrogenated polybutadiene, and butyl rubber. These materials may be used alone or in combination of two or more. These materials may also contain foaming agents, foaming aids, foam stabilizers, catalysts, curing agents, plasticizers, vulcanizing agents, vulcanization aids, and vulcanization accelerators.

[0032] The foamed elastic layer is preferably made of foamed polyurethane that is resistant to tension, from the viewpoint of preventing scratches on the surface of the member to be cleaned due to friction and preventing tearing or breakage over a long period of time.

[0033] Examples of foamed polyurethane include reaction products of polyols (e.g., polyester polyols, polyether polyols, acrylic polyols, etc.) with isocyanates (e.g., 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, tolidine diisocyanate, 1,6-hexamethylene diisocyanate, etc.), and may also be reaction products obtained by further reacting with a chain extender (1,4-butanediol, trimethylolpropane). Polyurethane foaming is generally carried out using a foaming agent such as water or an azo compound (e.g., azodicarbonamide, azobisisobutyronitrile, etc.). Foaming aids, foam stabilizers, catalysts, etc. may also be added to the foamed polyurethane.

[0034] The density of the foam elastic layer is 60 kg / m 3 More than 100kg / m 3 Less than 65 kg / m 3 More than 95kg / m 3 Less than 70 kg / m is more preferable. 3 More than 90kg / m 3 The following is even more preferred:

[0035] The foam diameter of the foamed elastic layer is preferably 5 μm or more and 500 μm or less, more preferably 10 μm or more and 200 μm or less, and particularly preferably 20 μm or more and 100 μm or less.

[0036] The foam diameter of the foamed elastic layer is measured by observing the foamed elastic layer at multiple locations with a laser microscope, binarizing the observation images obtained from a field of view of n5 or more, and determining the circle-equivalent diameter of 100 bubbles (voids) randomly selected from the circles in the image, and taking the arithmetic mean of the circle-equivalent diameters as the arithmetic mean particle diameter.

[0037] <Core material> Examples of materials for the core include metals, alloys, and resins. Examples of metals or alloys include metals such as iron (free-cutting steel, etc.), copper, brass, aluminum, and nickel; and alloys such as stainless steel. Examples of resins include polyacetal resins and polycarbonate resins. One type of resin may be used alone, or two or more types may be used in combination.

[0038] The surface of the core material may be surface-treated. If the core material is made of metal, it is preferable to apply a plating treatment. If the core material is made of a non-conductive material (e.g., resin), it may be subjected to a conductive treatment such as plating.

[0039] <Adhesive layer> The cleaning member according to this embodiment may have an adhesive layer between the core material and the foamed elastic layer. The material of the adhesive layer is not particularly limited as long as it can bond the core material and the foamed elastic layer. Examples of the adhesive layer include double-sided tape and adhesives.

[0040] 1 and 2 are shown as examples of the cleaning member according to this embodiment, but it goes without saying that the present invention is not limited to these. FIG. 1 is a schematic perspective view showing an example of a cleaning member according to the present embodiment. 2 is a schematic plan view showing an example of a cleaning member according to the present embodiment.

[0041] 1 and 2 is a member including a core material 102, a foamed elastic layer 104, and an adhesive layer 106. The core material 102 and the foamed elastic layer 104 are bonded together by the adhesive layer 106.

[0042] The core material 102 is a rod-shaped or cylindrical member. The diameter of the core material 102 is preferably 2 mm or more and 12 mm or less, more preferably 3 mm or more and 10 mm or less, and even more preferably 4 mm or more and 8 mm or less.

[0043] The foamed elastic layer 104 is a layer formed by spirally winding a strip-shaped foamed elastic material, and is a layer arranged spirally at intervals on the outer peripheral surface of the core material 102 from one end to the other end of the core material 102.

[0044] The cleaning member 100 may have an area at the end in the axial direction that does not need to exhibit cleaning performance for the member to be cleaned. In this case, the foamed elastic layer 104 may not be disposed in the end of the cleaning member 100.

[0045] The foamed elastic layer 104 spirally wound around the core material 102 may be either right-handed or left-handed.

[0046] The cleaning member 100 may have a foamed elastic layer 104 with multiple stripes (for example, two stripes). The foamed elastic layer 104 with multiple stripes (for example, two stripes) is a layer that is independent of each other and is formed by spirally winding a plurality of strips (for example, two strips) of foamed elastic material around the outer peripheral surface of the core material 102. The foamed elastic layer 104 with multiple stripes may be arranged spaced apart from each other, or may be arranged with their longitudinal sides in contact with each other. By providing the foamed elastic layer 104 with multiple independent stripes, the cleaning performance of the cleaning member 100 is improved.

[0047] The adhesive layer 106 has, for example, approximately the same width and length as the foamed elastic layer 104. When the cleaning member 100 has a plurality of ribs of the foamed elastic layer 104, the adhesive layer 106 may be a layer of separate ribs for each of the plurality of ribs of the foamed elastic layer 104, or may be a single layer on which the plurality of ribs of the foamed elastic layer 104 are placed.

[0048] When the inner circumferential length of the foamed elastic layer 104 in the radial cross section of the core 102 is X (mm) and the thickness of the foamed elastic layer 104 is Y (mm), the cleaning member 100 has an area of ​​X×Y 2 The value of is 45 or greater. The foamed elastic layer 104 is arranged by being wound spirally around the core material 102, and is fixed to the core material 102 in a deformed state. The foamed elastic layer 104 fixed in a deformed state has a greater force to restore its original shape, i.e., a greater force to peel off from the adhesive layer 106, as the value of X increases and as the value of Y increases. On the other hand, X×Y 2 The larger the value of , the greater the cleaning effect due to compression and deformation of the foamed elastic layer 104.

[0049] The inner perimeter length X (mm) of the foamed elastic layer 104 in a cross section taken in the radial direction of the core 102 is the average of the dimensions of the cross section of the cleaning member 100 taken parallel to the radial direction of the core 102, and is the average of the inner perimeter length of the foamed elastic layer 104 in the cross section of the foamed elastic layer 104. With the cleaning member 100 fixed in the circumferential direction, the inner perimeter length of the foamed elastic layer 104 in the cross section is measured for each spiral turn (for example, if the spiral has seven turns, measurements are taken at seven locations), and the arithmetic average value is the inner perimeter length X (mm). The measurement may be performed by a destructive method that creates a cross section of the foamed elastic layer 104, or by a non-destructive method (for example, a method using a laser scanning size measuring device) that does not destroy the foamed elastic layer 104. If the cleaning member 100 has multiple stripes of the foamed elastic layer 104, the inner perimeter X is determined for each stripe.

[0050] 3 is a cross-sectional view of the cleaning member 100 taken parallel to the radial direction of the core 102 (i.e., a cross-sectional view taken along the AA direction in FIG. 2). The average inner periphery length of the foamed elastic layer 104 in the cross section of the foamed elastic layer 104 is the inner periphery length X (mm). In the cleaning member 100 shown in FIG. 3, the width of the foamed elastic layer 104 and the width of the adhesive layer 106 are the same, so in the cross section shown in FIG. 3, the length of the inner periphery of the foamed elastic layer 104 is, in other words, the length of the boundary between the foamed elastic layer 104 and the adhesive layer 106.

[0051] The thickness Y (mm) of the foamed elastic layer 104 is a value measured by the following measurement method. Using a laser scanning dimension measuring device (for example, a laser scanning micrometer manufactured by Mitutoyo Corporation), the cleaning element 100 is scanned in the axial direction at a traverse speed of 1 mm / s while the circumferential direction of the cleaning element 100 is fixed, to obtain a thickness profile of the foamed elastic layer 104. The same scan is performed three times, shifting the circumferential direction by 120°. The thickness Y (mm) of the foamed elastic layer 104 is calculated from the three profiles. If the cleaning element 100 has multiple stripes of the foamed elastic layer 104, the thickness Y is determined for each stripe.

[0052] The inner peripheral length X of the foamed elastic layer 104 in the radial cross section of the core material 102 is preferably 4 mm or more, more preferably 6 mm or more, and even more preferably 8 mm or more, from the viewpoint of preventing the foamed elastic layer 104 from peeling off from the adhesive layer 106 and of achieving excellent cleaning performance for the member to be cleaned. The inner periphery length X of the foamed elastic layer 104 in the radial cross section of the core 102 is preferably 14 mm or less, more preferably 12 mm or less, and even more preferably 10 mm or less, from the viewpoint of stabilizing the winding process.

[0053] The thickness Y of the foamed elastic layer 104 is preferably 1 mm or more, more preferably 2 mm or more, and even more preferably 4 mm or more, from the viewpoint of excellent cleaning performance for the member to be cleaned. From the viewpoint of stabilizing the winding process, the thickness Y of the foamed elastic layer 104 is preferably 8 mm or less, more preferably 7 mm or less, and even more preferably 6 mm or less.

[0054] The helical angle θ of the foamed elastic layer 104 is preferably greater than 15° and less than or equal to 45° from the viewpoints of preventing the foamed elastic layer 104 from peeling off the adhesive layer 106 and of achieving excellent cleaning performance for the member to be cleaned. The helical angle θ refers to the angle (acute angle) at which the longitudinal direction P (helical direction) of the foamed elastic layer 104 intersects with the axial direction Q of the core material 102, as shown in FIG. When the helical angle θ is greater than 15°, resistance is reduced when the foamed elastic layer 104 comes into contact with the member to be cleaned, suppressing peeling of the foamed elastic layer 104. Furthermore, when the helical angle θ is greater than 15°, the number of turns of the foamed elastic layer 104 is relatively large, resulting in excellent cleaning performance for the member to be cleaned. From these viewpoints, the helical angle θ is more preferably 18° or greater, and even more preferably 20° or greater. When the helical angle θ is 45° or less, deformation and restoring force of the foamed elastic layer 104 are suppressed, and peeling of the foamed elastic layer 104 is suppressed. From this viewpoint, the helical angle θ is more preferably 40° or less, and further preferably 35° or less.

[0055] From the viewpoints of excellent cleaning performance for the member to be cleaned and ease of rotation of the cleaning member 100 following the member to be cleaned, the number of turns of the foamed elastic layer 104 around the core 102 is preferably 3 or more, more preferably 4 or more, and even more preferably 5 or more. The upper limit of the number of turns of the foamed elastic layer 104 is not particularly limited because it depends on the length of the core 102.

[0056] The coverage of the foamed elastic layer 104 with respect to the core material 102 is preferably 30% or more, more preferably 35% or more, and even more preferably 40% or more, from the viewpoint of excellent cleaning performance for the member to be cleaned. The coverage of the foamed elastic layer 104 with respect to the core material 102 is preferably 70% or less, more preferably 65% ​​or less, and even more preferably 55% or less, from the viewpoint of preventing any deposits adhering to the surface of the foamed elastic layer 104 from transferring back to the member to be cleaned. The coverage is {width W1 of the foamed elastic layer 104 ÷ (width W1 of the foamed elastic layer 104 + spacing W2 of the foamed elastic layer 104)}. The width W1 and spacing W2 of the foamed elastic layer 104 refer to the length of the foamed elastic layer 104 and the length between the foamed elastic layers 104 along the axial direction Q of the core material 102, as shown in FIG. 2 .

[0057] The width W1 of the foamed elastic layer 104 is preferably 5 mm or more and 25 mm or less, more preferably 6 mm or more and 20 mm or less, and even more preferably 8 mm or more and 15 mm or less.

[0058] <Method of manufacturing the cleaning member 100> 4A, 4B, and 4C are process diagrams showing an example of a method for manufacturing the cleaning member 100.

[0059] First, a foamed elastic material (e.g., foamed polyurethane) is sliced ​​to the desired thickness to obtain a foamed elastic sheet (e.g., foamed polyurethane sheet). In order to control the diameter of the tips of the cell skeleton protruding from the surface of the foamed elastic layer to 50 μm or less, for example, the surface of the foamed elastic material is ground when slicing.

[0060] Next, double-sided tape is attached to one side of the foamed elastic sheet. A strip-shaped foamed elastic member having the desired length and width is cut out from the foamed elastic sheet with double-sided tape. The double-sided tape may be attached to one side of the strip-shaped foamed elastic member after it is cut out from the foamed elastic sheet. Through the above process, a strip-shaped member (see FIG. 4A) is obtained in which double-sided tape 100D is attached to one side of strip-shaped foamed elastic member 100C.

[0061] The core 100A, which is a rod-shaped member, is prepared. The core 100A comes into contact with the core 102 of the cleaning member 100.

[0062] The length of the foamed elastic member 100C is determined by the axial length of the core 100A, the winding angle of the foamed elastic member 100C (the spiral angle θ of the cleaning member 100), and the tension when winding the foamed elastic member 100C.

[0063] Next, place the foamed elastic member 100C on a table with the double-sided tape 100D attached to it facing up, and peel off one end of the release paper from the double-sided tape 100D. Next, as shown in Figure 4B, place one end of the core 100A on the double-sided tape 100D from which the release paper has been peeled off. At this time, the positions of the core 100A and the foamed elastic member 100C are determined so that the helical angle θ of the cleaning member 100 is achieved.

[0064] Next, while peeling off the release paper from the double-sided tape 100D, the core material 100A is rotated to spirally wrap the foamed elastic member 100C around the outer peripheral surface of the core material 100A (see Figure 4C), and the foamed elastic layer 100B (the foamed elastic layer 104 in the cleaning member 100) is arranged spirally around the outer peripheral surface of the core material 100A.

[0065] From the viewpoint of reducing the restoring force of the foamed elastic layer 104 in the cleaning member 100 and preventing the longitudinal ends of the foamed elastic layer 104 from peeling off from the core 102, it is preferable to wind the foamed elastic member 100C around the core 100A while suppressing the degree of elastic deformation (change in thickness of the member) of the foamed elastic member 100C. Specifically, it is preferable to control the winding angle of the foamed elastic member 100C and the tension when winding the foamed elastic member 100C according to the thickness of the foamed elastic member 100C.

[0066] When applying tension to the foamed elastic member 100C when wrapping it around the core 100A, the tension should be such that no gaps form between the foamed elastic member 100C and the double-sided tape 100D. Specifically, the tension should be such that the length of the foamed elastic member 100C is more than 100% but not more than 105%. If too much tension is applied, it becomes difficult to suppress the restoring force of the foamed elastic layer 104 in the cleaning member 100, and the permanent tensile elongation increases, which tends to reduce the elastic force of the foamed elastic layer 104 required for cleaning.

[0067] When the foamed elastic member 100C is wound around the core 100A, the foamed elastic member 100C tends to stretch. This stretching varies in the thickness direction of the foamed elastic member 100C, with the outermost periphery stretching the most. This stretching is controlled by the radius of curvature at which the foamed elastic member 100C is wound around the core 100A and the thickness of the foamed elastic member 100C, and the radius of curvature at which the foamed elastic member 100C is wound around the core 100A is controlled by the outer diameter of the core 100A and the winding angle of the foamed elastic member 100C. Specifically, for example, it is preferable that the outermost periphery of the foamed elastic layer 104 of the cleaning member 100 stretch about 105% of the outermost periphery of the foamed elastic member 100C.

[0068] The radius of curvature at which the foamed elastic member 100C wraps around the core material 100A is preferably between {(core material outer diameter / 2) + 0.2 mm} and {(core material outer diameter / 2) + 8.5 mm}, and more preferably between {(core material outer diameter / 2) + 0.5 mm} and {(core material outer diameter / 2) + 7.0 mm}.

[0069] There are no particular limitations on the method for introducing the water-absorbing resin (not shown) and water-containing particles (not shown) into the foamed elastic member 100C, but examples include a method in which the water-absorbing resin and water-containing particles are mixed into the material when the foamed elastic member 100C is produced and then introduced; and a method in which the foamed elastic member 100C is wrapped around the core material 100A, and the water-absorbing resin (preferably water-absorbing resin particles) and water-containing particles are brought into contact with the surface of the foamed elastic member 100C, and are then adhered to the surface of the foamed elastic member 100C (including the pores created by foaming) and introduced therein. Among these, a preferred method is to wrap foamed elastic material 100C around core material 100A, bring water-absorbing resin particles and water-containing particles into contact with the surface of foamed elastic material 100C, and allow them to adhere to and be introduced onto the surface of foamed elastic material 100C.

[0070] (Cleaning device) The cleaning device according to the present embodiment includes a cleaning member according to the present embodiment and a member to be cleaned. The member to be cleaned is a rotating member, and the cleaning member is a member that comes into contact with the rotating member to be cleaned and cleans the member to be cleaned while rotating. The cleaning member according to the present embodiment is used as the cleaning member.

[0071] The cleaning device according to this embodiment is a cartridge-type cleaning device that is detachably attached to, for example, an electrophotographic image forming apparatus. Examples of members to be cleaned include a charged body, a transfer roll, a transfer belt, and a conveyor belt. The cleaning member removes toner, paper dust, and the like that adhere to the surfaces of these members to be cleaned.

[0072] (Image forming devices, charging devices, process cartridges) The charging device according to this embodiment is a charging device that includes the cleaning member according to this embodiment. The process cartridge according to this embodiment is a process cartridge that includes a charging device and is detachably mounted in an image forming apparatus. The image forming apparatus according to this embodiment includes an image carrier, a charging device according to this embodiment that charges the surface of the image carrier, an electrostatic latent image forming device that forms an electrostatic latent image on the charged surface of the image carrier, a developing device that develops the electrostatic latent image formed on the surface of the image carrier using a developer containing toner to form a toner image, and a transfer device that transfers the toner image to the surface of a recording medium.

[0073] Fig. 5 is a schematic diagram showing an example of an image forming apparatus according to the present embodiment. Fig. 6 is a schematic diagram showing an example of an assembly according to the present embodiment. Fig. 7 is a schematic diagram showing an enlarged view of the charging device and its surroundings in Figs. 5 and 6.

[0074] 5 is a tandem, direct transfer color image forming apparatus. Inside the apparatus body 10A of the image forming apparatus 10, process cartridges 18Y, 18M, 18C, and 18K for yellow (Y), magenta (M), cyan (C), and black (K) are provided.

[0075] The process cartridges 18Y, 18M, 18C, and 18K are detachably mountable to the image forming apparatus 10. The process cartridges 18Y, 18M, 18C, and 18K each include a photosensitive member 12, a charging member 14, and a developing device 19, as shown in FIGS.

[0076] The photoreceptor 12 is driven to rotate by a motor (not shown). The surface of the photoreceptor 12 is charged by a charging member 14 arranged on the surface of the photoreceptor 12. After being charged, the photoreceptor 12 is exposed to a laser beam emitted from an exposure device 16 downstream in the direction of rotation of the photoreceptor 12, and an electrostatic image is formed on the photoreceptor 12. The electrostatic image formed on the photoreceptor 12 is developed into a toner image by a developing device 19. The surface of the photoreceptor 12 for each color undergoes the processes of charging, exposure, and development, and a toner image corresponding to that color is formed on the surface of the photoreceptor 12 for each color.

[0077] The toner image formed on the photoreceptor 12 is transferred to the recording medium 24 transported on the transport belt 20 at a location where the photoreceptor 12 and the transfer member 22 come into contact with each other via the transport belt 20. The transfer member 22 is, for example, a roll having a conductive elastic layer on the outer peripheral surface of a conductive support, which is rotatably supported within the image forming apparatus 10. The transport belt 20 is supported from its inner peripheral surface while being tensioned by support rolls 40 and 42, and transports the recording medium 24. The recording medium 24 is taken out of a storage container 28 by a take-out roller 30 and transported to the transport belt 20 by transport rolls 32 and 34.

[0078] The toner images of each color are transferred onto the recording medium 24 in the order of the four process cartridges, that is, in the order of black (K), cyan (C), magenta (M), and yellow (Y).

[0079] The recording medium 24 onto which the toner image has been transferred is transported to a fixing device 64, where it is heated and pressurized to fix the toner image onto the recording medium 24. Thereafter, in the case of single-sided printing, the recording medium 24 onto which the toner image has been fixed is discharged by a discharge roll 66 onto a discharge section 68 provided at the top of the image forming apparatus 10. In the case of double-sided printing, the recording medium 24 onto which the toner image has been fixed on its first side (front side) is transported to a transport path 70 for double-sided printing by the reverse rotation of the discharge roll 66. The recording medium 24 is then transported onto the transport belt 20 again by a transport roll 72 provided on the transport path 70, with the recording medium 24 turned upside down, and the toner image from the photoreceptor 12 is transferred to the second side (back side) of the recording medium 24. The recording medium 24 onto which the toner image has been transferred on its second side (back side) is then transported to the fixing device 64, where the toner image is fixed onto the recording medium 24 by the fixing device 64. Thereafter, the recording medium 24 with the toner images fixed on both sides is discharged onto a discharge section 68 by a discharge roll 66 .

[0080] After the transfer of the toner image is completed, the photoreceptor 12 is cleaned by the cleaning blade 80 with each rotation of the photoreceptor 12 to remove residual toner and paper dust from the surface of the photoreceptor 12 in preparation for the next image formation.

[0081] As shown in FIG. 7, the charged member 14 is a roll member having a conductive elastic layer 14B on the outer peripheral surface of a support 14A. The support 14A is a conductive cylindrical or columnar body. The support 14A is supported rotatably within the image forming apparatus. The conductive elastic layer 14B is laminated in a cylindrical shape on the outer peripheral surface of the support 14A. The conductive elastic layer 14B is, for example, a layer in which a conductive agent is dispersed in a foamed or non-foamed rubber material.

[0082] A cleaning member 100 for the charged body 14 is disposed on the opposite side of the charged body 14 from the photoreceptor 12, in contact with the charged body 14. In other words, the charged body 14 and the cleaning member 100 constitute a charging device (unit) (see FIGS. 6 and 7). The cleaning member according to this embodiment is used as the cleaning member 100. The cleaning member 100 may be, for example, any of a member that is in constant contact with the charged body 14 and rotates in accordance with the charged body 14, a member that is in contact with the charged body 14 only during cleaning and rotates in accordance with the charged body 14, or a member that is in contact with the charged body 14 only during cleaning and rotates by a separate drive.

[0083] 7, for example, a load F is applied to both ends of the support 14A, and the charged member 14 is pressed against the photoreceptor 12. This causes the conductive elastic layer 14B to elastically deform, forming a nip portion along the outer peripheral surface of the photoreceptor 12. 7, for example, a load F' is applied to both ends of the core 102, and the cleaning member 100 is pressed against the charged body 14. This causes the foamed elastic layer 104 to elastically deform, forming a nip portion along the outer circumferential surface of the charged body 14.

[0084] 7, the photosensitive member 12 is driven to rotate in the direction of arrow X by a motor (not shown), and the rotation of the photosensitive member 12 causes the charged member 14 to rotate in the direction of arrow Y. Furthermore, the rotation of the charged member 14 causes the cleaning member 100 to rotate in the direction of arrow Z.

[0085] Although examples of the image forming apparatus and process cartridge according to the present embodiment have been described above using FIGS. 5, 6 and 7, the present embodiment is not limited to this. The image forming apparatus according to the present embodiment is not limited to the tandem and direct transfer type shown in Fig. 5, and well-known image forming apparatuses such as intermediate transfer type ones may be applied. Furthermore, the image forming apparatus according to the present embodiment may have internal devices and components directly arranged therein rather than being made into cartridges. The process cartridge equipped with a charging device may be a process cartridge equipped with a charging device (a unit of a charging member and a cleaning member) and also equipped with at least one selected from a photosensitive member, an exposure device, a developing device, and a transfer device.

[0086] The member to be cleaned, the surface of which is cleaned by the cleaning member according to this embodiment, is not limited to a charged body such as a charging roll. Other examples of the member to be cleaned include a photosensitive body, a transfer member, a paper transport belt, a secondary transfer member of an intermediate transfer system (e.g., a secondary transfer roll), and an intermediate transfer member of an intermediate transfer system (e.g., an intermediate transfer belt). These members to be cleaned and the cleaning member arranged in contact therewith may be combined into a unit to form a process cartridge that is detachable from the image forming apparatus.

[0087] Hereinafter, an embodiment of a charged body (that is, a charged body provided in the charging device according to the present embodiment) will be described in detail as an example of a member to be cleaned whose surface is cleaned by the cleaning member according to the present embodiment.

[0088] The charged body has, for example, a support and a conductive elastic layer. The conductive elastic layer may be a single layer or a laminate of multiple layers. The conductive elastic layer may be a layer whose surface has been surface-treated, or a surface layer containing a polymer material may be further laminated on the outer peripheral surface of the conductive elastic layer.

[0089] Examples of the material for the support include free-cutting steel, stainless steel, etc., and the surface may be plated. When the material is not conductive, it may be subjected to a treatment to make it conductive, such as plating.

[0090] The conductive elastic layer contains an elastic material such as rubber and a conductive agent such as carbon black or an ionic conductive agent. For example, the conductive agent is dispersed in the elastic material. The conductive elastic layer may further contain a softener, a plasticizer, a curing agent, a vulcanizing agent, a vulcanization aid, a vulcanization accelerator, an antioxidant, a lubricant, a filler (silica, calcium carbonate, etc.), etc. The conductive elastic layer is formed by coating the outer surface of a conductive support with a mixture of the above materials. The elastic material may be a foam, in which case the conductive elastic layer becomes a conductive foamed elastic layer.

[0091] Examples of elastic materials constituting the conductive elastic layer include silicone rubber, ethylene propylene rubber, epichlorohydrin rubber, epichlorohydrin-ethylene oxide copolymer rubber, epichlorohydrin-ethylene oxide-allyl glycidyl ether copolymer rubber, acrylonitrile-butadiene copolymer rubber, and mixtures thereof. One type of elastic material may be used alone, or two or more types may be used in combination.

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

[0093] The conductive agent may be used alone or in combination of two or more. The amount of conductive agent is not particularly limited, but in the case of an electronic conductive agent, it is preferably in the range of 1 part by mass to 60 parts by mass per 100 parts by mass of the elastic material, and in the case of an ionic conductive agent, it is preferably in the range of 0.1 parts by mass to 5.0 parts by mass per 100 parts by mass of the elastic material.

[0094] The surface of the charged body may be provided with a surface layer containing a polymer material. Examples of the polymer material contained in the surface layer include polyvinylidene fluoride, tetrafluoroethylene copolymer, polyester, polyimide, copolymer nylon, and silicone resin. One of the above polymer materials may be used alone, or two or more may be used in combination.

[0095] The surface layer may contain a conductive material to adjust the resistance value. Examples of the conductive material include carbon black, conductive metal oxide particles, and ionic conductive agents. One type of conductive material may be used alone, or two or more types may be used in combination. The surface layer may contain insulating particles such as alumina and silica. [Example]

[0096] Hereinafter, embodiments of the present invention will be described in detail using examples, but the embodiments of the present invention are not limited to these examples. In the following description, unless otherwise specified, "parts" and "%" are based on mass. In the following description, synthesis, processing, production, etc. were carried out at room temperature (25°C ± 3°C) unless otherwise specified.

[0097] <Production of charging roll> - Formation of conductive elastic layer - Epichlorohydrin-ethylene oxide-allyl glycidyl ether copolymer rubber (GECHRON3106, manufactured by Zeon Corporation): 100 parts Carbon black (Asahi Thermal, manufactured by Asahi Carbon Co., Ltd.): 25 parts Ketjenblack EC (manufactured by Lion Specialty Chemicals Co., Ltd.): 8 parts Ion conductive agent (lithium perchlorate): 1 part Sulfur (200 mesh, manufactured by Tsurumi Chemical Industry Co., Ltd.): 1 part Vulcanization accelerator (Noccela DM, manufactured by Ouchi Shinko Chemical Industry Co., Ltd.): 2 parts Vulcanization accelerator (Noccela TT, manufactured by Ouchi Shinko Chemical Industry Co., Ltd.): 0.5 parts The above materials were kneaded in an open roll to obtain a composition for forming an elastic layer. The outer surface of a support made of SUS416, with a diameter of 9 mm and a total length of 370 mm, was coated with a 1.5 mm thick composition for forming an elastic layer, placed in a cylindrical mold with an inner diameter of 12.0 mm, and vulcanized at 170°C for 30 minutes. After removal from the mold, the outer surface of the conductive elastic layer was polished to obtain an elastic roll.

[0098] - Formation of surface layer - Copolymer nylon (Amilan (registered trademark) CM8000, manufactured by Toray Industries, Inc.): 20 parts Antimony-doped tin oxide (SN-100P, manufactured by Ishihara Sangyo Kaisha): 30 parts Methanol: 500 parts Butanol: 240 parts The above materials were dispersed in a bead mill. The resulting dispersion was applied to the outer surface of an elastic roll by dip coating, and then heated and dried at 140°C for 15 minutes to form a surface layer with a thickness of 4 μm. This produced a charging roll.

[0099] Example 1 <Production of cleaning member (cleaning roll)> A metal core material made of SUM24EZ with a diameter of 5.0 mm and a total length of 360 mm was prepared as the core material. Urethane foam (FHS, manufactured by Inoac Corporation, foam diameter 40 μm) was prepared as the material for the foamed elastic layer.

[0100] The urethane foam was sliced ​​to the desired thickness to obtain a urethane foam sheet. A 0.15 mm thick double-sided tape (No. 501L, manufactured by Nitto Denko Corporation) was attached to the entire surface of one side of the urethane foam sheet. The urethane foam sheet with double-sided tape was cut to the desired length and width to obtain a strip-shaped member with double-sided tape.

[0101] The strip-shaped member with double-sided tape was placed on a horizontal table with the release paper of the double-sided tape facing up, and while the release paper was removed, tension was applied to the strip-shaped member with double-sided tape so that the total length of the strip-shaped member was elongated by approximately 0% to 5%. The metal core material was rolled on the table to wrap the strip-shaped member with double-sided tape around the metal core material, resulting in a metal core material with a foamed elastic layer. The helical angle θ of the foamed elastic layer was 25°, the inner circumferential length X of the foamed elastic layer in the radial cross section of the core material was 5 mm, and the thickness Y of the foamed elastic layer was 3 mm.

[0102] Aqualic CS (registered trademark) 8S (particles of acrylic acid polymer partially cross-linked with sodium salt, manufactured by Nippon Shokubai Co., Ltd., average particle size 10 μm to 100 μm) was uniformly spread on a tray (tray), and the resulting metal core material having a foamed elastic layer was rolled to introduce the particles into the foamed elastic layer, thereby producing a cleaning member (cleaning roll). The content of the particles relative to the total mass of the foamed elastic layer is shown in Table 1.

[0103] Example 2 A cleaning member was prepared in the same manner as in Example 1, except that the number of times the metal core material having the foamed elastic layer was rolled on the bat was increased and the content of the particles relative to the total mass of the foamed elastic layer was set to the value shown in Table 1.

[0104] Example 3 <Preparation of Water-Containing Particles A> 10 parts of styrene monomer was added to 15°C water and stirred, and toluene containing 0.1 parts of the polymerization initiator benzophenone was added dropwise. Phase inversion was performed to obtain a dispersion in which toluene was the continuous phase. The temperature inside the system was maintained at 15°C. Polymerization was initiated by irradiating ultraviolet (UV) light from a high-pressure mercury lamp power supply HB100P-1(5), causing the polymer to precipitate at the interface of the particulate water phase in the dispersion, forming resin particles containing water. The average particle size was 0.2 μm. The toluene organic solvent, which was the continuous phase, was dried to obtain a powder of resin particles containing water (water-containing particles A).

[0105] The cleaning member was prepared in the same manner as in Example 1, except that the water-containing particles A were mixed with Aqualic CS (registered trademark) 8S in an amount of 1 / 10 the mass of the Aqualic CS (registered trademark) 8S to be spread on the bat, the mixture was spread on the bat, and the number of times the metal core material having the foamed elastic layer was rolled on the bat was increased, so that the content of the particles and the content of the water-containing particles A relative to the total mass of the foamed elastic layer were set to the values ​​shown in Table 1.

[0106] Example 4 A cleaning member was prepared in the same manner as in Example 1, except that the number of times the metal core material having the foamed elastic layer was rolled on the bat was increased and the content of the particles relative to the total mass of the foamed elastic layer was set to the value shown in Table 1.

[0107] Example 5 A cleaning member was produced in the same manner as in Example 2, except that the foam diameter of the foamed elastic layer was changed from 40 μm to 60 μm.

[0108] Example 6 A cleaning member was produced in the same manner as in Example 3, except that the foam diameter of the foamed elastic layer was changed from 40 μm to 60 μm.

[0109] (Comparative Example 1) A cleaning member was prepared in the same manner as in Example 1, except that the metal core material having the foamed elastic layer was not rolled on a bat and the content of the particles relative to the total mass of the foamed elastic layer was set to the value shown in Table 1.

[0110] Example 7 A cleaning member was prepared in the same manner as in Example 1, except that the number of times the metal core material having the foamed elastic layer was rolled on the bat was increased and the content of the particles relative to the total mass of the foamed elastic layer was set to the value shown in Table 1.

[0111] Example 8 Cleaning members were prepared in the same manner as in Example 1, except that the metal core material having the foamed elastic layer was rolled on the bat more times and further inserted by hand so that the content of the particles relative to the total mass of the foamed elastic layer was the value shown in Table 1.

[0112] <Preparation of charging device> A charging device was assembled by combining a charging roll with either the cleaning member of the example or the comparative example.

[0113] <Performance evaluation> -Measurement of the potential Vh on the photosensitive drum and the resistance of the object to be cleaned (charging roll)- A long-term run (1.5M cycles) was performed using the DocuCentre-V C2275 model, after which a single halftone image was printed in black at 50% density. The potential Vh on the photoconductor was measured when the image was being produced. After removal, the resistance of the charging roll was measured using a measuring jig (R12702A / B resistivity chamber: manufactured by Advantest) and a high resistance measuring device (R8340A digital high resistance / micro current meter: manufactured by Advantest). A voltage adjusted to create an electric field (applied voltage / charging roll thickness) of 1000 V / cm was applied for 30 seconds, and the resistance was calculated using the following formula from the current value that flowed. Volume resistivity (Ω cm) = (19.63 x applied voltage (V)) / (current value (A) x measurement sample thickness (cm)) (temperature 10°C, humidity 15%) The evaluation results are shown in Table 1.

[0114] [Table 1]

[0115] The contents of the water-absorbent resin particles and the water-containing particles in Table 1 are amounts when the total mass of the foamed elastic layer is taken as 100 parts by mass. Furthermore, Vh in Table 1 is the potential Vh on the photosensitive member measured by the above method. The number of particles present on the side surface of the water-encapsulating particles obtained in Example 3 was approximately 120. The number of particles present on the side surface of the water-encapsulating particles obtained in Example 6 was approximately 150.

[0116] As shown in Table 1, the cleaning members of Examples 1 to 8 according to this embodiment are superior to the cleaning member of Comparative Example 1 in suppressing an increase in the resistance of the object to be cleaned. Furthermore, as shown in Table 1, the cleaning members of Examples 1 to 4 also suppressed the decrease in the potential on the photosensitive member.

[0117] (((1))) A cleaning member having a core material and a foamed elastic layer on the core material, wherein the foamed elastic layer contains at least one selected from the group consisting of polyacrylic acid, acrylic acid copolymers, and salts thereof. (((2))) The conductive member according to (((1))), wherein the foamed elastic layer further contains water-containing particles that contain water therein. (((3))) The cleaning member according to (((1))) or (((2))), wherein the total content of the at least one selected from the group consisting of polyacrylic acid, acrylic acid copolymers, and salts thereof is 0.2% by mass or more and 8% by mass or less relative to the total mass of the foamed elastic layer. (((4))) The cleaning member according to (((3))), wherein the total content of the at least one selected from the group consisting of polyacrylic acid, acrylic acid copolymers, and salts thereof is 1% by mass or more and 3% by mass or less relative to the total mass of the foamed elastic layer. (((5))) The cleaning member according to (((2))), wherein the content of the water-containing particles containing water therein is 0.05% by mass or more and 1% by mass or less relative to the total mass of the foamed elastic layer. (((6))) The cleaning member according to (((2))) or (((5))), wherein the number of water-containing particles containing water inside per 300 μm square on the side surface of the foamed elastic layer is 10 or more and 100 or less. (((7))) The cleaning member according to any one of (((1))) to (((6))), wherein the at least one selected from the group consisting of polyacrylic acid, acrylic acid copolymers, and salts thereof has an arithmetic mean particle size of 10 μm or more and 100 μm or less. (((8))) The cleaning member according to (((2))), (((5))) or (((6))), wherein the arithmetic mean particle size of the water-containing particles that contain water therein is 0.2 μm or more and 1.0 μm or less. (((9))) A cleaning member according to any one of (((1))) to (((8))), wherein the foamed elastic layer is arranged spirally wound around the outer peripheral surface of the core material from one end to the other end of the core material. (((10))) A charging device comprising the cleaning member according to any one of (((1))) to (((9))). (((11))) A process cartridge equipped with the charging device according to (((10))), which is detachably mounted on an image forming apparatus. (((12))) An image forming apparatus comprising: an image carrier; a charging device according to (((10))) that charges the surface of the image carrier; an electrostatic latent image forming device that forms an electrostatic latent image on the charged surface of the image carrier; a developing device that develops the electrostatic latent image formed on the surface of the image carrier with a developer containing toner to form a toner image; and a transfer device that transfers the toner image to the surface of a recording medium.

[0118] According to the invention of (((1))) or (((9))), a cleaning member is provided which is superior in suppressing an increase in the resistance of the object to be cleaned compared to when the foamed elastic layer is made of only foamed resin. According to the invention (((2))), a cleaning member is provided that is more excellent at suppressing an increase in the resistance of the object to be cleaned than when the foamed elastic layer does not further contain water-containing particles that contain water inside. According to the invention related to (((3))), a cleaning member is provided which is more excellent in suppressing an increase in resistance of the object to be cleaned than when the total content of at least one selected from the group consisting of polyacrylic acid, acrylic acid copolymers, and salts thereof is less than 0.2 mass % or more than 8 mass % relative to the total mass of the foamed elastic layer. According to the invention related to (((4))), a cleaning member is provided which is more excellent in suppressing an increase in resistance of the object to be cleaned than when the total content of at least one selected from the group consisting of polyacrylic acid, acrylic acid copolymers, and salts thereof is less than 1 mass % or more than 3 mass % relative to the total mass of the foamed elastic layer. According to the invention related to (((5))), a cleaning member is provided which is superior in suppressing an increase in resistance of the object to be cleaned compared to when the content of the water-containing particles containing water inside is less than 0.05 mass % or more than 1 mass % relative to the total mass of the foamed elastic layer. According to the invention (((6))), a cleaning member is provided which is superior in suppressing an increase in resistance of the object to be cleaned when the side surface of the foamed elastic layer is observed and the number of water-containing particles containing water inside per 300 μm square on the side surface is less than 10 or more than 100. According to the invention related to (((7))), a cleaning member is provided which is more excellent in suppressing an increase in resistance of an object to be cleaned than when the arithmetic mean particle size of at least one selected from the group consisting of polyacrylic acid, acrylic acid copolymers, and salts thereof is less than 10 μm or more than 100 μm. According to the invention (((8))), a cleaning member is provided which is superior in suppressing an increase in the resistance of the object to be cleaned compared to when the arithmetic mean particle size of the water-containing particles containing water therein is less than 0.2 μm or more than 1.0 μm. According to the inventions (((10))) to (((12))), a charging device, a process cartridge or an image forming apparatus is provided in which the foamed elastic layer in the cleaning member is better at suppressing an increase in the resistance of the object to be cleaned by the cleaning member than when the foamed elastic layer is made of foamed resin alone. [Explanation of symbols]

[0119] 100 cleaning member, 102 core material, 104 foam elastic layer, 106 adhesive layer, 100A Core material, 100B Foam elastic layer, 100C Foam elastic member, 100D Double-sided tape, 10 image forming apparatus, 10A apparatus main body, 12 photosensitive member, 14 charged member, 14A support, 14B conductive elastic layer, 16 exposure device, 19 developing device, 20 conveyor belt, 22 transfer member, 24 recording medium, 64 fixing device, 66 discharge roll, 68 discharge section, 70 conveyance path, 72 conveyance roll, 80 cleaning blade

Claims

1. A core material and a foamed elastic layer on the core material, The foamed elastic layer contains at least one selected from the group consisting of polyacrylic acid, acrylic acid copolymers, and salts thereof. Cleaning materials.

2. The cleaning member according to claim 1 , wherein the foamed elastic layer further comprises water-containing particles containing water therein.

3. 2. The cleaning member according to claim 1, wherein the total content of the at least one selected from the group consisting of polyacrylic acid, acrylic acid copolymers, and salts thereof is 0.2% by mass or more and 8% by mass or less with respect to the total mass of the foamed elastic layer.

4. 4. The cleaning member according to claim 3, wherein the total content of the at least one selected from the group consisting of polyacrylic acid, acrylic acid copolymers, and salts thereof is 1% by mass or more and 3% by mass or less with respect to the total mass of the foamed elastic layer.

5. 3. The cleaning member according to claim 2, wherein the content of the water-containing particles containing water therein is 0.05% by mass or more and 1% by mass or less with respect to the total mass of the foamed elastic layer.

6. 3. The cleaning member according to claim 2, wherein the number of water-containing particles containing water therein per 300 μm square on the side surface of the foamed elastic layer is 10 to 100.

7. 2. The cleaning member according to claim 1, wherein the at least one selected from the group consisting of polyacrylic acid, acrylic acid copolymers, and salts thereof has an arithmetic mean particle size of 10 [mu]m or more and 100 [mu]m or less.

8. 3. The cleaning member according to claim 2, wherein the water-containing particles have an arithmetic mean particle size of 0.2 [mu]m or more and 1.0 [mu]m or less.

9. 2. The cleaning member according to claim 1, wherein the foamed elastic layer is wound spirally around the outer circumferential surface of the core from one end to the other end of the core.

10. A charging device comprising the cleaning member according to any one of claims 1 to 9.

11. The charging device according to claim 10, A process cartridge is detachably mounted in an image forming apparatus.

12. an image carrier; The charging device according to claim 10, which charges the surface of the image carrier; an electrostatic latent image forming device that forms an electrostatic latent image on the charged surface of the image carrier; a developing device that develops the electrostatic latent image formed on the surface of the image carrier with a developer containing toner to form a toner image; a transfer device that transfers the toner image onto a surface of a recording medium. Image forming device.

Images