Electrophotographic roller, process cartridge, and electrophotographic image forming apparatus

Abstract

To provide an electrophotographic roller which is less likely to cause fogging even when printing is continuously performed on talcum paper and is capable of stably forming high-quality electrophotographic images.SOLUTION: An electrophotographic roller is provided, comprising a base body and a foam layer provided on an outer peripheral surface of the base body. The foam layer has a plurality of open cells on an outer surface thereof, constitutes an outer surface of the electrophotographic roller, and has a zero point charge of 40 μC / g or greater, as measured using a standard carrier.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This disclosure relates to an electrophotographic roller, a process cartridge, and an electrophotographic image forming apparatus used in an electrophotographic image forming apparatus. [Background technology]

[0002] In electrophotographic image forming apparatuses (such as photocopiers, fax machines, and printers using the electrophotographic method), an electrophotographic photoreceptor (hereinafter also referred to as the "photoreceptor") is charged by a charging roller and exposed to light, resulting in the formation of an electrostatic latent image on the photoreceptor. Next, toner in the developing container is applied onto the toner carrier by a toner supply roller and a toner regulating member. Then, the toner is transported to the developing area by the toner carrier. The toner transported to the developing area develops the electrostatic latent image on the photoreceptor between the photoreceptor and the toner carrier or the area adjacent to the toner carrier. After that, the toner on the photoreceptor is transferred to recording paper by a transfer means and fixed by heat and pressure, and any toner remaining on the photoreceptor is removed by a cleaning blade. In electrophotographic image forming apparatuses, rollers equipped with a foamed elastic layer are frequently used. For example, Patent Document 1 discloses a foamed elastic roller having a resin film containing hydrotalcite compounds on its circumferential surface. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2009-217035 [Overview of the project] [Problems that the invention aims to solve]

[0004] In recent years, various types of paper have been used in electrophotographic image forming machines. Some of these papers contain large amounts of inorganic compounds such as talc as fillers. Furthermore, when paper containing a large amount of talc (hereinafter referred to as "talc paper") is used to form electrophotographic images, a haze may occur in the electrophotographic images. The reason for this is thought to be as follows.

[0005] When talc paper comes into contact with the photoreceptor during the transfer process, some of the talc contained in the talc paper adheres to the surface of the photoreceptor. Of the talc that adheres to the surface of the photoreceptor, the smaller particles of talc pass through the cleaning area of ​​the photoreceptor, go through the charging process of the photoreceptor, and reach the position opposite the photoreceptor and the developing container. At this time, the talc (which has a much higher tendency to become negatively charged compared to toner) electrostatically adheres to the surface of the toner carrier, which is set to a higher potential than the non-image area of ​​the photoreceptor.

[0006] The toner carrier has the function of increasing the charge (charge amount) of the toner by contacting and / or rubbing it with the toner. However, if talc adheres to the surface of the toner carrier, the surface of the toner carrier cannot come into contact with the toner, and the function of increasing the charge amount of the toner is reduced. As a result, the toner with insufficient charge is developed on the surface of the photoreceptor (non-image area) where it should not be developed, resulting in a fouled image. Hereafter, this type of fouling will also be called "talc paper fouling." From this situation, it was recognized that there was a need to develop an electrophotographic roller that could more reliably remove talc adhering to the toner carrier by coming into contact with it.

[0007] One aspect of this disclosure relates to the provision of an electrophotographic roller capable of efficiently removing talc from the surface of a toner carrier. Furthermore, other embodiments of this disclosure are toward providing a process cartridge that contributes to the formation of high-quality electrophotographic images. In addition, other embodiments of this disclosure are toward providing an electrophotographic apparatus that can stably output high-quality electrophotographic images. [Means for solving the problem]

[0008] One aspect of this disclosure is, Having a substrate and a foamed layer on the outer surface of the substrate A roller for electrophotography. 、 The foamed layer but constitutes the outer surface of the electrophotographic roller, The foamed layer has a plurality of cells that open to the outer surface, The foamed layer contains particles, At least a portion of the particles is exposed from the inner wall of the cell, The particles contain a compound comprising at least one metal element, The Pauling electronegativity of the metal element is 1.70 or less. the zero-point charge of the foamed layer measured using a standard carrier is 40 μC / g or more 、 and is directed to the electrophotographic roller.

[0009] Also, another aspect of the present disclosure is directed to a process cartridge that is detachably configured on the main body of an electrophotographic image forming apparatus Ori and includes the above electrophotographic roller. Furthermore, another aspect of the present disclosure is directed to an electrophotographic image forming apparatus including the above electrophotographic roller.

Advantages of the Invention

[0010] According to one aspect of the present disclosure, an electrophotographic roller capable of efficiently removing talc on the surface of a toner carrier can be obtained. Also, according to another aspect of the present disclosure, a process cartridge contributing to the formation of high-quality electrophotographic images can be obtained. Furthermore, according to another aspect of the present disclosure, an electrophotographic apparatus capable of stably outputting high-quality electrophotographic images can be obtained.

Brief Description of the Drawings

[0011] [Figure 1] Schematic cross-sectional view of an electrophotographic roller according to one aspect of the present disclosure [Figure 2] Diagram showing the relationship between the zero-point charge related to preliminary studies and Mg / Pt and the fogging on the drum [Figure 3] Schematic configuration diagram showing a process cartridge according to one aspect of the present disclosure [Figure 4] Schematic diagram showing a process cartridge relating to one aspect of this disclosure. [Figure 5] Schematic diagram showing a process cartridge relating to one aspect of this disclosure. [Figure 6] Schematic cross-sectional view of a mold used for roller molding for electrophotography, according to one aspect of the present disclosure. [Figure 7] Diagram illustrating the method for measuring zero-point charge. [Figure 8] Diagram showing the positional relationship during zero-point charge measurement. [Figure 9] Diagram illustrating the method for calculating zero-point charge. [Figure 10] Schematic diagram of a mixing head [Figure 11] This is an enlarged cross-sectional view of a portion of the foamed layer of an electrophotographic roller according to one aspect of this disclosure. [Modes for carrying out the invention]

[0012] In this disclosure, descriptions of numerical ranges such as "XX or greater and YY or less" or "XX to YY" mean a numerical range that includes the lower and upper limits, unless otherwise specified. When numerical ranges are described in steps, the upper and lower limits of each numerical range can be combined in any way.

[0013] An electrophotographic roller according to one aspect of the present disclosure comprises a substrate and a foamed layer on the outer surface of the substrate, the foamed layer having a plurality of cells opening to the outer surface. The foamed layer constitutes the outer surface of the electrophotographic roller, and the zero-point charge of the foamed layer, measured using a standard carrier, is 40 μC / g or more.

[0014] The zero-point charge of the foamed layer is a value calculated by a method including the following steps (i) to (vii). <Calculation method> Step (i): Prepare the standard carriers P-01, P-02, N-02, and N-01 of the Image Science Society of Japan as the first to fourth reference powders, and determine the charge amount verification values ​​for the first to fourth reference powders.

[0015] Step (ii): The electrophotographic roller to be measured is heated to a temperature of 23.5°C and a relative humidity of 50°C. Leave it undisturbed in a % environment for 24 hours.

[0016] Step (iii): Under the said environment, the electrophotographic roller is placed so that its axis of rotation is horizontal, and 5 g of the first reference powder is poured down from a funnel with an inner diameter of 1.5 mm of its legs over a period of 12 seconds, with point A on the circumferential surface of the electrophotographic roller being the center of fall. The amount of charge Q of the first reference powder that falls below the electrophotographic roller and the amount Wg of the first reference powder that falls are measured, and the amount of triboelectric charge of the first reference powder is calculated using the following formula (1). Triboelectric charge Q / M [μC / g] = Q / W [1] However, point A is defined as follows: When the electrophotographic roller is placed so that its axis of rotation is horizontal, a line segment L is drawn from a plan view of the electrophotographic roller from vertically above, passing through the midpoint C in the direction along the axis of rotation of the electrophotographic roller and perpendicular to the direction along the axis of rotation. Points c1 and c2 are the points where the line segment L intersects with the electrophotographic roller, and point A is located 1 mm from point c1 toward point c2 on the line segment L, and on the outer surface of the electrophotographic roller. The funnel is positioned so that the distance between the tip of the leg of the funnel and point A is 15 mm.

[0017] Step (iv): Following step (iii), the electrophotographic roller is rotated 90° counterclockwise, and the amount of triboelectric charge on the second reference powder is calculated in the same manner as in step (iii), except that the second reference powder is used.

[0018] Step (v): Following step (iv), the electrophotographic roller is further rotated 90° counterclockwise, and the amount of triboelectric charge on the third reference powder is calculated in the same manner as in step (iii), except that the third reference powder is used.

[0019] Step (vi): Following step (v), the electrophotographic roller is further rotated 90° counterclockwise, and the amount of triboelectric charge on the fourth reference powder is calculated in the same manner as in step (iii), except that the fourth reference powder is used.

[0020] Step (vii): On a graph where the X-axis represents the charged amount of a reference powder and the Y-axis represents the amount of triboelectric charge, the four values ​​of the triboelectric charge of the first to fourth reference powders are plotted, a regression line is drawn using the least squares method, and the intersection of the regression line and the X-axis is defined as the zero-point charge of the electrophotographic roller.

[0021] By bringing a foam roller equipped with a foam layer having cells open on its surface into contact with the surface of a toner carrier, talc adhering to the toner carrier can be physically removed. However, when paper containing a large amount of talc is used continuously to form electrophotographic images, there are limitations to removing the talc adhering to the toner carrier using this physical method. Therefore, the inventors investigated electrostatically removing talc from the toner carrier by utilizing the property that talc is extremely prone to becoming negatively charged.

[0022] Specifically, in addition to physical scraping by cells opening on the surface, negatively charged tar To electrostatically adsorb the material using the foam layer, we considered increasing the positive charge properties of the foam layer. In the process, we considered using zero-point charge as an evaluation index for the charge properties of the foam layer. Zero-point charge is a parameter that represents the order of the triboelectric series. Specifically, the value of zero-point charge indicates that the object is more likely to be positively charged if the value is positive and the absolute value is large, and the object is more likely to be negatively charged if the value is negative and the absolute value is large. Zero-point charge can be calculated from the charge amount of a standard carrier whose charge amount is known and the charge amount of the standard carrier when the standard carrier is in contact with the object to be measured.

[0023] Talc, which tends to be negatively charged, is strongly attracted electrostatically to positively charged substances. Therefore, the greater the positive zero-point charge of the foam layer of the electrophotographic roller, the better the talc adhering to the surface of the component in contact with the foam layer is attracted electrostatically to the foam layer (hereinafter sometimes referred to as removal). As will be described later, this measurement directly measures the chargeability of the foam layer by bringing a standard carrier into contact with the foam layer of the electrophotographic roller.

[0024] The inventors investigated incorporating a substance that readily becomes positively charged into the foamed layer in order to increase the zero-point charge of the foamed layer to a large positive value. First, hydrotalcite particles, a substance that readily becomes positively charged, were added to the resin mixture solution before foaming, and a roller was molded. The zero-point charge of the foamed layer was then measured. However, the value of the zero-point charge hardly changed compared to the case without hydrotalcite particles. This is thought to be because the surface of the hydrotalcite particles in the foamed layer was covered with resin, preventing the standard carrier from directly contacting the particles.

[0025] Therefore, we attempted to decompose the resin covering the surface of the hydrotalcite particles by irradiating the foam layer with ultraviolet light and remove the resin. As a result, at least a portion of the resin coating the hydrotalcite particles on the surface of the foam layer (including the inner walls of the cells opening to the outer surface of the foam layer) was decomposed, and as a result, at least a portion of the hydrotalcite particles could be exposed on the surface of the foam layer (including the inner walls of the cells opening to the outer surface of the foam layer). Furthermore, it was confirmed that the zero-point charge increased significantly in the foamed layer in which hydrotalcite was exposed on the surface. In the electrophotographic roller according to this disclosure, the surface of the foamed layer includes the outer surface of the foamed layer and the inner walls of the cells that open to the outer surface. Next, the inventors conducted the following preliminary experiment to investigate the relationship between the zero-point charge and talc removal ability of an electrophotographic roller.

[0026] First, we prepared electrophotographic rollers with different zero-point charge properties. Then, we removed all the toner from the magenta cartridge of a laser printer (product name: LBP7200C, manufactured by Canon), mixed 135 mg of talc (product code: 020-76007, manufactured by Kishida Chemical Co., Ltd.) with 100 g of the removed toner, and refilled the cartridge with the mixed toner. Furthermore, the toner supply roller attached to the cartridge was replaced with a prepared electrophotographic roller. After the replacement, the toner seal was removed, the cartridge was loaded into a laser printer, and 20 consecutive images with a print density of 1% were printed in a normal temperature and humidity environment (temperature 23±2℃, relative humidity 50±5%).

[0027] Subsequently, during the output of a solid white image, the laser printer was turned off, and the toner on the photoconductor was transferred onto transparent adhesive tape (polyester tape, part number: 5511, manufactured by Nichiban Co., Ltd.) and attached to paper (product name: Vitality, manufactured by Xerox Co., Ltd.). Next to the attached tape, a transparent adhesive tape without the transferred toner was attached as a comparison, and the reflectance (%) of each adhesive tape was measured using a reflectance densitometer (product name: TC-6DS / A, manufactured by Tokyo Denshoku Co., Ltd.). From the reflectance of the comparison tape (without the transferred toner), the toner The value obtained by subtracting the reflectivity of the tape on which the image was copied was defined as the drum cover value (%).

[0028] Next, the toner carrier (developing roller) was removed from the magenta cartridge, and the toner was removed by air blowing the surface of the toner carrier. A portion of the surface of the air-blown toner carrier was cut out, and a platinum deposition sample was prepared by platinum deposition (product name: E-1045, manufactured by Hitachi High-Tech Technology, discharge voltage: 15mA, discharge time: 30 seconds). The atomic composition ratio (Mg / Pt) of magnesium (Mg) contained in talc and deposited platinum (Pt) was determined from the observed sample using energy-dispersive X-ray spectroscopy (EDS, model number: NSS312E, Thermo Fisher). In other words, the amount of talc deposited on the surface of the toner carrier was determined. In this method, the platinum deposition conditions, i.e., the amount of platinum deposited, are kept constant. Therefore, by determining the Mg / Pt value, the amount of Mg (derived from talc) deposited on the surface of the toner carrier can be quantitatively determined.

[0029] The above experiment was repeated for electrophotographic rollers with different zero-point charges. When the zero-point charge of the electrophotographic rollers was plotted against the Mg / Pt values ​​obtained by the above method, the relationship shown in Figure 2A was obtained. As is clear from Figure 2A, we found that the larger the zero-point charge value of the electrophotographic roller (toner supply roller), the lower the Mg / Pt value on the toner carrier, i.e., the amount of talc adhering to the toner carrier. This trend was more pronounced when the zero-point charge value was 40 μC / g or higher.

[0030] Furthermore, as shown in Figure 2B, we confirmed that suppressing the Mg / Pt value on the toner carrier, i.e., the amount of talc adhering to the toner carrier, can suppress fogging on the drum. This disclosure relates to an electrophotographic roller, It comprises a substrate and a foamed layer on the outer surface of the substrate, The foamed layer has a plurality of cells that open to the outer surface, The foamed layer constitutes the outer surface of the electrophotographic roller, This invention relates to an electrophotographic roller in which the zero-point charge of the foamed layer, measured using a standard carrier, is 40 μC / g or higher.

[0031] Furthermore, when an electrophotographic roller is used as a cleaning roller that rotates in contact with the photoreceptor, the talc is collected before it reaches the opposing part between the toner carrier and the photoreceptor, thus suppressing talc fogging on the paper.

[0032] Furthermore, Patent Document 1 discloses that the foam roll according to Patent Document 1 can adsorb and remove oxides such as ozone and nitrogen oxides that adhere to the charging roll by the function of adsorbing acids of hydrotalcite compounds on its circumferential surface (paragraph

[0010] ). Paragraph

[0010] also states that it is preferable for the foam roll to have a resin film mixed with hydrotalcite compounds on its circumferential surface as a specific configuration. Furthermore, paragraphs

[0024] to

[0026] describe the foam structure of a foam roller in which a copolymer nylon resin containing hydrotalcite compound particles in a predetermined proportion is impregnated and cured into a roll-shaped foamed urethane, using Figure 3(b) as follows. That is, a copolymer nylon resin film in which hydrotalcite compound particles are dispersed is formed on the wall surface that forms the foam cell, and the hydrotalcite compound particles are shown to be exposed from the copolymer nylon resin film.

[0033] Here, the present inventors investigated a foamed elastic roller according to Patent Document 1 and found that they were unable to produce a foamed layer with a zero-point charge exceeding 35 μC / g. Furthermore, a foamed roller equipped with a foamed layer having a zero-point charge of 35 μC / g could not adequately remove talc adhering to the surface of the toner carrier. The following are possible reasons why the zero-point charge value of the foam roller is low. In other words, the foam roll fixes hydrotalcite compound particles to the cell walls, etc., with a copolymerized nylon resin film, but the copolymerized nylon resin coating the hydrotalcite compound particles is not actively removed during the manufacturing process. Therefore, the exposure of hydrotalcite compound particles from the copolymerized nylon resin film is considered insufficient to achieve the zero-point charge described in this disclosure.

[0034] (1) Electrophotographic roller An electrophotographic roller according to one aspect of the present disclosure comprises a conductive substrate and a foamed layer on the outer surface of the substrate. An example of an electrophotographic roller is shown in Figure 1. The electrophotographic roller 1 shown in Figure 1 consists of a conductive substrate 3 and a foamed layer 2 provided on its outer surface. Furthermore, the layer structure of the electrophotographic roller 1 is not limited to one consisting only of a substrate 3 and a foam layer 2; a roller with an elastic layer between the substrate 3 and the foam layer 2 is also included. The structure of the electrophotographic roller will be described in detail below.

[0035] <Base> The base 3 functions as a support member and electrode for the electrophotographic roller. The base is made of a conductive material such as metal or alloy such as aluminum, copper alloy, or stainless steel, iron plated with chromium or nickel, or a conductive synthetic resin. For example, the base is a core metal. The base is solid or hollow cylindrical.

[0036] <Foam layer> The foam layer 2 has multiple cells opening to its outer surface. The foam layer 2 constitutes the outer surface of the electrophotographic roller 1. In other words, the foam layer 2 is the outermost layer of the electrophotographic roller 1. The outer surface of the electrophotographic roller 1 is composed of the outer surface of the foam layer 2 and the inner surface of the cells in the foam layer 2 that are opening to the outer surface. The zero-point charge of the foam layer 2 is 40 μC / g or more. "Cell" refers to air bubbles present in the foam layer and air bubbles opening to the outer surface of the foam layer.

[0037] The zero-point charge of the foamed layer 2 is preferably 44 μC / g or more, more preferably 50 μC / g or more, even more preferably 55 μC / g or more, and even more preferably 60 μC / g or more. On the other hand, there is no particular upper limit, but it is preferably 100 μC / g or less, more preferably 80 μC / g or less, and even more preferably 70 μC / g or less. Therefore, the zero-point charge of the foamed layer is preferably in the range of 44 to 100 μC / g, particularly preferably in the range of 50 to 80 μC / g, and even more preferably in the range of 55 to 70 μC / g.

[0038] [particle] One method for increasing the zero-point charge of the foam layer 2 is to include particles in the foam layer, with at least a portion of them exposed on the surface of the foam layer. The particles are not particularly limited, but preferably include a compound containing at least one metal element. The Pauling electronegativity of the metal element is preferably 1.70 or less, more preferably 1.60 or less, even more preferably 1.50 or less, even more preferably 1.40 or less, and particularly preferably 1.35 or less. A lower electronegativity value makes it easier to release electrons (and thus more likely to become positively charged), allowing the zero-point charge of the foam layer to be made more positively large. Therefore, there is no particular lower limit, but for example, it is preferably 0.90 or higher, more preferably 1.00 or higher, even more preferably 1.10 or higher, and 1.20 or higher. It would be even more preferable.

[0039] There are no particular limitations on the metallic elements with a Pauling electronegativity of 1.70 or less. Specifically, for example, it refers to at least one selected from the group consisting of elements from groups 1 to 5, chromium (Cr), manganese (Mn), aluminum (Al), zinc (Zn), cadmium (Cd), and thallium (Tl). From the viewpoint of safety (toxicity), at least one selected from the group consisting of elements from groups 1 to 5, manganese (Mn), aluminum (Al), and zinc (Zn) is preferred, and at least one selected from the group consisting of lithium (Li), manganese (Mn), aluminum (Al), and zinc (Zn) is more preferred.

[0040] When multiple types of particles containing metal elements are added to a foamed layer, or when particles containing multiple metal elements are added to a single type of particle, the weighted average of the Pauling electronegativity values ​​of each individual metal element contained in each particle, based on the atomic ratio of each metal element, should be 1.70 or less. Furthermore, if the zero-point charge of the foamed layer is within the range of 40 μC / g or more, compounds containing metals with a Pauling electronegativity of more than 1.70 may be used in combination with the above-mentioned metal elements.

[0041] Preferably, the foam layer has particles containing metal elements exposed on its surface. This makes it easier to control the zero-point charge of the foam layer within the above range. More specifically, it is preferable that at least a portion of the particles are exposed on the outer surface of the foam layer, and at least a portion of the particles are also exposed on the inner walls of cells opening to the outer surface.

[0042] The following explanation will be given using Figure 11, which is a partial enlargement view of the foamed layer of an electrophotographic roller according to one aspect of this disclosure. The foamed layer 1100 has a plurality of cells 1101 opening on its outer surface. The foamed layer 1100 also contains a binder resin 1105 and a plurality of particles 1107 dispersed in the binder resin 1105. At least a portion of the plurality of particles 1107 are exposed on the outer surface 1103-1 of the foamed layer 1100 and on the inner walls 1103-1 of the cells 1101 opening on the outer surface. In this disclosure, the surface of the foamed layer 1100 includes both the outer surface 1103-1 of the foamed layer 1100 and the inner walls 1103-3 of the cells opening on the outer surface 1103-1. Furthermore, "exposure" of particles means that at least a portion of a single particle 1107 is not covered by the binder resin 1105 and constitutes a part of the surface of the foamed layer.

[0043] With this configuration, the particles 1107 present on the outer surface 1103-1 of the foam layer 1100 can electrostatically adsorb talc, and talc that has entered the interior of the cell 1101 by being scraped off the outer surface 1103-1 of the foam layer 1100 is also adsorbed by the particles 1107 exposed on the inner wall 1103-3 of the cell. As a result, a larger amount of talc can be adsorbed.

[0044] The foamed layer preferably has an open-cell or semi-open-cell structure. In particular, a foamed layer with an open-cell structure allows ultraviolet rays and electron beams to penetrate more easily into the interior of the foamed layer compared to a closed-cell foamed layer, and the decomposition and removal of the resin covering the particle surface occurs over a wider area, thus significantly increasing the adsorption effect of talc.

[0045] The degree of particle exposure from the foam layer can be quantified by X-ray photoelectron spectroscopy (XPS), as described later. Specifically, the total content S1 of metal elements with a Pauling electronegativity of 1.70 or less, as measured by X-ray photoelectron spectroscopy of the outer surface of the foam layer, is 0.4 atomic% or more. It is preferable that it be present, more preferably 0.6 atomic% or more, and even more preferably 1.0 atomic% or more. There is no particular upper limit, but it is preferable that it be 5.0 atomic% or less, more preferably 3.0 atomic% or less, even more preferably 2.0 atomic% or less, and even more preferably 1.6 atomic% or less. For example, S1 is preferably 0.4 to 5.0 atomic%, more preferably 0.6 to 3.0 atomic%, and even more preferably 1.0 to 2.0 atomic%.

[0046] Furthermore, the total content S2 of metal elements with a Pauling electronegativity of 1.70 or less, measured by X-ray photoelectron spectroscopy of the inner wall of the cell opening on the outer surface of the foam layer, is preferably 0.4 atomic% or more, more preferably 0.6 atomic% or more, and even more preferably 1.0 atomic% or more. There is no particular upper limit, but it is preferably 5.0 atomic% or less, more preferably 3.0 atomic% or less, even more preferably 2.0 atomic% or less, and even more preferably 1.5 atomic% or less. For example, S2 is preferably 0.4 to 5.0 atomic%, more preferably 0.6 to 3.0 atomic%, and even more preferably 1.0 to 2.0 atomic%.

[0047] To check for particle exposure on the outer surface of the foam layer, the measurement is performed by focusing X-rays on the outer surface of the foam layer. When measuring the inner wall of a cell, the measurement is performed by focusing X-rays onto the cell wall through the cell's opening. By measuring with X-rays narrower than the cell opening, the inner wall of the cell can be selectively measured. If the cell aperture size is smaller than the width of the X-ray beam, the measurement can be performed by polishing the outer surface by 500 μm and focusing the X-ray beam onto the non-polished area. The proportion of this content can be controlled by factors such as the amount of metal elements added and the degree to which particles are exposed from the cell, such as the intensity of ultraviolet irradiation.

[0048] On the other hand, in the case of an electrophotographic roller in which the particles are only physically attached to the foamed layer, when the electrophotographic roller is used only slightly, the particles are easily peeled off from the foamed layer, and it is difficult to obtain the effect of substantially adsorbing talc. Therefore, in order to control the zero-point charge within the above range, it is preferable to expose the particles on the inner wall of the cell. It is also preferable to bury a part of the particles in the foamed layer or to chemically bond (such as covalent bond) the particles to the foamed layer.

[0049] Examples of the compound containing a metal element having an electronegativity of 1.70 or less in polling include hydrotalcite compounds represented by the following formula (1). Mg (1-x) Al x (OH)2(CO3) x / 2 ·mH2O ···(1) In formula (1), x satisfies 0.00 < x ≦ 0.50 (x is more preferably 0.10 to 0.40, still more preferably 0.20 to 0.30), and m is a positive number (more preferably 0.2 to 1.0, still more preferably 0.4 to 0.7).

[0050] In addition, metal oxides such as MgO, ZnO, Eu2O3, Y2O3, CdO, CoO, NiO, HgO, CuO, Al2O3, and metal composite oxides such as MgAl2O4, ZnAl2O4 can be mentioned. Among them, since the positive charge property of the particles is high, it is preferable that the particles contain at least one selected from the group consisting of magnesium oxide and hydrotalcite compounds, and it is more preferable to contain magnesium oxide.

[0051] There is no particular limitation on the average particle diameter of the particles (the additive average value of the Feret diameters of the particles including the unexposed part). . However, in order to adsorb and hold talc by electrostatic attraction, it preferably has a size of a certain level or more. Specifically, 100 nm or more is preferable. In addition, in order to make it difficult for the particles to fall off from the foamed layer during the use of the electrophotographic roller, it is preferable to have a particle diameter of a certain level or less. Specifically, 50 μm or less is preferable. The average particle size of the particles is more preferably 0.3 to 25.0 μm, and even more preferably 1.0 to 3.0 μm.

[0052] The average particle size is determined by first heating the foam layer to 500°C to decompose the binder. Then, the residue is collected and images of the particles are taken using a known microscope or similar device. The average particle size is then determined by measuring the Ferret diameter in both the vertical and parallel directions of the image.

[0053] The proportion of the above-mentioned particles in the foamed layer is not particularly limited, as long as it is sufficient to control the zero-point charge of the foamed layer within the above range. The proportion of the particles in the foamed layer is preferably 1 to 20 parts by mass, more preferably 2 to 15 parts by mass, and even more preferably 3 to 10 parts by mass, per 100 parts by mass of the resin (binder resin) contained in the foamed layer.

[0054] [resin] The foamed layer preferably has a foaming binder resin. For example, the foamed layer preferably has particles dispersed in the binder resin. There are no particular restrictions on the resin of the foamed layer, and it can be appropriately selected and used from known resins. Examples include epoxy resins, urea resins, ester resins, amide resins, imide resins, amide-imide resins, phenolic resins, vinyl resins, silicone resins, and fluororesins. The following rubber materials are also suitably used as the resin for the foam layer. Examples of rubber materials include ethylene-propylene-diene copolymer rubber, acrylonitrile-butadiene rubber, chloroprene rubber, natural rubber, isoprene rubber, styrene-butadiene rubber, silicone rubber, epichlorohydrin rubber, polyurethane, and the like. Preferably, polyurethane and acrylonitrile-butadiene rubber are used. Among these, polyurethane is preferred because it has electron-donating nitrogen elements in its structure and is easily positively charged. In other words, it is preferable that the foam layer contains polyurethane as a binder resin. Furthermore, polyurethane is preferred because it is easily decomposed by electron beam or ultraviolet irradiation, and the particles can be easily exposed (the resin thinly covering the particle surface can be decomposed and removed). Polyurethanes can be made, for example, from the reaction products of known polyols and isocyanates.

[0055] There are no particular restrictions on the polyol used; various polyols known as raw materials for polyurethane can be appropriately selected and used. For example, polyols such as polyether polyols and polyester polyols, which are commonly used in the manufacture of flexible polyurethane foam, can be appropriately selected and used. One type of polyol may be used, or two or more types may be used in combination. Of the polyols mentioned above, polyether polyols are suitable for producing flexible, highly elastic polyurethane foam with excellent moisture and heat resistance. For example, polyethylene propylene ether triol is preferred.

[0056] There are no particular restrictions on the isocyanate used; various isocyanates conventionally known as raw materials for polyurethanes can be appropriately selected and used. For example, 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), tolidine diisocyanate (TODI), naphthylene diisocyanate (NDI), xylylene diisocyanate (XDI), 4,4'-diphenylmethane diisocyanate (MDI), carbodiimide-modified MDI, polymethylene polyphenyl isocyanate, Polymeric isocyanates may be used individually or in combination of two or more. Furthermore, isocyanate-terminated prepolymers obtained by reacting an isocyanate with one or more known active hydrogen compounds can also be used as isocyanates.

[0057] To facilitate the decomposition and removal of the resin covering the particle surface by electron beam or ultraviolet irradiation, aromatic isocyanates having double bonds are preferred over aliphatic isocyanates. The isocyanate preferably contains at least one selected from the group consisting of 2,4-tolylene diisocyanate (2,4-TDI), 2,6-tolylene diisocyanate (2,6-TDI), and 4,4'-diphenylmethane diisocyanate (MDI).

[0058] From the viewpoint of decomposing and removing the resin by electron beam or ultraviolet irradiation, it is preferable that the urethane resin contains a certain amount or more of aromatic isocyanate. Specifically, the ratio (molar ratio) of isocyanate groups to hydroxyl groups in the polyol is preferably 0.9 or more, and more preferably 0.95 or more.

[0059] [others] Catalysts, foaming agents, foam stabilizers, and other auxiliary agents may be used as needed. There are no particular restrictions on the catalyst, and various known catalysts can be appropriately selected and used. For example, amine catalysts (triethylenediamine, bis(dimethylaminoethyl) ether, N,N,N',N'-tetramethylhexanediamine, 1,8-diazabicyclo(5,4,0)undecene-7, 1,5-diazabicyclo(4,3,0)nonene-5, 1,2-dimethylimidazole, N-ethylmorpholine, N-methylmorpholine, etc.), organometallic catalysts (tin octylate, tin oleate, dibutyltin dilaurate, dibutyltin diacetate, tetra-i-propoxytitanium, tetra-n-butoxytitanium, tetrakis(2-ethylhexyloxy)titanium, etc.), and acid salt catalysts (carboxylates, formates, octylates, borates, etc.) with reduced initial activity of the amine and organometallic catalysts can be used. One catalyst may be used, or two or more may be used in combination.

[0060] There are no particular restrictions on the blowing agent used to foam the resin of the foamed layer; various known blowing agents can be appropriately selected and used. In particular, when polyurethane or polyurea binder resins are used, water is preferably used as a blowing agent because it reacts with isocyanate to generate carbon dioxide. Other blowing agents may also be used in combination with water.

[0061] There are no particular restrictions on the foam stabilizer; any known foam stabilizer can be appropriately selected and used. Other auxiliary agents may be used as needed, to the extent that they do not interfere with the effects of this disclosure, including crosslinking agents, vulcanizing agents, vulcanization accelerators, vulcanization aids, flame retardants, colorants, ultraviolet absorbers, antioxidants, conductive agents, etc. As conductive agents, electronic conductive agents such as carbon black or ionic conductive agents can be used.

[0062] Another method for achieving the zero-point charge of the foamed layer within the above range is to use an organic charge imparting agent. Specifically, by using an acrylic resin having a quaternary ammonium base with high positive charge properties, a foamed layer with a zero-point charge of 40 μC / g or more can be obtained. Examples of quaternary ammonium bases include, for example, an ammonium group (preferably -N(CH3)2(C8H) 17 ) + ) are some examples. Examples of acrylic resins having such quaternary ammonium bases include polymers of methyl methacrylate and dimethylaminoethyloctyl bromide methacrylate. When polyurethane is used as a binder resin, for example, the acrylic resin is more easily exposed on the outer surface of the foam layer and on the cell surface due to the polarity relationship between the two. As a result, it becomes easier to achieve a zero-point charge of 40 μC / g or more in the foam layer. This method using such an acrylic resin may be used independently of or in combination with the method using a compound containing a metal element with an electronegativity of 1.70 or less, as described above.

[0063] Incidentally, acrylic resins containing amino groups (-NR1R2; R1 and R2, for example, represent alkyl groups) in their molecules often have high compatibility with polyurethane. Therefore, when polyurethane is used as a binder for a foamed layer, the acrylic resin is less likely to be exposed on the outer surface of the foamed layer and on the surface of the cells. Consequently, when using such acrylic resins, it is difficult to obtain a foamed layer with a zero-point charge of 40 μC / g or higher.

[0064] (Method for forming a foamed layer) There are no particular restrictions on the foaming method for the foamed layer. Any method can be used, such as using a foaming agent or incorporating bubbles by mechanical stirring. The foaming ratio can be determined as appropriate and is not particularly restricted.

[0065] For example, by mixing materials 1 to 5 below and reacting them while causing foaming, a foamed layer for an electrophotographic roller can be obtained. 1. As a material for forming the binder resin, • Polyether polyols, polyester polyols, etc. · Isocyanate 2. A compound comprising at least one metal, wherein the metal has a Pauling electronegativity of 1 Particles with a value of 0.7 or less 3. Catalyst 4. Foam stabilizer 5. Foaming agent

[0066] There are no particular restrictions on the method of joining the substrate and the foam layer. Methods include pre-positioning the substrate inside a mold and then casting and curing the raw material mixture as described above, or pre-forming the raw material mixture into a predetermined shape for the foam layer and then bonding it to the substrate. In either method, an adhesive layer can be provided between the substrate and the foam layer as needed. Known materials such as adhesives or hot-melt sheets can be used for this adhesive layer.

[0067] In the case of casting curing, a mold release agent may be pre-applied to the inner wall of the mold. Known mold release agents can be used. Examples include water-based mold release agents containing olefin and silicone components, and mold release agents in which a fluorine component is dissolved in a fluorine-based solvent.

[0068] There are no particular restrictions on the method for forming the shape of the foam layer. For example, in addition to the method of pouring into a mold of a predetermined shape as described above, other methods include cutting a block of foam (so-called slab foam) to a predetermined size and then polishing it into a cylindrical shape, or molding it to a predetermined size using an extruder.

[0069] There are no particular restrictions on the method used to expose the particles contained in the resin from the inner wall of the cell. Examples include polishing the surface of the foam layer, irradiating with ultraviolet light using a low-pressure mercury lamp, and irradiating with an electron beam. Among these, irradiation with ultraviolet light or an electron beam does not apply mechanical shear force to the foam layer, so it can decompose the resin without causing the particles to fall out of the foam layer, and effectively expose the particles. The amount of ultraviolet light, etc., can be controlled within the range where the above-mentioned zero-point charge can be obtained, and is not particularly limited. For example, the sensitivity of a 254nm sensor is preferably 1000 to 10000 mJ / cm². 2 , more preferably 2000~6000 mJ / cm² 2 The irradiation should be performed to the extent that it reaches the desired level. The irradiation time is, for example, preferably 1 to 60 minutes, more preferably 2 to 10 minutes.

[0070] The type of resin in the foam layer can be identified by known methods such as pyrolysis GC / MS, FT-IR, and 13C-NMR. The types of metal elements contained in the particles and their composition ratios can be confirmed by known energy-dispersive X-ray analysis (EDS) and X-ray diffraction (XRD). EDS analysis can obtain the types of metal elements and their composition ratios of the particles. Furthermore, if the particles are crystalline, the foam layer can be heated and decomposed in a nitrogen atmosphere, and the detailed composition formula can be obtained by XRD of the remaining particle powder.

[0071] The degree of particle exposure can be confirmed by known methods such as XPS. Since XPS provides information on the outermost surface (a few nanometers) of the irradiated region, it is possible to qualitatively and quantitatively determine the metallic elements contained in the exposed particles.

[0072] (2) Process cartridge This disclosure provides a process cartridge that is detachably configured to be attached to the main body of an electrophotographic image forming apparatus, and comprises an electrophotographic roller. Preferably, the process cartridge comprises a photoreceptor and a toner carrier that transports toner to the surface of the photoreceptor. Preferably, the electrophotographic roller is at least one of a toner supply roller that supplies toner to the surface of the toner carrier and a cleaning roller that cleans the photoreceptor after transfer. A process cartridge according to one aspect of this disclosure will be described in detail with reference to the figures, but this disclosure is not limited to these. Figures 3 and 4 are schematic diagrams showing an example of a process cartridge in which an electrophotographic roller according to one aspect of this disclosure is used as a toner supply roller 8. Figure 5 is a schematic diagram showing an example of a process cartridge in which an electrophotographic roller according to one aspect of this disclosure is used as a cleaning roller 13.

[0073] The process cartridge shown in Figure 3 comprises a cleaning blade 5, a charging roller 6, a toner carrier 7, a toner supply roller 8, toner 9, a toner regulating member 10, and a photoreceptor 11, and is configured to be detachable from the main body of the electrophotographic device. The photoreceptor 11 is charged by the charging roller 6 and rotated in the direction of arrow R1. The toner supply roller 8 is in contact with the toner carrier 7 and rotates, supplying toner to the surface of the toner carrier 7. The toner regulating member 10 is in contact with the toner carrier 7 and regulates the amount of toner on the surface of the toner carrier 7. The toner carrier 7 rotates in the direction of arrow R2, transporting toner to the developing area where the toner carrier 7 and the photoreceptor 11 face each other.

[0074] In this embodiment, the process cartridge employs a so-called contact development method in which the toner carrier 7 is positioned in contact with the photoreceptor 11. Toner remaining on the photoreceptor 11 after being transferred to paper is scraped off by the cleaning blade 5 and stored in the cleaner container. In this embodiment, by using the electrophotographic roller as the toner supply roller 8, talc adhering to the toner carrier 7 can be removed by the toner supply roller 8. Figure 4 shows a process cartridge having a charging roller brush 12 that rotates in contact with a charging roller.

[0075] The process cartridge shown in Figure 5 has a cleaning roller 13 that rotates in contact with the photoreceptor, and toner remaining on the photoreceptor 11 after being transferred to paper is scraped off by the cleaning roller 13. The electrophotographic roller described above is used as the cleaning roller 13. Therefore, the talc on the photoreceptor 11 can be removed before it reaches the area where the toner carrier 7 and the photoreceptor 11 meet.

[0076] (3) Electrophotographic image forming apparatus This disclosure provides an electrophotographic image forming apparatus comprising the above-mentioned electrophotographic roller. An electrophotographic image forming apparatus includes, for example, a photoreceptor, a toner carrier for transporting toner to the surface of the photoreceptor, a toner supply roller for supplying toner to the surface of the toner carrier, and a cleaning roller for cleaning the photoreceptor. Preferably, the electrophotographic roller is at least one of the toner supply roller and the cleaning roller. [Examples]

[0077] The present disclosure will be explained below with reference to examples and comparative examples, but the present disclosure is not limited in any way by these examples. Unless otherwise specified, all "parts" in the examples and comparative examples refer to mass.

[0078] (Example 1) As shown in Figures 6A to 6C, a mold consisting of a cylindrical member 22 with an inner diameter of 11 mm coated with a release agent on its inner surface, an upper die member 23, and a lower die member 21, and a core metal 24 made of stainless steel (SUS304) with an outer diameter of 4 mm as the base were prepared, and all were preheated to 70°C. A cylindrical member 22 was attached to the lower insert member 21, and a core metal 24 was placed therein (Figure 6A). Materials (A) to (G) below were pre-mixed to form liquid B, and material (H) was designated as liquid A. The urethane rubber composition 25 obtained by mixing liquid A and liquid B was injected through the gap between the cylindrical member and the core metal 24 (Figure 6B). At that time, liquid A and liquid B were mixed using a mixing head equipped with an agitation rotor 37 and a mixing chamber 36, as shown in Figures 10A to 10D. The mixing of liquid A and liquid B was performed immediately before injection. After injecting the urethane rubber composition 25, an upper insert member 23 was attached to the upper end surface of the cylindrical member 22, and the core metal 24 was held concentrically with the cylindrical member 22 by the upper insert member 23 and the lower insert member 22 (Figure 6C). Here, the stirring rotor 37 comprises a rotor body 37-1 and a tip rod 37-3, as shown in Figures 10B to 10D. Multiple stirring blades 37-1a are provided on the side of the rotor body 37-1. Stirring blades 37-1b are also provided on the tapered portion of the rotor body 37-1, and stirring blades 37-3a are also provided on the side of the tip rod 37-3. Figure 10C is a side view of the stirring rotor shown in Figure 10B when rotated 90 degrees around the rotation axis R, and Figure 10D is a schematic view of the stirring rotor shown in Figure 10B when viewed from vertically below.

[0079] (A) Polyol (polyethylene propylene ether triol with a number-average molecular weight of 3100, trade name: Actcol EP-550N, manufactured by Mitsui Chemicals): 100.0 parts (B) Conductive agent (product name: Sankonol PEO-20R, manufactured by Sanko Chemical Industry Co., Ltd.): 1.0 part (C) Silicone foam stabilizer (product name: SRX274C, manufactured by Toray Dow Corning): 1.0 part (D) Tertiary amine catalyst A (bis(2-dimethylaminoethyl) ether and dipropylene Mixture for recall, trade name: TOYOCAT-ET, manufactured by Tosoh Corporation: 0.3 parts (E) Tertiary amine catalyst B (mixture of triethylenediamine and dipropylene glycol, trade name: TEDA-L33, manufactured by Tosoh Corporation): 0.2 parts (F) Particles (magnesium oxide, trade name: Pyroxima 5301, manufactured by Kyowa Chemical Industry Co., Ltd., average particle diameter 2 μm): 5 parts (G) Foaming agent (water): 1.4 parts (H) Isocyanate mixture (NCO% = 45, containing 20% MDI, trade name: Cosmonate TM20, manufactured by Mitsui Chemicals, Inc.): 24.4 parts

[0080] Subsequently, in a state where the cylindrical member 22, the upper piece member 23, and the lower piece member 21 were integrated, the heated state at 80 °C was maintained for 10 minutes to foam and cure the urethane rubber composition 25. After cooling to about 50 °C, the upper piece member 23 and the lower piece member 21 were removed, and the core metal 24 with a foam layer formed on the outer peripheral surface was demolded from the cylindrical member, and a foamed roller was obtained.

[0081] Next, surface treatment by ultraviolet rays was performed on the foam layer of the foamed roller to obtain the electrophotographic roller Y-1 according to Example 1. The surface treatment was performed by uniformly irradiating ultraviolet rays on the outer surface of the foamed roller while rotating it using a low-pressure mercury lamp (trade name: GLQ500US / 11, manufactured by Harrison Toshiba Lighting Corporation). The light amount of ultraviolet rays was 4000 mJ / cm at the sensitivity of the 254 nm sensor 2 , and the treatment time was 5 minutes.

[0082] Elemental analysis of the outer surface of the foam layer of the electrophotographic roller Y-1 and the inner wall of the cell opened on the outer surface was performed by XPS (product name: VersaProbe II, manufactured by ULVAC-PHI, Inc.) to measure the amount of magnesium. The measurement conditions of XPS are as follows. X-ray source: monochromatic Al Kα, X-ray Setting: 100 μmφ (25 W (15 KV)), photoelectron extraction angle: 45 degrees, neutralization condition: combined use of neutral gun and ion gun, analysis area: 100 × 100 μm 2 , Pass Energy: 23.5 eV, step size: 0.1 eV. For quantitative analysis of each element, the atomic percentages were determined using the C1S (BE 280-294 eV), N1S (BE 392-406 eV), O1S (BE 526-538 eV), Mg2P (BE 44-60 eV), and Al2P (BE 68-84 eV) peaks. In XPS analysis, the atomic percentage of metallic elements with a Pauling electronegativity of 1.70 or less is calculated, assuming the total amount of all detected elements is 100 atomic%. Furthermore, measurements of the cell's inner wall were performed by focusing X-rays onto a portion of the cell's inner wall through the cell's opening. The results are shown in Table 3. In Table 3, "S1" represents the amount of metallic elements based on measurements at the outer surface of the foamed layer, and "S2" represents the amount of metallic elements based on measurements at the inner wall of the cell opening at the outer surface of the foamed layer.

[0083] [Measuring Zero Point Charge] Step (i): Prepare the standard carriers (P-01, P-02, N-02, and N-01) distributed by the Image Science Society of Japan as the first to fourth reference powders, and N-01T, also distributed by the Image Science Society of Japan, as the toner for measuring the standard carriers.

[0084] The charge levels of the first to fourth reference powders are determined relative to the standard carrier measurement toner N-01T using the blow-off method. For the blow-off method, first, 9.5g of standard carrier and 0.5g of standard carrier measurement toner N-01T are placed in a 50mL polyethylene container and left to stand for 12 hours in an environment with a temperature of 23±2℃ and a relative humidity of 50±5%. Next, the container is covered and shaken for 5 minutes using an arm-type shaker mixer (model: YS-8D, manufactured by Yayoi Corporation) at an angle of 30 degrees and a shaking speed of 150 times / min. 0.3g of the mixture is placed on a metal mesh with a mesh size of 26μm, and toner N-01T is aspirated at 2MPa for 2 minutes using a dust collector (model: VF-5N, manufactured by Amano Corporation). At this time, the charge Q (μC) of the carriers remaining on the mesh is measured using a digital electrometer (model: 6514, manufactured by KEITHLEY). Furthermore, the charge amount verification value Q / M (μC / g) is calculated, with M (g) being the mass of the attracted toner.

[0085] The standard carrier charge values ​​obtained by the blow-off method were -18.1 (μC / g), 18.8 (μC / g), and 26.5 (μC / g) for P-02, P-01, N-02, and N-01, respectively. The result was 44.7 (μC / g).

[0086] Step (ii): The electrophotographic roller to be measured is heated to a temperature of 23.5°C and a relative humidity of 5°C. Leave it undisturbed in a 0% environment for 24 hours.

[0087] Step (iii): Under the same conditions as in step (ii), as shown in Figure 7, the electrophotographic roller 1 is placed so that its axis of rotation is horizontal, and 5g of standard carrier (P-01) is allowed to flow down from a funnel 31 having legs with an inner diameter of 1.5 mm over 12 seconds, such that point A (see Figure 8B) on the circumferential surface of the electrophotographic roller becomes the center of fall. Point A will be described later.

[0088] The entire amount of the standard carrier (P-01) that was allowed to flow down was collected in a metal collection container 32 placed below the electrophotographic roller, and the charge amount Q (μC) of the collected standard carrier (P-01) was measured using a cascade-type surface charge measuring device (model number: TS-100, manufactured by Kyocera Chemical Corporation). An insulating plate 33 is provided at the bottom of the collection container 32.

[0089] Furthermore, the amount of standard carrier (P-01) recovered, W (g), was determined from the difference in mass of the recovery container 32 before and after the recovery of the standard carrier (P-01). The value obtained by dividing the charge amount Q (μC) of the standard carrier (P-01) by the recovered amount W (g) (Q(μC) / W(g)) is defined as the triboelectric charge amount when using the standard carrier (P-01).

[0090] As shown in Figure 8B, point A is defined as follows: The electrophotographic roller is placed so that its axis of rotation is horizontal, and the electrophotographic roller is viewed from above in a plan view (Figure 8B). A line segment L is drawn that passes through the midpoint C in the direction along the axis of rotation of the electrophotographic roller and is perpendicular to the direction along the axis of rotation. In the plan view as shown in Figure 8B, the intersections of the line segment L and the ends of the electrophotographic roller are defined as points c1 and c2. At this time, point A is located 1 mm from point c1 toward point c2 on the line segment L in the plan view, and is on the outer surface of the electrophotographic roller. When viewing the cross-section of the electrophotographic roller along the line segment L, point A is represented as shown in Figure 8A (for convenience, the line segment L is shown as the center of the roller in Figure 8A). Furthermore, adjust the height of the funnel 31 so that the distance (vertical distance) between the tip of the leg of the funnel 31 and point A is 15 mm.

[0091] Step (iv): After rotating the electrophotographic roller 90° counterclockwise, the amount of triboelectric charge on the standard carrier (P-02) is calculated in the same manner as in step (iii), except that the standard carrier (P-02) is used.

[0092] Step (v): After further rotating the electrophotographic roller 90° counterclockwise, the amount of triboelectric charge on the standard carrier (N-02) is calculated in the same manner as in step (iii), except that the standard carrier (N-02) is used.

[0093] Step (vi): After further rotating the electrophotographic roller 90° counterclockwise, the amount of triboelectric charge on the standard carrier (N-01) is calculated in the same manner as in step (iii), except that the standard carrier (N-01) is used.

[0094] Step (vii): As shown in Figure 9, in an XY plane graph, the charge amount verification value of the standard carrier (P-01) obtained in step (i) is plotted as the value on the X axis, and the triboelectric charge amount obtained in step (iii) is plotted as the value on the Y axis.

[0095] Similarly, for standard carriers P-02, N-02, and N-01, the respective charge values ​​obtained in process (i) are plotted on the X-axis, and the triboelectric charge values ​​of each standard carrier obtained in processes (iv) to (vi) are plotted on the Y-axis, and these are plotted on an XY plane graph.

[0096] For the four plots described above, a regression line is drawn using the least squares method, and the value at the intersection of this regression line with the X-axis (the distance from the origin of the XY plane to this intersection) is defined as the zero-point charge of the electrophotographic roller. Since the relative charge sequence with respect to the standard carrier does not change even when the temperature and humidity environment changes, the zero-point charge also does not change significantly.

[0097] Furthermore, when measuring the zero-point charge of an electrophotographic roller with toner or other substances attached, the attached substances should be removed before measurement. The following methods can be used to remove the attached substances.

[0098] First, the electrophotographic roller is air-blown to remove toner from inside the foam structure. Next, the roller is ultrasonically cleaned in water using an ultrasonic cleaner and dried in a 60°C oven for 12 hours. After that, the roller is observed using a scanning electron microscope (SEM) to confirm that all deposits have been completely removed. If all deposits are not completely removed, the ultrasonic cleaning and drying process is repeated.

[0099] [Image evaluation of talc-covered subjects] The electrophotographic roller was used as the toner supply roller for evaluation of talc paper fouling. First, the electrostatic roller brush was removed from the cartridge of a laser printer (product name: HP LaserJet Pro M102w Printer, manufactured by Hewlett-Packard), and the printer was modified to accommodate a toner supply roller. The laser printer, with the toner supply roller installed, was placed in a high-temperature, high-humidity environment (temperature: 32.5°C, relative humidity: 80%) and left undisturbed for more than 12 hours. Next, a black image with a print density of 1% was printed 1000 times consecutively onto a predetermined number of sheets of talc-containing paper (product name: Century Star paper, manufactured by Century). At this time, the reflectance (denoted as R1(%)) at a position 5 mm from the edge of the 1000th image was measured using a reflectance densitometer (product name: TC-6DS / A, manufactured by Tokyo Denshoku Co., Ltd.). In addition, as a comparison of reflectance, the reflectance of unprinted paper (denoted as R2(%)) was measured in the same way, and the value obtained by subtracting R1(%) from R2(%) was defined as the talc paper cover value (%).

[0100] Subsequently, while the solid white image was being output, the power to the color laser printer was turned off and the process cartridge was removed. Next, the charge amount Q / M per unit mass of toner on the toner carrier was measured by the suction method. For the measurement of Q / M by the suction method, a measuring container with cylindrical filter paper (product name: Cylindrical Filter Paper No. 86R, manufactured by Advantec Co., Ltd.) was used to measure the surface of the toner carrier. A metal suction port conforming to the shape of the toner carrier is attached, and the suction pressure is adjusted to uniformly and completely aspirate the toner from the surface of the toner carrier immediately after image formation. The charge Q (mC) of the aspirated toner is then measured using a digital electrometer (model: 8252, manufactured by ADC Corporation), and the ratio Q / M (mC / kg) is calculated, with the mass being M (kg).

[0101] (Examples 2-9) (F) Except for changing the type and amount of particles as shown in Table 1, electrophotographic rollers Y-2 to Y-9 according to Examples 2 to 9 were prepared in the same manner as in Example 1 and evaluated in the same manner as in Example 1.

[0102] (Example 10) Except for (A) changing the type of polyol to (I) a polyester polyol with a number average molecular weight of 1000 (product name: Kuraray Polyol P-1020, manufactured by Kuraray Co., Ltd.) and (H) changing the amount of isocyanate admixture to 31.7 parts, the same procedure as in Example 1 was followed to produce an electronic image of Example 8. A true roller Y-10 was fabricated and evaluated in the same manner as in Example 1.

[0103] (Example 11) An electrophotographic roller Y-11 according to Example 11 was fabricated in the same manner as in Example 1, except that the surface treatment time with ultraviolet light was changed as shown in Table 1. Elemental analysis of the inner wall of the cell of the electrophotographic roller by XPS revealed a magnesium content of 0.4 atomic%. Furthermore, perform the evaluation in the same manner as in Example 1.

[0104] (Example 12) Under an argon atmosphere, 22.9 g of methyl methacrylate, 20.0 g of dimethylaminoethyl octyl bromide salt of methacrylate, and 1.0 g of benzoyl peroxide were dissolved in 85 g of ethanol and reacted at 80°C for 4 hours. Subsequently, the mixture was heated in an open system to evaporate the ethanol and obtain a random copolymer. (F) Two parts of the random copolymer were added instead of the particles, and it was confirmed that it dissolved uniformly in solution B. Thereafter, an electrophotographic roller Y-12 according to Example 12 was prepared in the same manner as in Example 1, except that surface treatment with ultraviolet light was not performed, and it was evaluated in the same manner as in Example 1.

[0105] Table 1 shows the formulations for each electrophotographic roller obtained. [Table 1]

[0106] (Example 13) (Preparation of unvulcanized rubber composition) The unvulcanized rubber described below was mixed with a vulcanization aid and particles, and then kneaded for 7 minutes at a rotor speed of 30 rpm using a 7-liter sealed kneader (product name: WDS7-30: manufactured by Nippon Spindle Manufacturing Co., Ltd. (formerly Moriyama Co., Ltd.)).

[0107] <Unvulcanized rubber> (J) Acrylonitrile butadiene rubber (Nipol DN401LL, manufactured by Nippon Zeon Co., Ltd.): 68 parts (K) Epichlorohydrin / ethylene oxide / allyl glycidyl ether terpolymer containing 56.7% by mass of ethylene oxide (EPION301, manufactured by Osaka Soda Co., Ltd.): 22 parts (L) Epichlorohydrin / ethylene oxide / allyl glycidyl ether terpolymer containing 37.2% by mass of ethylene oxide (epichromate CG102, manufactured by Osaka Soda Co., Ltd.): 10 parts

[0108] <Vulcanization aid> (M) Zinc stearate (zinc stearate, manufactured by NOF Corporation): 3.0 parts (N) Stearic acid (Camellia stearate, manufactured by NOF Corporation): 1.0 part

[0109] <Particle> (F) Magnesium oxide (product name: Pyroxma 5301, manufactured by Kyowa Chemical Industry Co., Ltd.): 5 parts

[0110] After kneading, a foaming agent, vulcanizing agent, and vulcanization accelerator were added, and the mixture was kneaded and dispersed for 15 minutes using a 12-inch open roll (Kansai Roll Co., Ltd.) while cooling to maintain the temperature of the unvulcanized rubber composition below 80°C. Finally, the mixture was shaped into a ribbon and removed to prepare the unvulcanized rubber composition for conductive foam formation.

[0111] <Sulfurizing agent> (O) Sulfur (Sulfax PMC, manufactured by Tsurumi Chemical Co., Ltd.): 3.0 parts

[0112] <Vulcanization promoter> (P) Tetraethyl thiuram disulfide (Noxellar TET-G, manufactured by Ouchi Shinko Chemical Co., Ltd.): 2.0 parts (Q) Dibenzothiazyl disulfide (Noxellar DM-P, manufactured by Ouchi Shinko Chemical Co., Ltd.): 1.5 parts

[0113] <Foaming agent> (R) 4,4'-oxybis(benzenesulfonylhydrazide) OBSH (Neocervon N#1000M, manufactured by Eiwa Kasei Kogyo Co., Ltd.) with a median diameter of 5.0 μm: 2.0 parts (S) 0.5 parts of OBSH (NeoCelbon N#1000S, manufactured by Eiwa Kasei Kogyo Co., Ltd.) with a median diameter of 16.0 μm

[0114] (Fabrication of rollers for electrophotography) The unvulcanized rubber composition for the ribbon-shaped conductive foam was extruded into a tube shape using an extruder (60 mm vented rubber extruder, manufactured by Mitsuba Seisakusho Co., Ltd.). Then, a rubber tube was produced by vulcanization and foaming using a vulcanization apparatus (manufactured by Micro Denshi Co., Ltd.) including a 3.0 kW microwave vulcanization device.

[0115] The microwave vulcanization apparatus has a frequency of 2450±50MHz and an output of 0.6kW, and the furnace is... The temperature was set to 180°C. After vulcanization and foaming in the microwave vulcanizing apparatus, further vulcanization and foaming were performed in a hot air vulcanizing apparatus with the furnace temperature set to 200°C. After vulcanization and foaming, the outer diameter of the tube was approximately 14.0 mm and the inner diameter was approximately 3.0 mm. The time required to pass through the microwave vulcanization unit was approximately 2 minutes, the time required to pass through the hot air vulcanization unit was approximately 3 minutes, and the time required to pass through the take-up machine was approximately 30 seconds.

[0116] After vulcanization and foaming, the rubber tube was cut using a fixed-length cutting machine, a shaft core with an outer diameter of 4 mm was pressed into the rubber tube, and both ends were cut to obtain a roller having a rubber layer with a length of 220 mm. The outer surface of the roller was polished at a rotational speed of 1800 rpm and a feed rate of 800 mm / min so that the outer diameter was 11 mm. Next, the foamed layer of the foamed roller was surface-treated with ultraviolet light under the same conditions as in Example 1 to produce the electrophotographic roller Z-1 according to Example 13. Furthermore, the electrophotographic roller Z-1 according to Example 13 was evaluated in the same manner as in Example 1.

[0117] (Examples 14-16) (F) Except for changing the particle types as shown in Table 2, electrophotographic rollers Z-2 to Z-4 according to Examples 14 to 16 were manufactured in the same manner as in Example 13 and evaluated in the same manner as in Example 1. [Table 2]

[0118] (Comparative Example 1) (F) An electrophotographic roller X-1 was prepared in the same manner as in Example 1, except that it was formulated without adding particles, and was evaluated in the same manner as in Example 1.

[0119] (Comparative Example 2) An electrophotographic roller X-2 was fabricated in the same manner as in Example 1, except that surface treatment with ultraviolet light was not performed. Elemental analysis of the inner wall of the electrophotographic roller cell by XPS revealed a magnesium content of 0.2 atomic%. Further evaluation was performed in the same manner as in Example 1.

[0120] (Comparative Example 3) (F) An electrophotographic roller X-3 was fabricated in the same manner as in Example 1, except that the particle type was changed to silica (MSN-002, manufactured by Teika Co., Ltd.), and evaluated in the same manner as in Example 1.

[0121] (Comparative Example 4) An electrophotographic roller X-4 was fabricated in the same manner as in Example 14, except that surface treatment with ultraviolet light was not performed, and it was evaluated in the same manner as in Example 1.

[0122] (Comparative Example 5) 100 parts heated methanol, 3 parts nylon (Tresin EF-30T, manufactured by Teikoku Chemical Industries Co., Ltd.), and hydrotalcite compounds (Mg 0.68 Al 0.32 (OH)2(CO3) 0.16 A nylon solution was prepared by mixing 0.15 parts of 0.57H2O (product name: Kyoward 500, manufactured by Kyowa Chemical Industry Co., Ltd.) until the nylon was completely dissolved. The nylon solution described above was spray-coated onto the roller of Comparative Example 1 while it was rotating, and the roller was dried at 120°C for 30 minutes to produce the electrophotographic roller X-5 according to Comparative Example 5. Elemental analysis of the inner wall of the cell of the electrophotographic roller by XPS revealed that the magnesium content was 0.1 atomic% and the aluminum content was 0.0 atomic%. Furthermore, the electrophotographic roller X-5 was evaluated in the same manner as in Example 1.

[0123] (Example 17) The electrophotographic roller X-5 of Comparative Example 5 was subjected to a surface treatment with ultraviolet light for 5 minutes in the same manner as in Example 1 to produce the electrophotographic roller Y-13 according to Example 17. Elemental analysis of the inner wall of the cell of the electrophotographic roller by XPS revealed that the magnesium content was 0.6 atomic% and the aluminum content was 0.2 atomic%. Furthermore, the electrophotographic roller Y-13 was evaluated in the same manner as in Example 1.

[0124] (Comparative Example 6) A 4mm outer diameter shaft was press-fitted into a silicone sponge (model number: RBWSS12, manufactured by Misumi Corporation), and both ends were cut off to obtain a roller with a 220mm long rubber layer. The outer surface of the roller was polished at a rotational speed of 1800 rpm and a feed rate of 800 mm / min to an outer diameter of 11 mm to produce the electrophotographic roller X-6 according to Comparative Example 6. Furthermore, the electrophotographic roller X-6 was evaluated in the same manner as in Example 1.

[0125] (Comparative Example 7) Hydrotalcite compounds (Mg 0.75 Al 0.25 (OH)2(CO3) 0.13 Comparative Example 6's electrophotographic roller X-7 was prepared by first scattering 0.5H2O (product name: DHT-4A, manufactured by Kyowa Chemical Industry Co., Ltd.) as uniformly as possible on a flat surface, then rotating the electrophotographic roller X-1 of Comparative Example 1 several times to coat it thoroughly, and finally blowing off excess particles with air. The amount of particles attached was 72 mg. Furthermore, the electrophotographic roller X-7 was evaluated in the same manner as in Example 1.

[0126] (Comparative Example 8) Under an argon atmosphere, 22.9 g of methyl methacrylate, 9.0 g of dimethylaminoethyl methacrylate, and 1.0 g of benzoyl peroxide were dissolved in 85 g of ethanol and reacted at 80°C for 4 hours. Subsequently, the mixture was heated in an open system to evaporate the ethanol and obtain a random copolymer. (F) Two parts of the random copolymer were added instead of the particles, and it was confirmed that it dissolved uniformly in solution B. Subsequently, an electrophotographic roller X-8 according to Comparative Example 8 was prepared in the same manner as in Example 1, except that surface treatment with ultraviolet light was not performed, and it was evaluated in the same manner as in Example 1.

[0127] (Comparative Example 9) (F) Two parts of trimethyloctylammonium bromide were added instead of particles, and it was confirmed that it dissolved uniformly in solution B. Subsequently, an electrophotographic roller X-9 according to Comparative Example 9 was prepared in the same manner as in Example 1, except that surface treatment with ultraviolet light was not performed, and it was evaluated in the same manner as in Example 1.

[0128] (Comparative Example 10) A roller with an outer diameter of 13 mm was obtained by molding the same urethane rubber composition as in Example 12 using a cylindrical member with an inner diameter of 13 mm. The outer surface of the roller was polished at a rotational speed of 1800 rpm and a feed rate of 800 mm / min to an outer diameter of 11 mm, thereby producing the electrophotographic roller X-10 according to Comparative Example 10. Furthermore, the electrophotographic roller X-10 was evaluated in the same manner as in Example 1. [Table 3] In the table, S1 is the total atomic percentage of metal elements with a Pauling electronegativity of 1.70 or less, measured by X-ray photoelectron spectroscopy of the outer surface of the foam layer. S2 is the total atomic percentage of metal elements with a Pauling electronegativity of 1.70 or less, measured by X-ray photoelectron spectroscopy of the inner wall of the cell opened on the outer surface of the electrophotographic roller. ) indicates.

[0129] Examples 1-17 exhibited a zero-point charge of 40 μC / g or higher, resulting in a significant talc recovery effect and a negative and large absolute value for the charge per unit mass Q / M on the toner carrier. Consequently, a good effect in preventing talc paper fogging was obtained. In particular, Examples 1-8, 10, 13-15, and 17 showed a tendency to exhibit better resistance to talc paper fogging because their zero-point charge was 44 μC / g or higher. Note that Example 12 was evaluated as a reference example.

[0130] Furthermore, since Examples 1, 5, 8, 10, and 13 had a zero-point charge of 55 μC / g or higher, they tended to exhibit particularly good talc paper cover performance. Furthermore, Examples 1-4 showed a low zero-point charge due to the effect of lone pairs of electrons derived from the urethane group. As a result, they were able to better prevent talc paper covering compared to Examples 13-16, which used the same amount and type of particles.

[0131] Comparative Examples 1-6 and 8-10 had zero-point charge levels of less than 40 μC / g. This suggests that the charge per unit mass Q / M on the toner carrier was negative and had a small absolute value, resulting in talc paper fogging. Furthermore, Comparative Example 2 used the same type and quantity of particles as Example 1, but without ultraviolet treatment. As a result, the particles were not exposed from the inner wall of the cell, and the zero-point charge was less than 40 μC / g. Consequently, the charge amount Q / M per unit mass on the toner carrier was negative and had a small absolute value, which is thought to have caused talc paper fogging.

[0132] Furthermore, Comparative Example 10 used the same type and amount of random copolymer as Example 12. However, the polishing treatment reduced the proportion of random copolymer on the outer surface of the foam layer, resulting in a zero-point charge of less than 40 μC / g. As a result, the charge per unit mass Q / M on the toner carrier was negative and had a small absolute value, which is thought to have caused talc paper fogging.

[0133] Comparative Example 7 only physically adheres particles to the foam layer, so the particles become detached during durability, making it impossible to recover the talc in the toner carrier. As a result, talc fogging is likely to occur. After evaluation, the X-7 electrophotographic roller was removed from the cartridge, the toner was removed, and the zero-point charge was measured at 34 μC / g. The toner removal process was performed using the following method. First, the electrophotographic roller was air-blown to remove toner from inside the foam structure. Then, the roller was ultrasonically cleaned in water using an ultrasonic cleaner and dried in a 60°C oven for 12 hours.

[0134] (Example 18) The electrostatic roller brush was removed from the cartridge of a laser printer (product name: HP LaserJet Pro M102w Printer, manufactured by Hewlett-Packard). Furthermore, the electrophotographic roller Y-1 was modified to be installed as a cleaning roller that contacts and rotates the photoreceptor. The talc paper cover value and the charge amount Q / M per unit mass on the developer carrier were calculated in the same manner as in Example 1.

[0135] (Example 19, Comparative Example 11) The evaluation was the same as in Example 18, except that the type of electrophotographic roller was changed as shown in Table 4.

[0136] [Table 4]

[0137] In Examples 18 and 19, since the zero-point charge was 40 μC / g or higher, talc on the photoreceptor could be recovered, and the adhesion of talc to the toner carrier was suppressed. As a result, a good effect in preventing talc paper fogging was obtained. In Comparative Example 11, the zero-point charge is less than 40 μC / g, meaning that the talc on the photoreceptor cannot be recovered. As a result, talc adheres to the toner carrier, making talc fogging more likely.

[0138] This disclosure relates to the following configuration. (Composition 1) A roller for electrophotography, It has a substrate and a foam layer on the outer peripheral surface of the substrate. The foam layer has a plurality of cells opening to the outer surface. The foam layer constitutes the outer surface of the electrophotographic roller. An electrophotographic roller, characterized in that the zero-point charge of the foam layer measured using a standard carrier is 40 μC / g or more. (Configuration 2) The foam layer contains particles. At least a part of the particles is exposed from the inner wall of the cell. The particles contain a compound containing at least one metal element. The electrophotographic roller according to Configuration 1, wherein the electronegativity of the polling of the metal element is 1.70 or less. (Configuration 3) The electrophotographic roller according to Configuration 2, wherein the particles contain a hydrotalcite compound represented by the following formula (1): Mg (1-x) Al x (OH)2(CO3) x / 2 ·mH2O ···(1) (In formula (1), x satisfies 0.00 < x ≤ 0.50, and m is a positive number). (Configuration 4) The electrophotographic roller according to Configuration 2, wherein the particles contain magnesium oxide. (Configuration 5) The electrophotographic roller according to any one of Configurations 2 to 4, wherein the total content ratio S1 of the metal element having an electronegativity of polling of 1.70 or less measured by X-ray photoelectron spectroscopy on the outer surface of the foam layer is 0.4 atomic% or more. (Configuration 6) The electrophotographic roller according to any one of Configurations 2 to 5, wherein the total content ratio of the metal element having an electronegativity of polling of 1.70 or less measured by X-ray photoelectron spectroscopy on the inner wall of the cell of the foam layer is 0.4 atomic% or more. (Configuration 7) The electrophotographic roller according to any one of Configurations 1 to 6, wherein the foam layer contains polyurethane as a binder resin. The electrophotographic roller according to the above. (Composition 8) A process cartridge that is detachably configured to be attached to the main body of an electrophotographic image forming apparatus, characterized in that it comprises an electrophotographic roller as described in any of configurations 1 to 7. (Composition 9) The process cartridge according to configuration 8, wherein the process cartridge comprises a photoreceptor and a toner carrier for transporting toner to the surface of the photoreceptor, and the electrophotographic roller is at least one of a toner supply roller for supplying the toner to the surface of the toner carrier and a cleaning roller for cleaning the photoreceptor. (Composition 10) An electrophotographic image forming apparatus characterized by comprising an electrophotographic roller as described in any of configurations 1 to 7. (Composition 11) The aforementioned electrophotographic image forming apparatus, photoreceptor, A toner carrier that transports toner to the surface of the photoreceptor, A toner supply roller that supplies the toner to the surface of the toner carrier and A cleaning roller for cleaning the photoreceptor, Equipped with, The electrophotographic image forming apparatus according to configuration 10, wherein the electrophotographic roller is at least one of the toner supply roller and the cleaning roller. [Explanation of symbols]

[0139] 1. Electrophotographic roller, 2. Foam layer, 3. Substrate, 5 Cleaning blade, 6 Charging roller, 7 Toner carrier, 8 Toner supply roller, 9 Toner, 10 Toner regulating member, 11 Photoconductor, 12 Charging roller brush, 13 Cleaning roller, 21 Lower piece member, 22 Cylindrical member, 23 Upper piece member, 24 Core metal (base), 25 Urethane rubber composition, 31 Funnel, 32 Recovery container, 33 Insulating board, 34 Capacitor, 35 Voltmeter 36 Mixing chamber, 37 Agitation rotor

Claims

1. An electrophotographic roller having a substrate and a foamed layer on the outer surface of the substrate, The foamed layer constitutes the outer surface of the electrophotographic roller, The foamed layer has a plurality of cells that open to the outer surface, The foamed layer contains particles, At least a portion of the particles is exposed from the inner wall of the cell, The particles contain a compound comprising at least one metal element, The Pauling electronegativity of the metal element is 1.70 or less. An electrophotographic roller characterized in that the zero-point charge of the foamed layer, measured using a standard carrier, is 40 μC / g or more.

2. The electrophotographic roller according to claim 1, wherein the particles contain a hydrotalcite compound represented by the following formula (1): Mg （１－ｘ） Al ｘ (OH) ２ (CO ３ ) ｘ／２ mH ２ O ... (1) (In equation (1), x satisfies 0.00 < x ≤ 0.50, and m is a positive number.)

3. The electrophotographic roller according to claim 1, wherein the particles contain magnesium oxide.

4. The electrophotographic roller according to any one of claims 1 to 3, wherein the total content S1 of the metal elements with a Pauling electronegativity of 1.70 or less, as measured by X-ray photoelectron spectroscopy analysis of the outer surface of the foam layer, is 0.4 atomic% or more.

5. An electrophotographic roller according to any one of claims 1 to 3, wherein the total content S2 of the metal elements with a Pauling electronegativity of 1.70 or less, as measured by X-ray photoelectron spectroscopy analysis of the inner wall of the cell in the foam layer, is 0.4 atomic% or more.

6. The electrophotographic roller according to any one of claims 1 to 3, wherein the foamed layer contains polyurethane as a binder resin.

7. A process cartridge that is detachably attached to the main body of an electrophotographic image forming apparatus and comprises an electrophotographic roller as described in any one of claims 1 to 3.

8. The aforementioned process cartridge The aforementioned electrophotographic roller, Photoreceptor and A toner carrier that transports toner to the surface of the photoreceptor. It is equipped with, The process cartridge according to claim 7, wherein the electrophotographic roller is at least one of a toner supply roller that supplies toner to the surface of the toner carrier and a cleaning roller that cleans the photoreceptor.

9. An electrophotographic image forming apparatus characterized by comprising an electrophotographic roller as described in any one of claims 1 to 3.

10. The aforementioned electrophotographic image forming apparatus, photoreceptor, A toner carrier that transports toner to the surface of the photoreceptor, A toner supply roller that supplies the toner to the surface of the toner carrier and A cleaning roller for cleaning the photoreceptor. It is equipped with, The electrophotographic image forming apparatus according to claim 9, wherein the electrophotographic roller is at least one of the toner supply roller and the cleaning roller.

11. The electrophotographic image forming apparatus, The aforementioned electrophotographic roller Photoreceptor and A toner carrier that transports toner to the surface of the photoreceptor. It is equipped with, The electrophotographic roller is at least one of a toner supply roller that supplies toner to the surface of the toner carrier and a cleaning roller that cleans the photoreceptor. The electrophotographic image forming apparatus according to claim 9.

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