Image forming apparatus and image forming method

Abstract

To provide an image forming device and image forming method, which offer both curling resistance and cleaning performance in high-speed image forming.SOLUTION: An image forming device with a mechanism for cleaning an image carrier surface with a cleaning blade is provided, where a surface layer of the image carrier contains at least a binder resin composed of a polymer of a curable monomer, and the cleaning blade has a region with a fluid first lubricant provided on each end thereof in a longitudinal direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an image forming apparatus and an image forming method, and more particularly to an image forming apparatus and an image forming method that can achieve both curling resistance and cleanability in high-speed image formation. [Background technology]

[0002] In recent high-speed image formation, for example, when forming an electrophotographic image, there is a process in which a toner image is formed on an image carrier and the toner image on the image carrier is transferred repeatedly. During this process, some toner remains on the image carrier without being completely transferred, and means for removing this include fur brushes and blades, with cleaning blades nowadays being the main means.

[0003] Typically, the longitudinal length of a cleaning blade is designed to be sufficiently longer than the area where a toner image is formed on the image carrier (inside the image forming area), since it is necessary to also clean scattered toner in areas where no toner image is formed on the image carrier (outside the image forming area).However, since there is less toner and external additives in areas where no toner image is formed on the image carrier (outside the image forming area), there is a problem that the cleaning blade is prone to curling up.

[0004] Therefore, in order to prevent the cleaning blade from turning up, a cleaning blade has been proposed that has a resin film on the surface of at least both ends outside the development area (image forming area) in the longitudinal direction (Patent Document 1). However, there is a problem in that toner and free external additives slip through the boundary between the area with the resin film and the area without the resin film, which raises concerns about cleanability.

[0005] In addition, a cleaning blade has been proposed in which both ends of a cleaning blade are impregnated with an isocyanate compound to cause swelling, and the difference in level between the treated and untreated areas impregnated with the isocyanate compound is controlled to within a range of 5 to 30 μm, thereby suppressing curling of the cleaning blade and simultaneously realizing good cleaning performance (Patent Document 2).

[0006] However, in order to compensate for the deterioration of cleaning performance due to the recent increase in speed of image formation processes and the reduction in toner diameter, it is necessary to design the pressure (contact pressure) with which the cleaning blade is pressed against the image carrier to be high, and there is a problem that the effect of suppressing curling is insufficient just by impregnating the edge.

[0007] Furthermore, slight differences in level or hardness between the treated and untreated areas cause local wear at the edge of the image carrier, which can cause poor cleaning of the edge, with toner etc. slipping through from the local wear. In view of the above, in the recent trend of high-speed image formation, further improvements are required in electrophotographic image forming apparatuses to achieve both resistance to curling and cleanability. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-162885 [Patent Document 2] Japanese Patent Application Laid-Open No. 2010-170157 Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention has been made in consideration of the above problems and circumstances, and the problem to be solved is to provide an image forming apparatus and an image forming method that can achieve both curling resistance and cleanability in high-speed image formation. [Means for solving the problem]

[0010] In order to solve the above-mentioned problems, the present inventors have investigated the causes of the above-mentioned problems and have found that the above-mentioned problems can be solved by an image forming apparatus having a mechanism for cleaning the surface layer of an image carrier containing a binder resin made of at least a polymer of a curable monomer with a cleaning blade having an area in which a lubricant having fluidity is present in a specific range, thereby arriving at the present invention. That is, the above-mentioned problems of the present invention are solved by the following means.

[0011] 1. An image forming apparatus having a mechanism for cleaning the surface of an image carrier with a cleaning blade, wherein the surface layer of the image carrier contains a binder resin made of at least a polymer of a curable monomer, and the cleaning blade has regions at both ends in the longitudinal direction where a first lubricant having fluidity is present. The first lubricant present in the regions at both ends is grease, the first lubricant present in the regions at both ends contains a silicone resin component, and the universal hardness of the surface layer is 200 to 360 N / mm 2 and a region in the longitudinal center where a second lubricant different from the first lubricant present in the regions at both ends is present, the second lubricant being zinc stearate, and the regions at both ends where the first lubricant is present are regions of 4 to 8% of the entire length in the longitudinal direction from the ends of the both ends toward the center. An image forming apparatus comprising:

[0018] 2 The first aspect is characterized in that the surface layer contains a binder resin, and the binder resin contains at least a polymerizable hardened product of an acrylic monomer or a methacrylic monomer. In the section The image forming apparatus described above.

[0019] 3 Item 1, characterized in that the surface layer contains resin particles having a melamine structure. or No. In item 2 The image forming apparatus described above.

[0020] 4 The resin particles are particles containing melamine-formaldehyde resin. 3 Item 1. The image forming apparatus according to item 1.

[0021] 5 The surface layer contains inorganic particles. 4 Item 1. The image forming apparatus according to any one of items 1 to 5.

[0022] 6 The inorganic particles contain metal oxide particles. 5 Item 1. The image forming apparatus according to item 1.

[0023] 7 The metal oxide particles are tin oxide particles. 6 Item 1. The image forming apparatus according to item 1.

[0025] 8 An image forming method using a toner for developing an electrostatic latent image, in which an image carrier is used in the electrostatic latent image forming step or the toner image transferring step, and the image carrier contains a binder resin made of at least a polymer of a curable monomer in the surface layer of the image carrier, and the surface of the image carrier is cleaned with a cleaning blade having an area where a first lubricant having fluidity is present at both ends in the longitudinal direction. The first lubricant present in the regions at both ends is grease, the first lubricant present in the regions at both ends contains a silicone resin component, and the universal hardness of the surface layer is 200 to 360 N / mm 2 and a region in the longitudinal center where a second lubricant different from the first lubricant present in the regions at both ends is present, the second lubricant being zinc stearate, and the regions at both ends where the first lubricant is present are regions of 4 to 8% of the entire length in the longitudinal direction from the ends of the both ends toward the center. An image forming method comprising:

[0026] 9. The cleaning blade is characterized in that it has a region in the center in the longitudinal direction where a second lubricant different from the first lubricant present in the regions at both ends is present. 8 Item 1. The image forming method according to item 1. [Effects of the Invention]

[0027] According to the above-described means of the present invention, it is possible to provide an image forming apparatus that can achieve both resistance to curling and cleanability in high-speed image formation.

[0028] The mechanism by which the effects of the present invention are manifested or the mechanism of action is not clear, but is speculated as follows.

[0029] The present invention is an image forming apparatus having a mechanism for cleaning the surface of an image carrier with a cleaning blade, characterized in that the surface layer of the image carrier contains a binder resin consisting of at least a polymer of a curable monomer, and the cleaning blade has an area at both ends in the longitudinal direction where a first lubricant having fluidity is present.

[0030] As described above, it has been difficult to achieve both curling resistance and cleaning performance in conventional cleaning blades that have at least a resin film on the surface of both ends outside the image forming area in the longitudinal direction, or cleaning blades that have both ends impregnated with an isocyanate compound.

[0031] In the image forming apparatus of the present invention, by combining a cleaning blade having an area where a first lubricant having fluidity is present at both ends in the longitudinal direction with an image carrier using a cured resin with high surface hardness as the binder resin, it is possible to achieve both cleaning performance and resistance to peeling, which was difficult with conventional methods.

[0032] According to the present invention, even if the contact pressure of the cleaning blade against the image carrier is designed to be sufficiently high, the first lubricant, which has fluidity, is transferred from the cleaning blade to the image carrier and spreads uniformly, thereby effectively suppressing curling of the cleaning blade.

[0033] Furthermore, since the image carrier according to the present invention has a high surface hardness, the first lubricant having fluidity remaining on the image carrier is less likely to be scraped off by the cleaning blade and remains on the image carrier for a long period of time, thereby enabling the excellent effect of suppressing the cleaning blade from curling to be maintained for a long period of time.

[0034] Furthermore, the first lubricant, which has fluidity and remains on the image carrier, does not create a step between the areas where the lubricant is present and the areas where it is not present, and in addition, the surface hardness of the image carrier is high, so local wear does not occur at the ends of the image carrier and poor cleaning of the ends does not occur. [Brief explanation of the drawings]

[0035] [Figure 1] 1 is a cross-sectional view showing an example of the configuration of an image carrier of the present invention; [Figure 2] (a) A diagram showing an example of a normal contact state between an image carrier and a cleaning blade (counter type). (b) A diagram showing an example of a normal contact state between an image carrier and a cleaning blade (with type). [Figure 3] 1 is a diagram showing an example of an area where lubricant is applied to a cleaning blade; [Figure 4] Schematic cross-sectional view showing the structure of a tandem-type electrophotographic image forming apparatus equipped with an image carrier. [Figure 5] FIG. 1 is a diagram illustrating an example of a configuration of a main part of an image forming unit. [Figure 6] Schematic diagram for explaining the cleaning blade evaluation method (test image consisting of a vertical band-shaped solid image with 80% coverage) [Figure 7] Schematic diagram for explaining the cleaning blade evaluation method (test image consisting of a vertical band-shaped solid image with 10% coverage) DETAILED DESCRIPTION OF THE INVENTION

[0036] The image forming apparatus of the present invention is an image forming apparatus having a mechanism for cleaning the surface of an image carrier with a cleaning blade, characterized in that the surface layer of the image carrier contains a binder resin consisting of at least a polymer of a curable monomer, and the cleaning blade has an area at both ends in the longitudinal direction where a first lubricant having fluidity is present. This feature is a technical feature common to or corresponding to each of the following embodiments (modes).

[0037] In an embodiment of the present invention, it is preferable that the first lubricant present in the regions at both ends is liquid from the viewpoint of maintaining the migration, spreadability and lubricity of the lubricant.

[0038] It is preferable that the first lubricant present in the regions at both ends is grease, since this does not spread too much and contributes to maintaining lubricity.

[0039] It is preferable that the first lubricant present in the regions at both ends contains a silicone resin component from the viewpoint of the lubricity of the lubricant itself.

[0040] It is preferable to have a region in the center of the longitudinal direction where a second lubricant of a type different from the first lubricant present in the regions at both ends is present, from the viewpoint of reducing wear between the image carrier and the cleaning blade and improving durability.

[0041] It is preferable that the regions at both ends where the first lubricant is present be regions extending from the ends of the both ends toward the center portion to 8% or less of the total longitudinal length, from the viewpoint of maintaining the wetting and spreading of the first lubricant and uniform lubrication.

[0042] It is preferable that the regions at both ends where the first lubricant is present be regions extending from the ends of the both ends toward the center portion to 5% or less of the total longitudinal length, from the viewpoint of maintaining the wetting and spreading of the first lubricant and uniform lubrication.

[0043] From the viewpoint of improving the hardness of the surface layer, it is preferable that the surface layer contains a binder resin, and that the binder resin contains at least a polymerizable cured product of an acrylic monomer or a methacrylic monomer.

[0044] It is preferable that the surface layer contains resin particles having a melamine structure, from the viewpoint of imparting appropriate irregularities to the shape of the surface layer and improving the cleaning properties.

[0045] It is more preferable that the resin particles are particles containing melamine-formaldehyde resin, in order to provide the surface layer with appropriate irregularities and improve the cleaning properties.

[0046] The surface layer preferably contains inorganic particles from the viewpoint of strength and control of electrical conductivity.

[0047] It is more preferable that the inorganic particles contain metal oxide particles from the viewpoint of strength and control of conductivity.

[0048] It is more preferable that the metal oxide particles are tin oxide particles from the viewpoint of strength and control of conductivity.

[0049] The universal hardness of the surface layer is 150 to 350 N / mm 2 It is preferable that the range is within the range from the viewpoint of suppressing image defects and providing good cleaning properties.

[0050] The image forming method of the present invention is an image forming method using a toner for developing an electrostatic latent image, characterized in that an image carrier is used in the electrostatic latent image forming step or the toner image transfer step, and the image carrier contains a binder resin consisting of at least a polymer of a curable monomer in the surface layer of the image carrier, and the surface of the image carrier is cleaned with a cleaning blade having areas in which a first lubricant having fluidity is present at both ends in the longitudinal direction.

[0051] In addition, it is preferable to use the cleaning blade having a region in the center in the longitudinal direction where a second lubricant different from the first lubricant present in the regions at both ends is present, from the viewpoint of reducing wear between the image carrier and the cleaning blade and improving durability.

[0052] The present invention, its components, and embodiments for carrying out the present invention will be described in detail below. In this application, the symbol "to" is used to mean that the numerical values ​​before and after it are included as lower and upper limits.

[0053] 1. Image forming device The image forming apparatus of the present invention is an image forming apparatus having a mechanism for cleaning the surface of an image carrier with a cleaning blade, characterized in that the surface layer of the image carrier contains a binder resin consisting of at least a polymer of a curable monomer, and the cleaning blade has an area at both ends in the longitudinal direction where a first lubricant having fluidity is present.

[0054] (1.1) Image carrier The image bearing member provided in the image forming apparatus of the present invention has a surface layer on a support. In the present invention, the term "image carrier" includes both a "photosensitive member" and an "intermediate transfer belt."

[0055] A specific example of the image carrier according to the present invention is one having a layer structure in which, as shown in FIG. 1, a charge generating layer 1c and a charge transport layer 1d as a photosensitive layer 1α, and a surface layer 1e are laminated in this order on a conductive support 1a, and an intermediate layer 1b is provided between the conductive support 1a and the photosensitive layer 1α, as necessary.

[0056] The surface layer preferably contains inorganic particles from the viewpoint of strength and control of electrical conductivity. Another example of the image carrier according to the present invention is one having a layer structure in which an intermediate layer, a single layer having a charge generating function and a charge transport function as a photosensitive layer, and a surface layer are laminated in this order on a conductive support.

[0057] (1.1.1) Surface layer The surface layer constituting the image bearing member according to the present invention contains at least a binder resin made of a polymer of a curable monomer. Furthermore, the surface layer may contain a polymer of a general monomer that is not a polymer of a curable monomer, but it is preferable from the viewpoint of improving the hardness of the surface layer that the binder resin contained in the surface layer contains at least a polymerized cured product (polymer) of an acrylic monomer or a methacrylic monomer.

[0058] (a) Resin type and other additives contained in the surface layer (a-1) Binder resin composed of a polymer of a curable monomer The binder resin made of a polymer of the curable monomer (polymerizable compound) is a resin formed by polymerizing (curing) a monomer having bifunctional or higher reactive groups in the molecule through a polymerization reaction using heat, UV, electron beams, etc.

[0059] The polymerizable group contained in the curable monomer (polymerizable compound) preferably has a carbon-carbon double bond and is polymerizable.

[0060] The polymerizable group is particularly preferably an acryloyloxy group (CH2=CHCOO-) or a methacryloyloxy group (CH2=C(CH3)COO-), since these groups can be cured with a small amount of light or in a short time.

[0061] The curable monomer (polymerizable compound) can be synthesized by a known method, and is also available as a commercially available product.

[0062] Examples of the binder resin include polystyrene and polyacrylate.

[0063] The curable monomer (polymerizable compound) is preferably a radical curable (polymerizable) monomer that cures via a radical polymerization reaction.

[0064] Specifically, examples of the curable monomer (polymerizable compound) include styrene-based monomers, acrylic-based monomers, methacrylic-based monomers, vinyltoluene-based monomers, vinyl acetate-based monomers, and N-vinylpyrrolidone-based monomers.

[0065] As the curable monomer (polymerizable compound), an acrylic monomer having two or more acryloyl groups (CH2=CHCO-) ​​or methacryloyl groups (CH2=CCH3CO-) or an oligomer thereof is particularly preferred, since it can be cured with a small amount of light or in a short time.

[0066] In the present invention, the curable monomers (polymerizable compounds) may be used alone or in combination. These curable monomers (polymerizable compounds) may be used as monomers or may be used after oligomerization. Specific examples of the curable monomer (polymerizable compound) are shown below.

[0067] [ka]

[0068] [ka]

[0069] In the chemical formulas showing the above exemplary compounds (M1) to (M14), R represents an acryloyl group (CH2=CHCO-), and R' represents a methacryloyl group (CH2=CCH3CO-).

[0070] As the curable monomer (polymerizable compound), it is preferable to use a monomer having three or more polymerizable functional groups. Furthermore, as the curable monomer (polymerizable compound), two or more compounds may be used in combination, but even in this case, it is preferable to use a monomer having three or more polymerizable functional groups in a proportion of 50 mass % or more.

[0071] (radical scavenger) The above curable monomer (polymerizable compound) is preferably polymerized in the presence of a specific radical scavenger represented by the following general formula (1).

[0072] [ka]

[0073] In the general formula (1), R1 and R2 each independently represent an alkyl group having 1 to 6 carbon atoms. By using an alkyl group having 1 to 6 carbon atoms as R1 and R2, the influence of steric hindrance of the radical scavenger can be reduced, and the crosslinking reaction can be suitably controlled. Furthermore, from the viewpoint of the stability of the trapped radicals, R1 and R2 are preferably a tert-butyl group or a tert-pentyl group.

[0074] This particular radical scavenger acts as a capping agent for crosslinking. That is, the crosslink density (film strength of the cured film) of a specific radical scavenger can be adjusted by adjusting the addition ratio thereof, etc.

[0075] Therefore, since the binder resin component consisting of a polymer of a curable monomer is obtained by polymerizing a polymerizable compound in the presence of a specific radical scavenger, the protective layer has appropriate film strength (abrasion resistance), and the photosensitive body surface is appropriately worn down by a cleaning means such as a blade.

[0076] Therefore, even if discharge products or the like adhere to the surface of the photosensitive member, the surface of the photosensitive member is worn down and refreshed, so that image deletion can be prevented.

[0077] The radical polymerization initiator is not particularly limited, but a photopolymerization initiator is preferred, and among these, an acylphosphine oxide compound and an oxime ester compound are preferred. Specific examples of acylphosphine oxide compounds and oxime ester compounds are shown below.

[0078] [ka]

[0079] These polymerization initiators may be used alone or in combination of two or more. The content of the polymerization initiator is within a range of 0.1 to 20 parts by mass, and preferably within a range of 0.5 to 10 parts by mass, per 100 parts by mass of the polymerizable compound.

[0080] (a-2) Inorganic particles The surface layer preferably contains inorganic particles from the viewpoint of strength and control of electrical conductivity.

[0081] (metal oxide particles) As the inorganic particles, general particles such as inorganic oxide particles and metal oxide particles can be used, but it is more preferable that the inorganic particles contain metal oxide particles from the viewpoint of strength and control of conductivity.

[0082] Metal oxide particles have high strength and moderate conductivity, and therefore it is easy to control the strength and conductivity required for the image bearing member in the image forming process.

[0083] Examples of metal oxide particles that can be used to form the protective layer include silica (silicon oxide), magnesium oxide, zinc oxide, lead oxide, alumina (aluminum oxide), zirconium oxide, tin oxide, titania (titanium oxide), niobium oxide, molybdenum oxide, and vanadium oxide. From the viewpoint of strength and control of conductivity, it is more preferable that the metal oxide particles are tin oxide particles.

[0084] (Number average primary particle size of metal oxide particles) The number average particle size of the metal oxide particles is preferably within a range of 10 to 500 nm, more preferably within a range of 3 to 100 nm, and even more preferably within a range of 5 to 40 nm.

[0085] The number average primary particle diameter of metal oxide particles can be calculated, for example, by taking a 10,000x magnified photograph using a scanning electron microscope (manufactured by JEOL Ltd.), randomly capturing 300 particles using a scanner, and then using the photographic image (aggregated particles excluded) of the particles to process the image using an automatic image processing analyzer "LUZEX AP (software version Ver. 1.32)" (manufactured by Nireco Corporation).

[0086] The measurement of the number average primary particle size of the metal oxide particles is carried out on metal oxide particles that do not contain chemical species (coating layer) derived from a surface modifier.

[0087] Even if metal oxide particles are subjected to a surface modification treatment, it is believed that the thickness will be within the tolerance range of the metal oxide particles (roughly 1 / 10,000 of the metal oxide particle diameter). For this reason, it is believed that the surface modification treatment will not change the average primary particle diameter.

[0088] Furthermore, the cleaning performance improving effect of the organic resin particles, which will be described later, is exhibited when the organic resin particles come into contact with the toner, so it is preferable that the number average primary particle diameter of the inorganic particles is smaller than that of the organic resin particles.

[0089] When inorganic particles aggregate, it is preferable that the secondary particle diameter is smaller than that of organic resin particles. In this case, when inorganic particles aggregate, it is generally considered that 2 to 3 primary particles aggregate, so the secondary particle diameter may be considered to be at most about 2.5 times the number average primary particle diameter.

[0090] For example, in the case of inorganic particles with a number average primary particle size of 20 nm, the secondary particle size may be considered to be a maximum of about 50 nm.

[0091] (Surface modifier for metal oxide particles) The metal oxide particles may be surface-modified with a surface modifier having a reactive organic group (hereinafter also referred to as a "reactive organic group-containing surface modifier").

[0092] The surface modification treatment can be carried out by subjecting untreated metal oxide particles, which are raw materials, to a surface modification treatment using a surface modifier.

[0093] Metal oxide particles that have been surface-modified with a surface modifier are considered to become surface-coated fillers that contain chemical species (coating layer) derived from the surface modifier and metal oxide particles. The surface-modified metal oxide particles only need to have a chemical species (coating layer) derived from the surface modifier on at least a portion of their surface.

[0094] When the surface of metal oxide particles is modified with a surface modifier, the metal oxide particles are efficiently rendered hydrophobic.

[0095] When the outermost layer of a photoreceptor is formed using metal oxide particles that have been surface-modified in this manner and a binder resin made of a polymer of a curable monomer, the compatibility of the surface-modified metal oxide particles with the polymer of the curable monomer is improved, which is advantageous for uniform dispersion in the outermost layer.

[0096] The reactive organic group-containing surface modifier is preferably one that reacts with hydroxy groups present on the surface of metal oxide particles, and examples of such reactive organic group-containing surface modifiers include silane coupling agents and titanium coupling agents.

[0097] Furthermore, as the reactive organic group-containing surface modifying agent, a surface modifying agent having a radically polymerizable reactive group is preferred. Examples of the radically polymerizable reactive group include a vinyl group, an acryloyl group, and a methacryloyl group. Such a radically polymerizable reactive group can also react with the polymerizable compound according to the present invention to form a strong protective layer.

[0098] As the surface modifying agent having a radically polymerizable reactive group, a silane coupling agent having a radically polymerizable reactive group such as a vinyl group, an acryloyl group, or a methacryloyl group is preferred.

[0099] The reactive organic group-containing surface modifier is preferably a silane coupling agent having the above radical polymerizable group, and examples thereof include the following compounds (S-1) to (S-31).

[0100] S-1: CH2=CHSi(CH3)(OCH3)2 S-2: CH2=CHSi(OCH3)3 S-3:CH2=CHSiCl3 S-4:CH2=CHCOO(CH2)2Si(CH3)(OCH3)2 S-5:CH2=CHCOO(CH2)2Si(OCH3)3 S-6:CH2=CHCOO(CH2)2Si(OC2H5)(OCH3)2 S-7:CH2=CHCOO(CH2)3Si(OCH3)3 S-8:CH2=CHCOO(CH2)2Si(CH3)Cl2 S-9:CH2=CHCOO(CH2)2SiCl3 S-10:CH2=CHCOO(CH2)3Si(CH3)Cl2 S-11:CH2=CHCOO(CH2)3SiCl3 S-12:CH2=C(CH3)COO(CH2)2Si(CH3)(OCH3)2 S-13:CH2=C(CH3)COO(CH2)2Si(OCH3)3 S-14:CH2=C(CH3)COO(CH2)3Si(CH3)(OCH3)2 S-15:CH2=C(CH3)COO(CH2)3Si(OCH3)3 S-16:CH2=C(CH3)COO(CH2)2Si(CH3)Cl2 S-17:CH2=C(CH3)COO(CH2)2SiCl3 S-18:CH2=C(CH3)COO(CH2)3Si(CH3)Cl2 S-19:CH2=C(CH3)COO(CH2)3SiCl3 S-20:CH2=CHSi(C2H5)(OCH3)2 S-21:CH2=C(CH3)Si(OCH3)3 S-22:CH2=C(CH3)Si(OC2H5)3 S-23:CH2=CHSi(OCH3)3 S-24:CH2=C(CH3)Si(CH3)(OCH3)2 S-25:CH2=CHSi(CH3)Cl2 S-26:CH2=CHCOOSi(OCH3)3 S-27: CH2=CHCOOSi(OC2H5)3 S-28: CH2=C(CH3)COOSi(OCH3)3 S-29: CH2=C(CH3)COOSi(OC2H5)3 S-30:CH2=C(CH3)COO(CH2)3Si(OC2H5)3 S-31:CH2=CHCOO(CH2)2Si(CH3)2(OCH3)

[0101] Furthermore, as the surface modifier, in addition to the above exemplary compounds (S-1) to (S-31), a silane compound having a radically polymerizable reactive organic group may also be used. The surface modifiers may be used alone or in combination of two or more.

[0102] The amount of the surface modifier to be used for treatment is preferably within a range of 0.1 to 200 parts by mass, more preferably within a range of 7 to 70 parts by mass, per 100 parts by mass of the fine particles.

[0103] An example of a method for treating untreated metal oxide particles with a reactive organic group-containing surface modifier is a method in which a slurry (a suspension of solid particles) containing untreated metal oxide particles and the reactive organic group-containing surface modifier is wet-pulverized.

[0104] This method prevents the untreated metal oxide particles from re-aggregating, while simultaneously promoting surface modification of the untreated metal oxide particles. The solvent is then removed and the mixture is powdered.

[0105] The surface modification device may be, for example, a wet media dispersion type device. This wet media dispersion device is a device that has a process in which beads are filled as media in a container and an agitator disk attached perpendicular to the rotation axis is rotated at high speed to crush, pulverize, and disperse agglomerates of untreated metal oxide particles.

[0106] The structure of the dispersion is not limited as long as it is a form that allows the untreated metal oxide particles to be sufficiently dispersed and surface-modified when the untreated metal oxide particles are surface-modified.

[0107] For example, various types can be adopted, such as vertical or horizontal, continuous or batch type. Specifically, a sand mill, an ultravisco mill, a pearl mill, a grain mill, a dyno mill, an agitator mill, a dynamic mill, etc. can be used. These dispersion devices use grinding media such as balls and beads to perform fine grinding and dispersion by impact crushing, friction, shear stress, shear stress, etc.

[0108] As beads used in a wet media dispersion type device, balls made from raw materials such as glass, alumina, zircon, zirconia, steel, and flint can be used, with those made from zirconia or zircon being particularly preferred.

[0109] Furthermore, beads having a diameter of about 1 to 2 mm are usually used, but in the present invention, it is preferable to use beads having a diameter of about 0.1 to 1.0 mm.

[0110] The disks and inner walls of the container used in the wet media dispersion device can be made of various materials such as stainless steel, nylon, and ceramic, but in the present invention, ceramic disks and inner walls of the container, such as zirconia or silicon carbide, are particularly preferred.

[0111] (Shape of metal oxide particles) The shape of the metal oxide particles is not particularly limited, and examples thereof include spherical, elliptical in cross section, needle-like, disc-like, and irregular shapes. From the viewpoint of dispersibility, etc., a spherical shape or an elliptical cross section shape is preferred.

[0112] (Metal oxide particle content) The content of the metal oxide particles in the surface layer is preferably within a range of 10 to 200 parts by mass with respect to 100 parts by mass of the binder resin made of a polymer of a curable monomer.

[0113] (a-3) Organic resin particles The surface layer according to the present invention preferably contains organic resin particles. Examples of the organic resin particles include amino resin particles (e.g., melamine resin particles and benzoguanamine resin particles, and melamine particles containing and cured from a monomer selected from acetoguanamine, guanamine, and CTU guanamine), fluororesin particles, silicone resin particles, acrylic resin particles, olefin-based resin particles (e.g., polystyrene resin particles), phenolic resins, and other mixed resin particles. However, it is preferable for the surface layer to contain resin particles having a melamine structure, as this gives the surface layer a suitable unevenness and improves cleaning properties.

[0114] It is more preferable that the resin particles are particles containing melamine-formaldehyde resin, in order to provide the surface layer with appropriate irregularities and improve the cleaning properties.

[0115] The melamine resin particles are particles of a resin containing at least a structural unit derived from melamine, and specific examples thereof include a polycondensation product of melamine and formaldehyde, and a copolycondensation product of melamine, benzoguanamine, and formaldehyde.

[0116] Examples of fluororesin particles include polytetrafluoroethylene (PTFE), polytrifluoroethylene, polyvinylidene fluoride, polyvinyl fluoride, polyfluoroalkyl vinyl ether, polychlorotrifluoroethylene, polyhexafluoropropylene, polydifluorodichloroethylene, and copolymers thereof.

[0117] Examples of silicone resin particles include organopolysiloxanes such as methylhydrogenpolysiloxane, dimethylpolysiloxane, methoxypolysiloxane, methylphenylpolysiloxane, and cyclohexylpolysiloxane.

[0118] Examples of acrylic resin particles include polymers of acrylic acid esters or methacrylic acid esters, and copolymers of acrylic acid esters or methacrylic acid esters with styrene, which may have a crosslinked structure.

[0119] The polystyrene resin particles include styrene polymers, which may have a crosslinked structure.

[0120] The benzoguanamine resin particles include a polycondensate of benzoguanamine and formaldehyde.

[0121] Examples of the olefin resin include polyethylene, polypropylene, polybutene, and polyhexene.

[0122] Specific examples of commercially available organic resin particles include the following compounds:

[0123] Melamine resin particles: Eposter S, Eposter S6, Eposter S12, Eposter M30 (all manufactured by Nippon Shokubai Co., Ltd.), Optobeads 2000M, Optobeads 3500M (all manufactured by Nissan Chemical Co., Ltd.), etc.

[0124] Fluororesin particles: KTL-1N (Kitamura Co., Ltd.), Polymist F5A (Solvay Specialty Polymers Japan Co., Ltd.), etc.

[0125] Silicone resin particles: Tospearl XC99-A8808, Tospearl 120 (both manufactured by Momentive Performance Materials Japan, LLC), KMP-605 (manufactured by Shin-Etsu Chemical Co., Ltd.), etc.

[0126] Acrylic resin particles: Eposter MA1002, Eposter MA1004, Eposter MA2003 (all manufactured by Nippon Shokubai Co., Ltd.), FS102, FS201 (all manufactured by Nippon Paint Industrial Coatings Co., Ltd.), etc.

[0127] Polystyrene resin particles: SX-130H, KSR-3A (both manufactured by Soken Chemical & Engineering Co., Ltd.), etc.

[0128] Benzoguanamine resin particles: Eposter MS (manufactured by Nippon Shokubai Co., Ltd.), etc. Examples include:

[0129] (melamine resin particles) The organic resin particles used in the present invention are preferably melamine resin particles. When melamine resin particles are used, the compatibility with the resin makes it possible to prevent the particles from falling off during long-term use, and therefore it is possible to maintain good cleaning performance for a long period of time.

[0130] (Number average primary particle size of organic resin particles) The number average primary particle diameter of the organic resin particles used in the present invention is within the range of 0.08 to 3.00 μm. The number average primary particle diameter of the organic resin particles is preferably within a range of 0.20 to 2.50 μm, and more preferably within a range of 0.30 to 1.50 μm.

[0131] If the number average primary particle size of the organic resin particles is 0.20 μm or more, good cleaning properties can be obtained, and if it is 0.30 μm or more, even better cleaning properties can be obtained.

[0132] On the other hand, if the number average primary particle diameter of the organic resin particles is 2.50 μm or less, curing inhibition during the formation of the outermost layer is further suppressed, and if it is 1.50 μm or less, curing inhibition is further suppressed, thereby achieving good scratch resistance. The number average primary particle size of the organic resin particles is defined as the number average primary particle size measured by the following method.

[0133] First, an enlarged photograph of a sample (organic resin particles, etc.) taken at a magnification of 30,000 times using a scanning electron microscope (manufactured by JEOL Ltd.) is imported into a scanner.

[0134] Next, from the obtained photographic image, 300 organic resin particle images excluding the aggregated organic resin particles are randomly selected and binarized using an automatic image processing and analysis system, Luzex AP Software Ver. 1.32 (manufactured by Nireco Corporation), and the horizontal Feret diameter of each of the organic resin particle images is calculated.

[0135] Then, the average value of the Feret's diameter in the horizontal direction of each of the organic resin particle images is calculated to be the number average primary particle diameter.

[0136] Here, the horizontal Feret diameter refers to the length of the side parallel to the x-axis of the circumscribing rectangle when the organic resin particle image is binarized.

[0137] (Surface modifier for organic resin particles) The organic resin particles of the present invention may be surface-modified with a surface modifier. The surface modification treatment can be carried out by subjecting untreated organic resin particles, which are raw materials, to a surface modification treatment using a surface modifier.

[0138] The organic resin particles that have been surface-modified with a surface modifier are considered to be surface-coated resin particles that contain organic resin particles and chemical species (coating layer) derived from the surface modifier. The surface-modified organic resin particles only need to have a chemical species (coating layer) derived from the surface modifier on at least a portion of their surface.

[0139] In the present invention, the surface modifying agent used in the surface modification treatment of the organic resin particles is not particularly limited, and any conventionally known surface modifying agent can be used. Specific examples of the surface modifier include silane coupling agents, titanium coupling agents, fluorine-based surface modifiers, and surface modifiers having a silicone chain.

[0140] The surface modifiers may be used alone or in combination of two or more kinds. The surface modifier may be a synthetic product or a commercially available product.

[0141] (Shape of organic resin particles) The shape of the organic resin particles is not particularly limited, and examples thereof include spherical, elliptical in cross section, needle-like, disc-like, irregular, etc. From the viewpoint of improving cleaning properties, spherical is preferred.

[0142] (Organic resin particle content) The organic resin particles are preferably contained in an amount of 3 to 50 parts by mass, more preferably 3 to 30 parts by mass, relative to 100 parts by mass of the cured resin. When the content of the organic resin particles is within the above range, good cleaning properties can be ensured.

[0143] (Method for determining organic resin particle portion and other resin portion) Whether the measured area is an organic resin particle area or other resin area can be determined by observing the surface of the indented area using an AFM (atomic force microscope) or SEM (scanning electron microscope) after the indentation test when measuring the outermost layer hardness, which will be described later. If it is difficult to determine whether the portion being measured is an organic resin particle portion or other resin portion, a coating layer excluding the organic resin particles may be prepared when measuring the hardness of the outermost layer, and the hardness of that layer may be measured.

[0144] (a-4) Other additives The protective layer may further contain other components, such as antioxidants and lubricant particles.

[0145] (antioxidant) As the antioxidant, for example, those described in JP-A No. 2000-305291 can be used.

[0146] (lubricant particles) As the lubricant particles, fluorine atom-containing resin particles can be added. As the fluorine atom-containing resin particles, it is preferable to appropriately select one or more from tetrafluoroethylene resin, trifluorochloroethylene resin, hexafluorochloroethylene propylene resin, vinyl fluoride resin, vinylidene fluoride resin, difluorodichloroethylene resin, and copolymers thereof, with tetrafluoroethylene resin and vinylidene fluoride resin being particularly preferred.

[0147] (b) Universal hardness of the surface layer The universal hardness of the surface layer is 150 to 350 N / mm 2 It is preferable that the range is within the range from the viewpoint of suppressing image defects and providing good cleaning properties.

[0148] If the hardness is lower than this range, the strength of the image bearing member will be low, making the image bearing member more susceptible to scratches caused by abrasion by a cleaning blade or by toner or external additives slipping through, resulting in image defects.

[0149] On the other hand, if the hardness is too high, the cleaning blade in contact with the image carrier becomes more susceptible to wear, and cleaning performance deteriorates rapidly after long-term printing.

[0150] The hardness (universal hardness) of the outermost layer according to the present invention can be controlled by the amounts of the binder resin made of the polymer of the curable monomer, inorganic particles, organic resin particles, and other additives.

[0151] (Universal hardness measurement method) The universal hardness of the surface layer according to the present invention can be measured by an indentation test, nanoindentation, or the like. For example, when a load F is applied to a diamond pyramidal Vickers indenter under a test load using the "Fisherscope HM2000" to indent the surface layer, the universal hardness (HU [N / mm 2 ]) can be obtained.

[0152] The measurement conditions are as follows: Vickers indenter (square pyramidal indenter, angle 136°), indentation speed 0.4 mN / sec, indentation load 2 mN, holding time 5 seconds, measurement environment 20°C, 50% RH. Formula (A): HU (universal hardness) = F / (26.45 × h 2 )

[0153] (c) Thickness of the surface layer The thickness of the surface layer is preferably 10 μm or less.

[0154] (1.1.2) Conductive support The conductive support constituting the image carrier of the present invention may be any material as long as it is conductive, and specific examples include metals such as aluminum, copper, chromium, nickel, zinc, and stainless steel formed into a drum or sheet shape, metal foils such as aluminum and copper laminated onto plastic films, plastic films onto which aluminum, indium oxide, tin oxide, etc. are vapor-deposited, and metals, plastic films, and papers to which a conductive layer is provided by applying a conductive substance alone or together with a binder resin.

[0155] (1.1.3) Middle class In the image bearing member according to the present invention, it is preferable to provide an intermediate layer having a barrier function and an adhesive function between the conductive support and the photosensitive layer from the viewpoint of preventing breakdowns. This intermediate layer contains, for example, a binder resin (hereinafter also referred to as "binder resin for intermediate layer") and, if necessary, metal oxide particles.

[0156] Examples of binder resins for the intermediate layer include casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, polyamide resin, polyurethane resin, gelatin, etc. Among these, alcohol-soluble polyamide resins are preferred.

[0157] Metal oxide particles are used for the purpose of adjusting resistance, and specifically, particles made of various metal oxides such as alumina, zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, and bismuth oxide can be used. Also usable are particles made of tin-doped indium oxide, antimony-doped tin oxide, zirconium oxide, and the like.

[0158] The metal oxide particles may be used alone or in combination of two or more kinds. When two or more kinds are mixed, they may be in the form of a solid solution or fused together.

[0159] The number average particle size of the metal oxide particles is preferably 0.3 μm or less, and more preferably 0.1 μm or less.

[0160] The content of the metal oxide particles in the intermediate layer is preferably within a range of 20 to 400 parts by mass, more preferably within a range of 50 to 350 parts by mass, per 100 parts by mass of the binder resin for the intermediate layer.

[0161] The thickness of the intermediate layer is preferably within the range of 0.1 to 15 μm, and more preferably within the range of 0.3 to 10 μm.

[0162] (1.1.4) Photosensitive layer The photosensitive layer constituting the image bearing member according to the present invention will be described in detail with reference to one having a charge generating layer and a charge transporting layer.

[0163] (1.1.5) Charge generation layer The charge generating layer in the photosensitive layer constituting the image bearing member according to the present invention contains a charge generating substance and a binder resin (hereinafter also referred to as "binder resin for charge generating layer").

[0164] Known resins can be used as the binder resin for the charge generating layer, and specific examples include polystyrene resin, polyethylene resin, polypropylene resin, acrylic resin, methacrylic resin, vinyl chloride resin, vinyl acetate resin, polyvinyl butyral resin, epoxy resin, polyurethane resin, phenolic resin, polyester resin, alkyd resin, polycarbonate resin, silicone resin, melamine resin, as well as copolymer resins containing two or more of these resins (e.g., vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-maleic anhydride copolymer resin), polyvinylcarbazole resin, and the like. Among these resins, polyvinyl butyral resin is preferred.

[0165] The charge generating substance is not particularly limited, and specific examples thereof include azo pigments such as Sudan Red and Diane Blue, quinone pigments such as pyrenequinone and anthanthrone, quinocyanine pigments, perylene pigments, indigo pigments such as indigo and thioindigo, polycyclic quinone pigments such as pyranthrone and diphthaloylpyrene, and phthalocyanine pigments. Among these compounds, polycyclic quinone pigments and titanyl phthalocyanine pigments are preferred. These compounds may be used singly or in combination of two or more.

[0166] The content of the charge generating material in the charge generating layer is preferably within a range of 1 to 600 parts by mass, more preferably within a range of 50 to 500 parts by mass, per 100 parts by mass of the binder resin for the charge generating layer.

[0167] The thickness of the charge generating layer is determined appropriately depending on the characteristics of the binder resin for the charge generating layer, the characteristics and content of the charge generating substance, etc., but is preferably in the range of 0.01 to 5 μm, and more preferably in the range of 0.05 to 3 μm.

[0168] (1.1.6) Charge transport layer The charge transport layer in the photosensitive layer constituting the image bearing member according to the present invention contains a charge transport material and a binder resin (hereinafter also referred to as "binder resin for charge transport layer").

[0169] As the binder resin for the charge transport layer, known resins can be used, and specific examples include polycarbonate resin, polyacrylate resin, polyester resin, polystyrene resin, styrene-acrylonitrile copolymer resin, polymethacrylate resin, and styrene-methacrylate copolymer resin, with polycarbonate resin being preferred. Furthermore, as the polycarbonate resin, BPA (bisphenol A) type, BPZ (bisphenol Z) type, dimethyl BPA type, and BPA-dimethyl BPA copolymer type are preferred from the viewpoints of crack resistance, abrasion resistance, and electrostatic properties.

[0170] Examples of the charge transport material include substances that transport charges (holes), such as triphenylamine derivatives, hydrazone compounds, styryl compounds, benzidine compounds, and butadiene compounds.

[0171] Examples of substances that transport charges (electrons) include metal complexes of fluorene derivatives, carbazole derivatives, azacarbazole derivatives, oxadiazole derivatives, triazole derivatives, silole derivatives, pyridine derivatives, pyrimidine derivatives, and 8-quinolinol derivatives.

[0172] In addition, metal-free or metal phthalocyanine, or those in which the terminals are substituted with alkyl groups, sulfonic acid groups, or the like, can also be preferably used as the substance that transports charges (electrons).

[0173] The content of the charge transport material in the charge transport layer is preferably within a range of 10 to 500 parts by weight, more preferably within a range of 20 to 250 parts by weight, per 100 parts by weight of the binder resin for the charge transport layer.

[0174] The thickness of the charge transport layer varies depending on the properties of the binder resin for the charge transport layer and the properties and content of the charge transport material, but is preferably in the range of 5 to 40 μm, more preferably in the range of 10 to 30 μm.

[0175] The charge transport layer may also contain an antioxidant, an electron conductive agent, a stabilizer, silicone oil, and the like. As the antioxidant, those disclosed in JP-A No. 2000-305291 and the like are preferred, and as the electron conductive agent, those disclosed in JP-A Nos. 50-137543 and 58-76483 and the like are preferred.

[0176] (1.2) Cleaning blade The cleaning blade of the present invention is provided in the image forming apparatus of the present invention, and can be produced by applying a fluid first lubricant to a cleaning blade molded by, for example, a known polyurethane molding method described below. The effects of the present invention are realized by providing the image forming apparatus of the present invention together with the image carrier of the present invention.

[0177] The cleaning blade of the present invention has regions at both longitudinal ends where a first lubricant having fluidity is present, and when the cleaning blade is used to remove toner that has not been completely transferred and remains on the image carrier, the first lubricant present at both longitudinal ends wets and spreads from the contact point, providing uniform lubrication, and since there is no extreme difference in the boundary between the areas where the first lubricant is present and the areas where it is not present, cleaning performance can be maintained for a long period of time.

[0178] In the present invention, the term "image carrier" includes both a "photosensitive member" and an "intermediate transfer belt."

[0179] Furthermore, the first lubricant is transferred from the cleaning blade to the image bearing member, thereby synergistically reducing the torque between the image bearing member and the cleaning blade.

[0180] Furthermore, because the first lubricant is present at both longitudinal ends of the cleaning blade, it can fill in areas where there is little toner or external additives in areas where a toner image is not normally formed on the image carrier (outside the image forming area), thereby maintaining the cleaning blade's resistance to curling without causing toner slip-through or image defects.

[0181] (1.2.1) Definitions of terms (Definition of both ends and center) In the present invention, "both longitudinal ends of the cleaning blade" refers to the area within a range of 10% of the total length in the longitudinal direction from both longitudinal ends of the cleaning blade toward the center.

[0182] In the present invention, the "central portion of the cleaning blade in the longitudinal direction" refers to a region that is outside the range of 10% and less than 80% of the total length in the longitudinal direction from both ends of the cleaning blade toward the central portion.

[0183] (Cleaning blade curling) 2(a) and 2(b) are diagrams showing an example of a contact state between an image carrier and a cleaning blade, for explaining "curling of the cleaning blade." FIG. 2(a) is a diagram showing the normal contact state between an image carrier and a cleaning blade in the counter system, and FIG. 2(b) is a diagram showing the normal contact state between an image carrier and a cleaning blade in the with system. The "normal contact state" between the image carrier and the cleaning blade refers to a contact state between the image carrier and the cleaning blade in a state where the "cleaning blade is not turned up."

[0184] Normally, when the cleaning blade (CL) removes toner remaining on the image carrier, one or more of edge 1, surface A (SA), and surface B (SB) of the cleaning blade are in contact with the image carrier, as shown in Figures 2(a) and 2(b).

[0185] "Cleaning blade curling" refers to the cleaning blade turning over, where one or more of edge 1 (E1), surface A (SA), and surface B (SB) of the cleaning blade are pulled in the driving direction of the image carrier (Y), causing either edge 2 (E2) or surface C (SC), or both, to come into contact with the image carrier.

[0186] Normally, when the cleaning blade (CL) is used to remove toner remaining on the image carrier, as shown in Figure 2(a), the cleaning blade is in contact with the image carrier so that a force is applied in the counter direction to the rotation direction of the image carrier. As a result, the frictional force between the image carrier (Y) and the cleaning blade (CL) becomes excessive, and edge 1 (E1) of the cleaning blade (CL) may be reversed in the rotation direction of the image carrier (Y), causing the cleaning blade to turn over.

[0187] Furthermore, since the cleaning blade (CL) is also required to clean scattered toner in areas on the image carrier (Y) where no toner image is formed (outside the image forming area), the longitudinal length of the cleaning blade (CL) is designed to be sufficiently longer than the areas on the image carrier (Y) where a toner image is formed (inside the image forming area). However, since there is less toner and external additives in the areas on the image carrier (Y) where no toner image is formed (outside the image forming area), and furthermore, since the support member is only on one side, curling often occurs starting from one end or both ends of the cleaning blade (CL).

[0188] (1.2.2) Application area of ​​the first lubricant and the second lubricant having fluidity FIG. 3 is a diagram showing an example of an area where a lubricant is applied to a cleaning blade. The first lubricant having flowability according to the present invention is applied to the end region EP of the cleaning blade (CL) by the method described above. In the present invention, the term "end region" is used synonymously with the aforementioned "both longitudinal end portions of the cleaning blade." In FIG. 3, the first lubricant is present in the end regions EP, which correspond to the "longitudinal ends of the cleaning blade." This spreads from the contact point, providing uniform lubrication, and also eliminating the extreme boundary difference between the areas where the first lubricant is present and the areas where it is not present, thereby enabling the cleaning performance to be maintained for a long period of time.

[0189] Furthermore, the first lubricant is transferred from the cleaning blade to the image carrier Y, thereby synergistically reducing the torque between the image carrier Y and the cleaning blade (CL).

[0190] Furthermore, since the first lubricant is present at both longitudinal ends of the cleaning blade (CL), it can fill in areas where there is little toner or external additives in areas where a toner image is not normally formed on the image carrier Y (outside the image forming area), thereby maintaining the cleaning blade's resistance to curling without causing toner slip-through or image defects.

[0191] The second lubricant according to the present invention, which is different in type from the first lubricant, is supplied to the central region CP of the cleaning blade (CL) by the method described above, and is applied by the brush roller 121, for example. In Figure 3, the second lubricant is applied to the central region CP, which corresponds to the "central portion of the cleaning blade in the longitudinal direction," but the second lubricant may also be applied to the end regions EP or may spread therethrough, thereby reducing wear between the image carrier Y and the cleaning blade and improving durability.

[0192] (1.2.3) First lubricant having flowability In the present invention, the "first lubricant having fluidity" refers to a lubricant that is not fixed to a specific site and that can move and spread from the site where the lubricant was initially present when an external force is applied. A fluid lubricant has the property that when another member comes into contact with a member to which the lubricant is to be applied, the lubricant can be transferred to the member with which the lubricant comes into contact. Due to the above properties, no step occurs between the treated and untreated areas, and cleaning defects due to the step do not occur.

[0193] In the present invention, "fluidity" refers to the property of liquid or powder moving like a flow at a pressure close to the contact pressure of the cleaning blade.

[0194] The form of the first lubricant having flowability according to the present invention may be, for example, a liquid (including semi-solid forms in the present invention) or a powder.

[0195] (liquid lubricant) In an embodiment of the present invention, it is preferable that the first lubricant present in the regions at both ends is liquid from the viewpoint of maintaining the migration, spreadability and lubricity of the lubricant.

[0196] Liquid lubricants include grease and oil. Grease is preferred from the viewpoint that a relatively high viscosity can appropriately suppress the spreading of the liquid lubricant and contribute to maintaining lubricity. Furthermore, it is preferable that the first lubricant present in the regions at both ends contains a silicone resin component from the viewpoint of the lubricity of the lubricant itself.

[0197] 〔grease〕 It is preferable that the first lubricant present in the regions at both ends is grease, as this can appropriately suppress spreading and contribute to maintaining lubricity. In the present invention, "grease" refers to a lubricant in which fine solids called thickeners are dispersed in a liquid lubricant (base oil) to form a semi-solid lubricant that is uniformly mixed.

[0198] Examples of the grease include known greases such as fluorine-based grease, silicone grease, and fluorosilicone grease. Specific examples include Sumitec F936 (manufactured by Sumiko Lubricant Co., Ltd.), G501 (manufactured by Shin-Etsu Chemical Co., Ltd.), and FG-721-1 (manufactured by Shin-Etsu Chemical Co., Ltd.).

[0199] 〔oil〕 Examples of oils include mineral oils, synthetic oils, fluorine-based oils, and silicone oils. Specifically, these include PFPE oil (perfluoropolyether), CTFE oil (a low polymer of chlorotrifluoroethylene), PTFE oil (polytetrafluoroethylene), dimethyl silicone oil, methylphenyl silicone oil, methylhydrogen silicone, reactive silicone oil, and non-reactive silicone oil, examples of which include "Demnum" (manufactured by Daikin Industries, Ltd.) and "KF-96" (manufactured by Shin-Etsu Chemical Co., Ltd.).

[0200] (powder lubricant) Examples of powder lubricants include fine silicone particles and metal salts of fatty acids. Specifically, Tospearl (manufactured by Momentive Performance Materials Japan LLC) can be mentioned.

[0201] (1.2.4) Region where the first lubricant having fluidity is present and its measurement method From the viewpoint of fully obtaining the effect of the first lubricant, it is preferable that the regions at both longitudinal ends of the cleaning blade where the first lubricant having fluidity according to the present invention is present be regions extending from the ends of the both ends toward the center portion to 8% or less of the total longitudinal length, and more preferably 5% or less.

[0202] If the area where the lubricant is present is too narrow, the effect of the lubricant cannot be obtained sufficiently, and curling of the cleaning blade cannot be suppressed. On the other hand, if the area where the lubricant is present is too large, the effect of suppressing cleaning blade curling can be obtained, but there is a possibility that toner fogging will occur in non-image areas, or that image defects will occur in image areas due to toner or external additives slipping through the cleaning blade.

[0203] The area where the fluid first lubricant is present in the edge area of ​​the cleaning blade can be visually confirmed. The percentage of the total length of the region in the longitudinal direction that the region represents can be determined by measuring the longitudinal length of the region where the first lubricant is present, which is visually confirmed, and calculating the ratio of the region to the total length of the cleaning blade in the longitudinal direction.

[0204] (1.2.5) Method for applying first lubricant having fluidity The timing of application of the first lubricant having fluidity to both longitudinal ends of the cleaning blade may be, for example, such that the first lubricant having fluidity is applied to the cleaning blade in advance, or the first lubricant having fluidity may be applied to the cleaning blade by supplying it from another component within the cleaning device, image forming apparatus, or process cartridge.

[0205] It is preferable not to apply the first lubricant having fluidity to the central portion of the cleaning blade in advance in terms of spreading and uniform lubrication of the first lubricant.

[0206] (Method of applying a first lubricant with fluidity in advance) Examples of methods for applying the first lubricant in advance include dipping, pressing cotton or cloth against the surface, applying with a paintbrush, brush, roller, or the like, and applying with a micropipette or dispenser. Among the above methods, application methods using a micropipette or a dispenser are particularly preferred from the viewpoint of controllability of the amount of lubricant applied.

[0207] (Method of applying a first lubricant having fluidity from another member) The lubricant may be supplied from a lubricant supplying member in contact with the cleaning blade, or from the lubricant supplying member via a member in contact with the cleaning blade.

[0208] (1.2.6) Second Lubricant In the present invention, the "second lubricant" refers to a lubricant that is provided as standard in an image forming apparatus, and is supplied to the surface of the photoreceptor (by application with a lubricant application brush or by external addition of lubricant to toner), and the lubricant on the photoreceptor is transferred to the cleaning blade. The lubricant is chemically different in type from the first lubricant having fluidity according to the present invention, and refers to a lubricant supplied from another member to the central portion of the cleaning blade in the longitudinal direction. The presence of the second lubricant in the central portion improves the lubricity of the surface of the cleaning blade.

[0209] It is preferable that the cleaning blade according to the present invention has a region in the longitudinal center where a second lubricant different from the first lubricant present in the regions at both ends is present, from the viewpoint of reducing wear between the image carrier and the cleaning blade and improving durability.

[0210] The type of the second lubricant is not particularly limited and can be selected appropriately from known lubricants, but solid lubricants are particularly preferred, and those containing fatty acid metal salts are preferred. The solid lubricant can be applied by bringing a lubricant application brush into contact with the image carrier in the image forming apparatus and driving the brush in accordance with the driving of the image carrier.

[0211] The fatty acid metal salt is preferably a metal salt of a saturated or unsaturated fatty acid having 10 or more carbon atoms, and examples thereof include zinc laurate, barium stearate, lead stearate, iron stearate, nickel stearate, cobalt stearate, copper stearate, strontium stearate, calcium stearate, cadmium stearate, magnesium stearate, zinc stearate, aluminum stearate, indium stearate, potassium stearate, lithium stearate, sodium stearate, zinc oleate, magnesium oleate, iron oleate, cobalt oleate, copper oleate, lead oleate, manganese oleate, aluminum oleate, zinc palmitate, cobalt palmitate, lead palmitate, magnesium palmitate, aluminum palmitate, calcium palmitate, lead caprate, zinc linoleate, cobalt linoleate, calcium linoleate, zinc ricinoleate, and cadmium ricinoleate. Among these, zinc stearate is particularly preferred from the viewpoints of its effect as a second lubricant (improving the lubricity of the surface of the cleaning blade), ease of availability, cost, and the like.

[0212] (1.2.7) Cleaning Blade Configuration The cleaning blade according to the present invention is mainly composed of a rubber material and a support member. The rubber material does not need to be the same material, and the blade may be made of two layers, for example, a contact layer that forms the edge portion and a support layer. In the case of a two-layer structure, for example, the material of the support layer may have a lower permanent deformation rate than the material of the contact layer in order to prevent settling.

[0213] (rubber materials) The rubber material is preferably urethane rubber, ie, polyurethane, from the viewpoint of abrasion resistance and moldability. The polyurethane may be obtained by using, for example, polyol and polyisocyanate as raw materials and reacting them with a crosslinking agent as needed. The polyurethane may have a single layer structure, or may have a multi-layer structure in which, for example, the polyurethane of the base layer and the polyurethane of the edge layer are different and these are laminated.

[0214] [Polyol] As the polyol, polyether polyol, polyester polyol, polycarbonate polyol, and polycaprolactone polyol can be used. More specifically, examples include polyethylene adipate, polybutylene adipate, and polyethylene butylene adipate, but other materials may also be used. The polyols may be used alone or in combination of two or more.

[0215] [Isocyanate] Examples of isocyanates include tolylene diisocyanate, 4,4-diphenylmethane diisocyanate (MDI), hexamethylene diisocyanate, isophorone diisocyanate, 1,4-cyclohexane diisocyanate, and isomers thereof, but other isocyanates may also be used. The isocyanates may be used alone or in combination of two or more.

[0216] [Crosslinking agent] The crosslinking agent is preferably a mixture of a low molecular weight diol and a low molecular weight triol. Examples of low molecular weight diols include 1,4-butanediol, ethylene glycol, diethylene glycol, 1,6-hexanediol, and neopentyl glycol, but other diols may also be used. Examples of low molecular weight triols include trimethylolpropane and triisopropanolamine, but other triols may also be used.

[0217] 〔hardness〕 The rubber hardness of the cleaning blade according to the present invention is preferably within the range of 65 to 85° in terms of the hardness value defined by JIS-A. If the rubber hardness is 65° or more, the blade will not be easily retracted and the wedge angle will not become too small. Furthermore, if the rubber hardness is 85° or less, the surface pressure will not be too high and the abrasive force will not be too strong, and the fatty acid metal salt will not be easily removed, so that a sufficient lubricating effect can be obtained.

[0218] (support member) The support member is not particularly limited, and any conventionally known member can be used, including, for example, those made of rigid metal, elastic metal, plastic, ceramic, and the like. Among these, rigid metals are preferred.

[0219] (Conditions of contact) The contact force of the cleaning blade according to the present invention is preferably within the range of 12 to 30 (N / m) from the viewpoint of preventing incomplete wiping and curling.

[0220] (1.3) Manufacturing method of image carrier The image carrier according to the present invention can be manufactured by a process of forming a surface layer on the outer peripheral surface of a photosensitive layer provided on a conductive support by curing a surface layer-forming composition containing a binder resin composed of a polymer of a curable monomer (polymerizable compound). A method for manufacturing a photosensitive member, which is a main image carrier, will be described below.

[0221] Specifically, for example, by going through the following steps, an image carrier can be produced in which an intermediate layer, a photosensitive layer (specifically, a charge generating layer and a charge transport layer), and a surface layer are laminated in this order on a conductive support.

[0222] (Outline of manufacturing method of image carrier (photoreceptor)) [Step 1: Formation of intermediate layer] A process of applying a coating liquid for forming an intermediate layer to the outer peripheral surface of a conductive support and drying the coating liquid to form an intermediate layer.

[0223] [Step 2: Formation of Charge Generation Layer] A process of forming a charge generating layer by applying a coating liquid for forming a charge generating layer to the outer peripheral surface of the intermediate layer formed on the conductive support and drying the coating liquid.

[0224] [Step 3: Formation of Charge Transport Layer] A process of forming a charge transport layer by applying a coating liquid for forming the charge transport layer to the outer peripheral surface of the charge generating layer formed on the intermediate layer and drying it.

[0225] [Step 4: Formation of surface layer] A process in which a coating liquid for forming a surface protection (a surface layer-forming composition) is applied to the outer peripheral surface of the charge transport layer formed on the charge generation layer to form a coating film, and the coating film is cured to form a surface layer.

[0226] (Details of the manufacturing method of the image carrier (photoreceptor)) [Step 1: Formation of intermediate layer] In this step (1), a binder resin for the intermediate layer is dissolved in a solvent to prepare a coating liquid for forming the intermediate layer, and inorganic particles (e.g., metal oxide particles, etc.) are dispersed as necessary.The coating liquid for forming the intermediate layer is then applied to a conductive support to a certain thickness to form a coating film, and the coating film is dried to form the intermediate layer.

[0227] The means for dispersing the metal oxide particles in the coating liquid for forming the intermediate layer is not particularly limited, and for example, an ultrasonic disperser, a ball mill, a sand mill, a homomixer, or the like can be used. Examples of methods for applying the coating solution for forming the intermediate layer include known methods such as dip coating, spray coating, spinner coating, bead coating, blade coating, beam coating, slide hopper method, and circular slide hopper method. The method for drying the coating film can be appropriately selected depending on the type of solvent and the thickness of the coating film, but heat drying is preferred.

[0228] The solvent used in the step of forming the intermediate layer is preferably one that can disperse the metal oxide particles well and dissolve the binder resin for the intermediate layer. In the process of forming the intermediate layer, when an alcohol-soluble polyamide resin is used as the binder resin for the intermediate layer, alcohols having 1 to 4 carbon atoms such as methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, t-butanol, and sec-butanol are preferred as they have excellent solubility and coating performance for the polyamide resin. In order to improve storage stability and particle dispersibility, co-solvents that can be used in combination with the above solvents and that provide favorable effects include benzyl alcohol, toluene, methylene chloride, cyclohexanone, and tetrahydrofuran.

[0229] The concentration of the binder resin for the intermediate layer in the coating solution for forming the intermediate layer is appropriately selected according to the thickness of the intermediate layer and the production speed.

[0230] [Step 2: Formation of Charge Generation Layer] In this step (2), a coating liquid for forming the charge generation layer is prepared by dispersing a charge generation material in a solution in which a binder resin for the charge generation layer is dissolved in a solvent, and the coating liquid for forming the charge generation layer is applied to a certain thickness on the intermediate layer to form a coating film, and the coating film is dried to form the charge generation layer.

[0231] The means for dispersing the charge generating material in the coating liquid for forming the charge generating layer is not particularly limited, and for example, an ultrasonic disperser, a ball mill, a sand mill, a homomixer, or the like can be used. Examples of methods for applying the coating liquid for forming the charge generating layer include known methods such as dip coating, spray coating, spinner coating, bead coating, blade coating, beam coating, slide hopper coating, and circular slide hopper coating. The method for drying the coating film can be appropriately selected depending on the type of solvent and the thickness of the coating film, but heat drying is preferred.

[0232] The solvent used to form the charge generating layer is not particularly limited, and examples thereof include toluene, xylene, methylene chloride, 1,2-dichloroethane, methyl ethyl ketone, cyclohexane, ethyl acetate, t-butyl acetate, methanol, ethanol, propanol, butanol, methyl cellosolve, 4-methoxy-4-methyl-2-pentanone, ethyl cellosolve, tetrahydrofuran, 1,4-dioxane, 1,3-dioxolane, pyridine, and diethylamine.

[0233] [Step 3: Formation of Charge Transport Layer] In this step (3), a coating liquid for forming a charge transport layer is prepared by dissolving a binder resin for the charge transport layer and a charge transport material in a solvent, and the coating liquid for forming the charge transport layer is applied to a certain thickness on the charge generation layer to form a coating film, and the coating film is dried to form the charge transport layer.

[0234] Examples of methods for applying the coating solution for forming the charge transport layer include known methods such as dip coating, spray coating, spinner coating, bead coating, blade coating, beam coating, slide hopper coating, and circular slide hopper coating. The method for drying the coating film can be appropriately selected depending on the type of solvent and the thickness of the coating film, but heat drying is preferred.

[0235] The solvent used in forming the charge transport layer is not particularly limited, and examples thereof include toluene, xylene, methylene chloride, 1,2-dichloroethane, methyl ethyl ketone, cyclohexanone, ethyl acetate, butyl acetate, methanol, ethanol, propanol, butanol, tetrahydrofuran, 1,4-dioxane, 1,3-dioxolane, pyridine, and diethylamine.

[0236] [Step 4: Formation of surface layer] In this step (4), a curable monomer (polymerizable compound), a polymerization initiator (radical polymerization initiator), and other components as necessary are added to a solvent to prepare a composition for forming a surface layer, and this composition for forming a surface layer is used as a coating liquid and applied to the outer surface of the charge transport layer formed in step (3) to form a coating film. The resulting coating film is then irradiated with actinic rays to polymerize and harden the curable monomer (polymerizable compound) component in the coating film, thereby forming a surface layer.

[0237] The curable monomer (polymerizable compound) used in preparing the surface layer-forming composition may be oligomerized.

[0238] As the solvent constituting the surface layer forming composition, a solvent capable of dissolving or dispersing the curable monomer (polymerizable compound) is used.

[0239] Specific examples include methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butanol, t-butanol, sec-butanol, benzyl alcohol, toluene, xylene, methylene chloride, methyl ethyl ketone, cyclohexane, ethyl acetate, butyl acetate, methyl cellosolve, ethyl cellosolve, tetrahydrofuran, 1,4-dioxane, 1,3-dioxolane, pyridine, and diethylamine.

[0240] Examples of methods for applying the surface layer-forming composition include known methods such as dip coating, spray coating, spinner coating, bead coating, blade coating, beam coating, slide hopper method, and circular slide hopper method. Among these, the circular slide hopper method is preferred.

[0241] Examples of methods for curing a curable monomer (polymerizable compound) include a method in which a polymerization reaction is caused by electron beam cleavage to cause curing, and a method in which a radical polymerization initiator is added and then irradiated with actinic rays such as electron beams and ultraviolet rays to cause a polymerization reaction with light or heat to cause curing.

[0242] As the radical polymerization initiator, either a photopolymerization initiator or a thermal polymerization initiator can be used, and a photopolymerization initiator and a thermal polymerization initiator can also be used in combination. The photopolymerization initiator and the thermal polymerization initiator may be used alone or in combination of two or more.

[0243] As the polymerization initiator (radical polymerization initiator), a photopolymerization initiator is preferred, and among these, an alkylphenone-based compound or a phosphine oxide-based compound is preferred. In particular, compounds having an α-hydroxyacetophenone structure or an acylphosphine oxide structure are preferred.

[0244] Specific examples of the compound having an acylphosphine oxide structure (acylphosphine oxide-based compound) used as a photopolymerization initiator include the above-mentioned exemplary compounds (P1) and (P2).

[0245] The proportion of the polymerization initiator added is preferably within a range of 0.1 to 20 parts by mass, more preferably within a range of 0.5 to 10 parts by mass, relative to 100 parts by mass of the curable monomer.

[0246] As actinic rays, ultraviolet rays and electron beams are preferred, and from the viewpoint of ease of use, ultraviolet rays are particularly preferred.

[0247] When a coating film containing a polymerization initiator is irradiated with actinic rays, radicals are generated in the coating film, causing a polymerization reaction to proceed, and crosslinking bonds are formed by inter- and intra-molecular crosslinking reactions, causing curing to proceed, thereby producing a cured resin (crosslinked cured resin).

[0248] Any light source that generates ultraviolet light can be used as the ultraviolet light source without limitation, and examples thereof include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, carbon arc lamps, metal halide lamps, xenon lamps, and flash (pulse) xenon lamps.

[0249] The UV irradiation conditions vary depending on the type of UV light source, but the exposure dose of actinic rays is usually 5 to 500 mJ / cm 2 in the range of 5 to 100 mJ / cm 2 The lamp power is preferably in the range of 0.1 to 5 kW, and particularly preferably in the range of 0.5 to 3 kW.

[0250] Any electron beam irradiation device can be used as the electron beam source without any particular restrictions, and generally, an electron beam accelerator for electron beam irradiation of the curtain beam type, which is relatively inexpensive and can provide a large output, is preferably used. The acceleration voltage during electron beam irradiation is preferably within the range of 100 to 300 kV. The absorbed dose is preferably within the range of 0.5 to 10 Mrad.

[0251] The irradiation time for obtaining the amount of actinic radiation required for the curing treatment is preferably 0.1 seconds to 10 minutes, and from the viewpoint of work efficiency, more preferably 0.1 seconds to 5 minutes.

[0252] In the step of forming this surface layer, drying can be carried out before, after, or during irradiation with actinic rays, and the timing of drying can be appropriately selected by combining these.

[0253] According to the image carrier of the present invention as described above, the surface layer contains a cured resin, and therefore high durability is obtained due to the action of the cured resin, thereby reducing the amount of wear, and low friction characteristics are maintained over a long period of use, resulting in good cleaning properties.

[0254] The image carrier according to the present invention can be used in a general electrophotographic image forming apparatus, and can be particularly suitably used in an image forming apparatus in which the image carrier is charged by an AC charging roller system, i.e., an AC charging roller system image forming apparatus in which the image carrier is charged by a charging roller that is provided in contact with the image carrier and to which an AC voltage is applied.

[0255] (1.4) Cleaning Blade Manufacturing Method The cleaning blade of the present invention is a cleaning blade used in an image forming apparatus having a mechanism for cleaning the surface of an image carrier, and is characterized in that the cleaning blade has an area at both ends in the longitudinal direction where a first lubricant having fluidity is present.

[0256] The cleaning blade according to the present invention is produced by first preparing a rubber sheet as described below, and then applying a fluid first lubricant to the cleaning blade formed by a known polyurethane forming method.

[0257] (1.4.1) Rubber material: Preparation of rubber sheet The rubber sheet of the cleaning blade according to the present invention is produced by a known polyurethane molding method, for example, as follows. (Prepolymer formation) First, the polyol and isocyanate are dehydrated, and then mixed and reacted at a temperature in the range of 70 to 140° C. for 10 to 120 minutes to form a prepolymer.

[0258] (Addition of cross-linking agent) Thereafter, a crosslinking agent and the like are added to the prepolymer. The crosslinking agent is preferably a mixture of a low molecular weight diol and a low molecular weight triol.

[0259] (Prepolymer hardening) After adding a crosslinking agent to the prepolymer, the mixture is poured into a mold of a centrifugal molding machine preheated to, for example, 150°C, and cured for 5 to 10 minutes to produce a rubber sheet. The thickness of the sheet is, for example, within the range of 0.6 to 2.0 mm.

[0260] (1.4.2) Rubber material: Cutting and gluing rubber sheets The rubber sheet produced by the above process is cut vertically with a blade to a size of 340 mm x 14.0 mm. Thereafter, the blade is heat-bonded to a metal plate with a bonding margin of 4 mm using a thermosetting adhesive to prepare a cleaning blade with a free length of 10.0 mm.

[0261] (1.4.3) Application of a fluid first lubricant A first lubricant having fluidity is applied to both longitudinal ends of the cleaning blade obtained by the above process. The application method is as described above.

[0262] (1.5) Overview of the configuration example of the image forming device FIG. 4 is a cross-sectional view showing the structure of a tandem image forming apparatus as an example of an image forming apparatus equipped with an image carrier and a cleaning blade according to the present invention. The image forming apparatus 100 includes a charging means for charging a photosensitive member with a charging device, an exposure means for forming an electrostatic latent image by image exposure, a developing means for developing the toner image using a developing device to make it visible, a transfer means for transferring the toner image onto a transfer medium such as paper or a transfer belt, and a charge removal means.

[0263] The toner image transferred directly onto the copy paper and the toner image transferred onto the paper via a transfer medium such as a transfer belt are fixed to the copy paper by a fixing process such as a contact heating method, thereby forming a visible image.

[0264] After the transfer, the toner remaining on the photosensitive member (transfer residual toner) is removed by a cleaning device equipped with a cleaning blade or the like.

[0265] Image forming apparatus 100 may be configured by combining components such as a photosensitive member, developing means, and cleaning device together as an image forming unit, and this image forming unit may be configured to be detachable from the main body of the apparatus. In addition, at least one of the charging means, exposure means, developing means, transfer means and cleaning means may be integrally supported together with the photosensitive member to form an image forming unit, which may be a single image forming unit that is detachable from the main body of the apparatus, and may be configured to be detachable using guide means such as rails on the main body of the apparatus.

[0266] (Main components of the image forming device) The image forming apparatus 100 shown in FIG. 4 has an apparatus main body A and a document image reading device SC provided on top of the apparatus main body A. The image forming apparatus 100 comprises four image forming sections (image forming units) 10Y, 10M, 10C, and 10Bk, an endless belt-shaped intermediate transfer unit 7, a paper feed cassette 20, a paper feed section 21, a registration roller 23, and a fixing section 24.

[0267] (1.5.1) Image forming unit The image forming unit is detachable from the image forming apparatus main body, and is characterized in that the image carrier and a mechanism for cleaning the surface of the image carrier are integrated together, and the image forming unit is equipped with the cleaning device. This makes it possible to achieve both resistance to curling of the cleaning blade and cleaning performance even during high-speed image formation.

[0268] (Configuration of image forming unit) The four image forming units 10Y, 10M, 10C, and 10Bk are composed of photoconductors 1Y, 1M, 1C, and 1Bk at the center, charging means 2Y, 2M, 2C, and 2Bk, exposure means 3Y, 3M, 3C, and 3Bk, rotating developing means 4Y, 4M, 4C, and 4Bk, primary transfer rollers 5Y, 5M, 5C, and 5Bk as primary transfer means, and cleaning devices 6Y, 6M, 6C, and 6Bk that clean the photoconductors 1Y, 1M, 1C, and 1Bk.

[0269] The images of each color formed by the image forming units 10Y, 10M, 10C, and 10Bk are transferred successively onto a rotating endless belt-like intermediate transfer body 70 by primary transfer rollers 5Y, 5M, 5C, and 5Bk as primary transfer means, to form a composite color image. The transfer material (image support carrying the fixed final image: for example, plain paper, transparent sheet, etc.) P stored in the paper feed cassette 20 is fed by the paper feed section 21, and is transported via a plurality of intermediate rollers 22A, 22B, 22C, 22D and a resist roller 23 to a secondary transfer roller 5b as a secondary transfer means, where the color image is transferred all at once by secondary transfer onto the transfer material P. The transfer material P onto which the color image has been transferred is subjected to a fixing process by a fixing section 24, and is then sandwiched between paper discharge rollers 25 and placed on a paper discharge tray 26 outside the apparatus. Here, the intermediate transfer body onto which the image formed on the photosensitive member is transferred, the transfer material, and other transfer supports for the toner image are collectively called transfer media.

[0270] On the other hand, after a color image is transferred onto the transfer material P by the secondary transfer roller 5b as a secondary transfer means, the endless belt-shaped intermediate transfer body 70 from which the transfer material P is separated by curvature has residual toner removed by the cleaning device 6b.

[0271] During the image forming process, the primary transfer roller 5Bk is always in contact with the photosensitive member 1Bk. The other primary transfer rollers 5Y, 5M and 5C come into contact with the corresponding photoreceptors 1Y, 1M and 1C only during color image formation.

[0272] The secondary transfer roller 5b comes into contact with the endless belt-like intermediate transfer member 70 only when the transfer material P passes therethrough and secondary transfer is performed.

[0273] Furthermore, the housing 8 can be pulled out from the device main body A via support rails 82L and 82R.

[0274] The housing 8 comprises image forming sections 10Y, 10M, 10C and 10Bk, and an intermediate transfer unit 7 in the form of an endless belt.

[0275] The image forming units 10Y, 10M, 10C, and 10Bk are arranged in a vertical column. An endless belt-shaped intermediate transfer unit 7 is disposed on the left side of the photosensitive members 1Y, 1M, 1C, and 1Bk in the drawing. The endless belt type intermediate transfer unit 7 comprises an endless belt type intermediate transfer member 70 which can rotate around rollers 71, 72, 73 and 74, primary transfer rollers 5Y, 5M, 5C and 5Bk, and a cleaning device 6b.

[0276] Image forming units (process cartridges) 10Y, 10M, 10C, and 10Bk have the same configuration except for the different colors of toner they contain: yellow (Y), magenta (M), cyan (C), and black (Bk), respectively. Therefore, the image forming unit (process cartridge) 10Y will be described in detail below as an example.

[0277] The image forming unit (process cartridge) 10Y has a charging means 2Y, an exposure means 3Y, a developing means 4Y, and a cleaning device 6Y around the photosensitive member 1Y, which is an image forming body, and forms a yellow (Y) toner image on the photosensitive member 1Y.

[0278] The charging means 2Y is a means for uniformly charging the surface of the photoreceptor 1Y to a negative polarity. As the charging means 2Y, for example, a corona discharge type charger is used.

[0279] The exposure means 3Y is a means for exposing the photoreceptor 1Y, to which a uniform potential has been applied by the charging means 2Y, based on an image signal (yellow), to form an electrostatic latent image corresponding to the yellow image. The exposure means 3Y may be configured with an LED in which light emitting elements are arranged in an array in the axial direction of the photosensitive member 1Y and an imaging element, or may be a laser optical system.

[0280] The developing means 4Y comprises, for example, a developing sleeve (not shown) that contains a magnet and rotates while holding developer, a photosensitive member, and a voltage application device that applies a DC and / or AC bias voltage between the developing sleeve.

[0281] The developing means 4Y is composed of, for example, a developing sleeve that incorporates a magnet and rotates while holding a developer, and a voltage application device that applies a DC and / or AC bias voltage between the developing sleeve and the photosensitive member.

[0282] The fixing section 24 may be, for example, a heat roller fixing type that is composed of a heating roller equipped with a heat source inside and a pressure roller that is pressed against the heating roller to form a fixing nip section.

[0283] (Main parts of the image forming unit) FIG. 5 is a diagram illustrating an example of the configuration of a main part of the image forming unit shown in FIG. The image forming units 10Y, 10M, 10C, and 10Bk are configured similarly except for the colors of the toner images formed on the photoreceptors 1Y, 1M, 1C, and 1Bk. Therefore, the image forming unit 10Y will be described in detail as an example, and a description of the image forming units 10M, 10C, and 10Bk will be omitted.

[0284] [Cleaning device] The cleaning device provided in the image forming apparatus of the present invention has a mechanism for cleaning the surface of the image carrier, and can achieve both resistance to curling of the cleaning blade and cleaning performance even during high-speed image formation.

[0285] Furthermore, the cleaning device is characterized by including the cleaning blade according to the present invention, but may be configured to include various parts or members depending on the purpose. For example, it is preferable to provide a lubricant, a lubricant supply means, and a lubricant application means including a lubricant application brush roller. It is also preferable to provide a developer recovery container for storing developer containing toner etc. removed by the cleaning device.

[0286] There are two types of cleaning devices, for example, a "cleaning device 6b" provided in the unit of the "endless belt-like intermediate transfer body 70" described later, and a "cleaning device 6Y" provided in the "image forming unit (process cartridge) 10Y", and the cleaning blades provided in both devices may be the same. The cleaning device 6Y includes a cleaning blade. A brush roller may be provided upstream of the cleaning blade.

[0287] The lubricant supplying section 116Y supplies the second lubricant described above to the surface of the photoreceptor 1Y, and supplies (applies) it to a cleaning blade provided in a cleaning device via the photoreceptor 1Y. The lubricant supply unit 116Y is provided, for example, downstream of the primary transfer roller 5Y and upstream of the cleaning device 6Y. The lubricant supply unit 116Y may be located at another position, for example, downstream of the cleaning device 6Y. The lubricant supply unit 116Y includes a brush roller 121, a solid second lubricant 122, and a pressure spring 123.

[0288] The brush roller 121 applies the second lubricant 122 to the surface of the photoreceptor 1Y. The brush roller 121 is formed by, for example, forming a pile fabric into a ribbon-like fabric by weaving bundles of fibers into a base fabric as pile yarns, and then spirally winding the fabric around a metal shaft with the raised surface facing outward and gluing it together. In this brush roller 121, brush fibers made of resin such as polypropylene are densely embedded in a long woven fabric, and this woven fabric is provided on the circumferential surface of the roller base.

[0289] It is preferable to use straight bristles for the brush bristles in terms of the ability to apply the second lubricant. The straight hair type has the hair brushed perpendicular to the metal shaft. The thread used for the brush bristles is preferably a filament thread, and examples of the material include polyamides such as 6-nylon and 12-nylon, polyester, acrylic resin, vinylon, and other synthetic resins, and metals such as carbon and nickel may be kneaded into the thread to increase conductivity. The thickness of the brush fibers is, for example, 3 to 7 denier, the hair length of the brush fibers is, for example, in the range of 2 to 5 mm, and the electrical resistivity of the brush fibers is, for example, 1×10 10 Ω or less, Young's modulus of brush fiber is 4900~9800N / mm 2 Within this range, the planting density of the brush fibers (number of brush fibers per unit area) is, for example, 50 to 200,000 fibers / square inch (50 to 200k fibers / inch 2 ) is preferred. The amount of penetration of the brush roller 121 into the photosensitive element 1Y is preferably within the range of 0.5 to 1.5 mm. The rotation speed of the brush roller 121 is, for example, within a range of 0.3 to 1.5 in terms of the peripheral speed ratio to the photosensitive member 1Y. The rotation direction of the brush roller 121 may be either the same as or opposite to the rotation direction of the photosensitive member 1Y.

[0290] The pressure spring 123 presses the brush roller 121 against the photosensitive element 1Y via the second lubricant 122. For example, the pressure spring 123 presses the second lubricant 122 so that the pressing force of the brush roller 121 against the photosensitive element 1Y is within a range of 0.5 to 1.0 N.

[0291] In the lubricant supply unit 116Y, for example, the pressing force of the second lubricant 122 against the brush roller 121 and the rotation speed of the brush roller 121 are adjusted in order to adjust the consumption amount of the second lubricant 122 within a desired range. For example, the amount of second lubricant 122 consumed per 1 km of cumulative length of the surface of the photoreceptor 1Y is preferably within a range of 0.04 to 0.27 g / km, and more preferably within a range of 0.04 to 0.15 g / km.

[0292] The above describes the lubricant supply unit 116Y that applies a solid second lubricant 122 to the surface of the photosensitive member 1Y using a brush roller 121, but the lubricant supply unit 116Y may also externally add a fine powder lubricant to the toner base particles when producing the toner. In the lubricant supplying section 116Y, the second lubricant is supplied to the surface of the photoreceptor 1Y by the action of the developing electric field formed in the developing section 4Y.

[0293] The cleaning device 6Y includes a cleaning blade 61 and a screw 62. The cleaning blade 61 is a flat plate-shaped member that comes into contact with the surface of the photoreceptor 1Y to clean the surface of the photoreceptor 1Y. The cleaning blade 61 has a flat plate shape extending in the direction of the rotation axis of the photoreceptor 1Y. The cleaning blade 61 abuts against the photoreceptor 1Y in the counter direction to the rotation direction of the photoreceptor 1Y. The cleaning blade 61 presses against the surface of the photoreceptor 1Y, thereby scraping off toner (residual toner) remaining on the surface of the photoreceptor 1Y after transfer. The remaining toner and the like scraped off from the surface of the photoreceptor 1Y is discharged to the outside of the image forming apparatus 100 by, for example, a screw 62. Together with the cleaning blade 61, a brush roller 121 may scrape off the remaining toner on the surface of the photoreceptor 1Y.

[0294] It is preferable that the cleaning blade 61 maintains stable contact with the surface of the photoreceptor 1Y even when the environment in which it is used, such as temperature, humidity, and frequency, fluctuates. This prevents the cleaning performance from decreasing, making it easier to maintain the desired cleaning performance.

[0295] [Endless belt type intermediate transfer unit] The endless belt-shaped intermediate transfer body unit 7 has an endless belt-shaped intermediate transfer body 70 as a second image carrier in the form of a semiconductive endless belt that is wound around, for example, a plurality of rollers and rotatably supported, and also has a plurality of rollers 71 to 74 and a cleaning section 6b. The intermediate transfer member 70 is wound around and supported by rollers 71 to 74. The intermediate transfer member 70 rotates, for example, clockwise in accordance with the rotation of the rollers 71 to 74. The toner images (full color) transferred from the primary transfer rollers 5Y, 5M, 5C, and 5Bk to the intermediate transfer body 70 are transferred onto, for example, paper P at the secondary transfer section 5b. The secondary transfer unit 5b is provided at a position facing the roller 74, for example. The cleaning section 6b cleans the surface of the intermediate transfer body 70 after transfer to remove residual toner and the like. The cleaning unit 6b has, for example, a blade that comes into contact with the surface of the intermediate transfer body .

[0296] The image forming units 10Y, 10M, 10C, and 10Bk and the endless belt-shaped intermediate transfer unit 7 are housed in, for example, a housing 8. The housing 8 is configured so as to be able to be pulled out from the apparatus main body A via support rails 82L and 82R.

[0297] [Paper cassette] A plurality of sheets of paper P are stacked in the paper feed cassette 20. The image forming apparatus 100 is provided with, for example, a plurality of paper feed cassettes 20.

[0298] [Paper feed section] The paper feed unit 21 sends out the topmost paper sheet P from among the paper sheets P stacked in the paper feed cassette 20, for example, to a paper transport path. The paper feed unit 21 includes, for example, a transport roller. The paper feed unit 21 may be an air suction type paper feed unit.

[0299] A plurality of intermediate rollers 22A, 22B, 22C, and 22D are provided in the paper transport path between the paper feed unit 21 and the registration rollers 23. Each of the intermediate rollers 22A, 22B, 22C, and 22D is a pair of transport rollers. For example, from the paper feed unit 21 side, the intermediate rollers are arranged in the order of intermediate roller 22A, intermediate roller 22B, intermediate roller 22C, and intermediate roller 22D.

[0300] [Registration Roller] The registration rollers 23 are provided on the paper transport path between the intermediate roller 22D and the secondary transfer unit 5b. The registration rollers 23 are configured by a roller pair made up of, for example, a registration drive roller and a registration driven roller.

[0301] [Fixing section] The fixing unit 24 is, for example, a fixing unit of a heat roller fixing type, and includes a heating roller and a pressure roller. The heating roller includes a heat source therein. The pressure roller is provided in pressure contact with the heating roller, and a fixing nip is formed between the heating roller and the pressure roller.

[0302] In the above embodiment, the image forming apparatus 100 is a color printer, but it may also be a monochrome printer, a copier, a multifunction machine, or the like.

[0303] Furthermore, the image forming apparatus 100 may further be provided with a lubricant removal unit (not shown) that removes the second lubricant 122 from the surfaces of the photoreceptors 1Y, 1M, 1C, and 1Bk, as necessary. For example, in the rotation direction of the photosensitive member 1Y, a lubricant supply unit 116Y may be provided downstream of the cleaning unit 6Y and upstream of the charging unit 2Y, and a lubricant removal unit may be further arranged downstream of the lubricant supply unit 116Y and upstream of the charging unit 2Y.

[0304] The lubricant removal section includes, for example, a removal member. For example, this removing member comes into contact with the surface of the photosensitive member 1Y, and the second lubricant 122 is removed by mechanical action. The removal member may be, for example, a brush roller or a foam roller.

[0305] 2. Image forming method (2.1) Overview of image formation method The image forming method of the present invention is an image forming method using a toner for developing an electrostatic latent image, characterized in that an image carrier is used in the electrostatic latent image forming step or the toner image transfer step, and the image carrier contains a binder resin consisting of at least a polymer of a curable monomer in the surface layer of the image carrier, and the surface of the image carrier is cleaned with a cleaning blade having areas in which a first lubricant having fluidity is present at both ends in the longitudinal direction.

[0306] In addition, it is preferable to use the cleaning blade having a region in the center in the longitudinal direction where a second lubricant different from the first lubricant present in the regions at both ends is present, from the viewpoint of reducing wear between the image carrier and the cleaning blade and improving durability.

[0307] The image forming method of the present invention can be used in various known image forming methods and apparatuses, for example, electrophotographic systems. Specifically, it can be used in a monochrome image forming method and a full-color image forming method and apparatus.

[0308] In the full-color image forming method, any image forming method can be used, such as a four-cycle image forming method consisting of four types of color developing devices for yellow, magenta, cyan, and black, and one image carrier, or a tandem image forming method in which image forming units having color developing devices and image carriers for each color are installed, one for each color.

[0309] Specifically, the image forming method of the present invention uses an image carrier according to the present invention produced by the above-described method, charges the image carrier with a charging device (charging step), and exposes the image carrier to light (exposing step) to form an electrostatic latent image, which is then developed with a developing device (developing step) to form a visible toner image.

[0310] This toner image is transferred onto a transfer medium such as copy paper or a transfer belt (transfer step), and then goes through a charge removal step before the next image formation cycle is carried out.

[0311] The toner image transferred onto a transfer medium such as a transfer belt is then transferred onto copy paper, and the toner image transferred onto the copy paper is fixed to the copy paper (fixing process) using a fixing process such as a contact heating method, thereby obtaining a visible image.

[0312] After the transfer step, the toner remaining on the image carrier (residual toner after transfer) is removed (cleaning step) by a rubber blade or the like. This cleaning step may be performed either before or after the charge removal step, but if the charge removal step is performed by light irradiation, it is preferable to perform the cleaning step after the cleaning step, since the toner remaining on the image carrier will not interfere with the absorption of the charge removal light, allowing for more effective charge removal.

[0313] In the static elimination step, either alternating current static elimination (AC static elimination) or optical static elimination may be used, but AC static elimination requires the installation of an AC power source, which poses problems such as space issues and the need for a large-scale device, so optical static elimination is preferred.

[0314] (2.2) Image forming process Next, a specific image forming method will be described using an image forming apparatus.

[0315] In the present invention, the image forming apparatus uses the image carrier of the present invention and includes a charging means for charging the image carrier with a charging device, an exposure means for forming an electrostatic latent image by image exposure, a developing means for developing the toner image using a developing device to make it visible and obtain a toner image, a transfer means for transferring the toner image onto a transfer medium such as paper or a transfer belt, and a discharging means.The toner image transferred directly onto copy paper and the toner image transferred onto paper via a transfer medium such as a transfer belt are fixed to the copy paper by a fixing process such as a contact heating method to obtain a visible image. After the transfer, the toner remaining on the image carrier (transfer residual toner) is removed by a cleaning device such as a cleaning blade.

[0316] The image forming apparatus of the present invention uses the image carriers of the present invention described above as the photoreceptors 1Y, 1M, 1C, and 1Bk, for example.

[0317] The image forming units 10Y, 10M, 10C, and 10Bk have the same configuration except that the toner colors they contain are different, namely yellow (Y), magenta (M), cyan (C), and black (Bk), respectively. Therefore, the image forming unit 10Y will be described in detail below as an example.

[0318] The image forming unit 10Y has a charging means 2Y, an exposure means 3Y, a developing means 4Y, and a cleaning device 6Y around a photoreceptor 1Y, which is an image forming body, and forms a yellow (Y) toner image on the photoreceptor 1Y.

[0319] (Charging means) The charging means 2Y is a means for uniformly charging the surface of the photoreceptor 1Y to a negative polarity. As the charging means 2Y, for example, a corona discharge type charger is used.

[0320] (Exposure means) The exposure means 3Y is a means for exposing the photoreceptor 1Y, to which a uniform potential has been applied by the charging means 2Y, based on an image signal (yellow), to form an electrostatic latent image corresponding to the yellow image. The exposure means 3Y may be configured with an LED in which light emitting elements are arranged in an array in the axial direction of the photosensitive member 1Y and an imaging element, or may be a laser optical system.

[0321] (Developing means) The developing means 4Y comprises, for example, a developing sleeve (not shown) that has a built-in magnet and rotates while holding developer, an image carrier, and a voltage application device that applies a DC and / or AC bias voltage between the developing sleeve.

[0322] The developing means 4Y is composed of, for example, a developing sleeve that incorporates a magnet and rotates while holding a developer, and a voltage application device that applies a DC and / or AC bias voltage between the developing sleeve and the image carrier.

[0323] (Fixing means) The fixing means 24 may be, for example, a heat roller fixing method that is composed of a heating roller equipped with a heat source inside and a pressure roller that is pressed against the heating roller so as to form a fixing nip portion.

[0324] (cleaning device) The cleaning device 6Y is composed of a cleaning blade. A brush roller may be provided upstream of the cleaning blade. Furthermore, a lubricant supplying means (not shown) for supplying (applying) a lubricant to the surface of the photoreceptor 1Y may be provided. The lubricant supplying means may be provided, for example, downstream of the primary transfer roller 5Y and upstream of the cleaning device 6Y. However, it may be located downstream of the cleaning device 6Y.

[0325] Image forming apparatus 100 may be configured by combining components such as an image carrier, developing means, and cleaning device together as an image forming unit, and this image forming unit may be configured to be detachable from the main body of the apparatus. In addition, at least one of the charging means, exposure means, developing means, transfer means and cleaning device may be integrally supported together with the image carrier to form an image forming unit, which may be a single image forming unit that is detachable from the main body of the apparatus, and may be configured to be detachable using guide means such as rails on the main body of the apparatus.

[0326] The endless belt-shaped intermediate transfer member unit 7 has an endless belt-shaped intermediate transfer member 70 as a second image carrier in the form of a semiconductive endless belt that is wound around a plurality of rollers and rotatably supported.

[0327] The images of each color formed by the image forming units 10Y, 10M, 10C, and 10Bk are transferred successively onto a rotating endless belt-like intermediate transfer body 70 by primary transfer rollers 5Y, 5M, 5C, and 5Bk as primary transfer means, to form a composite color image.

[0328] A transfer material (image support carrying the fixed final image: for example, plain paper, a transparent sheet, etc.) P stored in a paper feed cassette 20 is fed by a paper feed means 21, and is transported via a plurality of intermediate rollers 22A, 22B, 22C, 22D and a resist roller 23 to a secondary transfer roller 5b as a secondary transfer means, where the color image is transferred onto the transfer material P in one go.

[0329] The transfer material P onto which the color image has been transferred is subjected to fixing processing by fixing means 24, and is then sandwiched between paper discharge rollers 25 and placed on a paper discharge tray 26 outside the apparatus. Here, the transfer support for the toner image formed on the image carrier, such as the intermediate transfer body or the transfer material, is collectively called the transfer medium.

[0330] On the other hand, after a color image is transferred onto the transfer material P by the secondary transfer roller 5b as a secondary transfer means, the endless belt-shaped intermediate transfer body 70 from which the transfer material P is separated by curvature has residual toner removed by the cleaning device 6b.

[0331] During the image forming process, the primary transfer roller 5Bk is always in contact with the photosensitive member 1Bk. The other primary transfer rollers 5Y, 5M and 5C come into contact with the corresponding photoreceptors 1Y, 1M and 1C only during color image formation.

[0332] The secondary transfer roller 5b comes into contact with the endless belt-like intermediate transfer member 70 only when the transfer material P passes therethrough and secondary transfer is performed.

[0333] Furthermore, the housing 8 can be pulled out from the device main body A via support rails 82L and 82R.

[0334] The housing 8 comprises image forming sections 10Y, 10M, 10C and 10Bk, and an intermediate transfer unit 7 in the form of an endless belt.

[0335] Image forming units 10Y, 10M, 10C, and 10Bk are arranged in a vertical column. An endless belt-shaped intermediate transfer unit 7 is arranged on the left side of photoreceptors 1Y, 1M, 1C, and 1Bk in the figure. The endless belt type intermediate transfer unit 7 comprises an endless belt type intermediate transfer member 70 which can rotate around rollers 71, 72, 73 and 74, primary transfer rollers 5Y, 5M, 5C and 5Bk, and a cleaning device 6b.

[0336] (2.3) Toner and Developer In the present invention, the "toner base particles" are those that constitute the base of the "toner particles." "Toner base particles" contain at least a binder resin and a colorant, and may contain other components such as a release agent (wax) and a charge control agent as needed. "Toner base particles" are called "toner particles" when external additives are added. "Toner" refers to an aggregate of "toner particles."

[0337] In the present invention, the toner to be applied to the image forming apparatus is not particularly limited, and various known toners can be used.

[0338] As the toner, either pulverized toner or polymerized toner can be used, but from the viewpoint of obtaining high quality images, it is preferable to use polymerized toner.

[0339] The average particle size of the toner is not particularly limited, but it is preferable that the volume-based median size is within the range of 2 to 8 μm. By setting the value in this range, it is possible to further increase the resolution.

[0340] In addition, inorganic particles such as silica and titania having an average particle size of about 10 to 300 nm, abrasives having an average particle size of about 0.2 to 3 μm, etc. may be externally added to the toner base particles in appropriate amounts as external additives.

[0341] When the toner is used as a two-component developer, the carrier may be magnetic particles made of conventionally known materials such as ferromagnetic metals such as iron, alloys of ferromagnetic metals with aluminum and lead, and compounds of ferromagnetic metals such as ferrite and magnetite. Among these, ferrite is particularly preferable.

[0342] As the carrier, it is preferable to use one that is further coated with a resin, or a so-called resin-dispersed carrier in which magnetic particles are dispersed in a resin. The resin composition for coating is not particularly limited, but it is preferable to use, for example, a cyclohexyl methacrylate-methyl methacrylate copolymer.

[0343] The volume-based median diameter of the carrier is preferably within a range of 15 to 100 μm, and more preferably within a range of 25 to 60 μm.

[0344] The concentration of the toner contained in the two-component developer is preferably within the range of 4.0 to 8.0% by mass. [Example]

[0345] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these. In the examples, the terms "parts" and "%" are used, but unless otherwise specified, they represent "parts by mass" or "% by mass."

[0346] [Cleaning blade manufacturing] As described above, a urethane rubber sheet having a thickness of 2.00 mm was produced by the known centrifugal molding method. Next, the sheet was cut vertically with a blade to obtain pieces measuring 340 mm x 14.0 mm.

[0347] A cleaning blade (CL0) with a free length of 10.0 mm was fabricated by heat-bonding it to a metal plate with a bonding margin of 4 mm using a thermosetting adhesive.

[0348] <Preparation of cleaning blade (1)> Demnum (manufactured by Daikin Industries, Ltd.) was applied as a first fluid lubricant to the cleaning blade (CL0) using a cordless electric dispenser "Tofutty MSIC06-01" (manufactured by Icomes Lab Co., Ltd.) in an area of ​​8% or less of the total length in the longitudinal direction from the ends of both ends toward the center, to produce cleaning blade (1).

[0349] <Preparation of cleaning blades (2) to (4) and (6) to (13)> The cleaning blade was produced in the same manner as cleaning blade (1), except that the type of the first lubricant having flowability and the percentage of the total length of the longitudinal direction of the cleaning blade to which the first lubricant was applied from the ends of both ends of the cleaning blade toward the center were as shown in Table I.

[0350] <Preparation of cleaning blade (5)> The cleaning blade (CL0) was dipped in a vat containing Tospearl 120 (manufactured by Momentive Performance Materials Japan, LLC) as a first lubricant having fluidity, and the Tospearl 120 was applied to an area of ​​8% or less of the total length in the longitudinal direction from the ends of both ends toward the center, thereby producing cleaning blade (5).

[0351] <Preparation of cleaning blade (11)> Referring to Example 1 of JP 2010-170157 A, the cleaning blade was impregnated with an appropriate amount of 4,4'-methylenephenyl diisocyanate (4,4'-MDI, manufactured by Tokyo Chemical Industry Co., Ltd.) isocyanate compound, and the isocyanate compound was allowed to come into contact with the blade and then left for 20 minutes to form a hardened treated area in 5% of the edge region.

[0352] <Preparation of cleaning blade (12)> With reference to Example 1 of JP-A 2002-162885, the cleaning blade was dipped in Vegichem Green V140 (a polyamide resin manufactured by Tsuno Foods Industries Co., Ltd.) to form a resin film over 5% of the edge region.

[0353] [Table 1]

[0354] [Production of image carrier (photoreceptor)] A photoreceptor serving as an image bearing member was prepared in the following manner.

[0355] <Preparation of Image Carrier (Photoreceptor) (1)> (Preparation of conductive support) The surface of an aluminum cylinder with a diameter of 30 mm was machined to create a finely roughened conductive support [1].

[0356] (Formation of intermediate layer) A dispersion consisting of 1 part by mass of polyamide resin "CM8000" (manufactured by Toray Industries, Inc.) as a binder resin, 3 parts by mass of titanium oxide microparticles "SMT500SAS" (manufactured by Teika Corporation) as metal oxide particles, and 10 parts by mass of methanol as a solvent was diluted two-fold with methanol, allowed to stand overnight, and then filtered (using a filter; a Rigimesh 5 μm filter manufactured by Nippon Pall Corporation), to prepare a coating solution [1] for forming an intermediate layer. The obtained coating solution for forming an intermediate layer [1] was applied onto a conductive support [1] by dip coating to form an intermediate layer [1] having a dry thickness (layer thickness) of 2 μm.

[0357] (Formation of Charge Generation Layer) 20 parts by weight of the following pigment (CG-1) as a charge generating agent, 10 parts by weight of polyvinyl butyral resin "#6000-C" (manufactured by Denki Kagaku Kogyo Co., Ltd.) as a binder resin, 700 parts by weight of t-butyl acetate as a solvent, and 300 parts by weight of 4-methoxy-4-methyl-2-pentanone were mixed and dispersed using a sand mill for 10 hours to prepare a coating solution [1] for forming a charge generating layer. The obtained charge generating layer forming coating solution [1] was applied onto the intermediate layer [1] by dip coating to form a charge generating layer [1] having a dry thickness (layer thickness) of 0.3 μm.

[0358] [Synthesis of pigment (CG-1)] [1] Synthesis of amorphous titanyl phthalocyanine 29.2 parts by mass of 1,3-diiminoisoindoline was dispersed in 200 parts by mass of o-dichlorobenzene, and 20.4 parts by mass of titanium tetra-n-butoxide was added, followed by heating at 150 to 160° C. for 5 hours in a nitrogen atmosphere. After cooling, the precipitated crystals were filtered, washed with chloroform, washed with a 2% aqueous hydrochloric acid solution, washed with water and methanol, and dried to obtain 26.2 parts by mass (yield 91%) of crude titanyl phthalocyanine. Next, the crude titanyl phthalocyanine was dissolved in 250 parts by mass of concentrated sulfuric acid at 5°C or below by stirring for 1 hour, and the solution was poured into 5,000 parts by mass of water at 20°C. The precipitated crystals were filtered and thoroughly washed with water to obtain 225 parts by mass of a wet paste product. The obtained wet paste product was frozen in a freezer, thawed again, filtered and dried to obtain 24.8 parts by mass of amorphous titanyl phthalocyanine (yield 86%).

[0359] [2] Synthesis of (2R,3R)-2,3-butanediol adduct titanyl phthalocyanine (CG-1) 10.0 parts by mass of the amorphous titanyl phthalocyanine and 0.94 parts by mass (0.6 equivalent ratio) of (2R,3R)-2,3-butanediol (equivalent ratio relative to titanyl phthalocyanine, the same applies hereinafter) were mixed in 200 parts by mass of orthochlorobenzene (ODB) and heated and stirred at 60 to 70°C for 6.0 hours. After leaving it overnight, methanol was added and the resulting crystals were filtered. The filtered crystals were washed with methanol to obtain 10.3 parts by mass of pigment (CG-1) [pigment containing (2R,3R)-2,3-butanediol adduct titanyl phthalocyanine].

[0360] (Formation of charge transport layer) A coating solution for forming a charge transport layer [1] was prepared by mixing and dissolving 225 parts by weight of the following compound A as a charge transport agent, 300 parts by weight of polycarbonate resin "Z300" (manufactured by Mitsubishi Gas Chemical Company, Inc.) as a binder resin, 6 parts by weight of "Irganox 1010" (manufactured by BASF Japan Ltd.) as an antioxidant, 1600 parts by weight of THF (tetrahydrofuran) as a solvent, 400 parts by weight of toluene as a solvent, and 1 part by weight of silicone oil "KF-50" (manufactured by Shin-Etsu Chemical Co., Ltd.). The obtained coating solution for forming a charge transport layer [1] was applied onto the charge generation layer [1] using a circular slide hopper coating device to form a charge transport layer [1] with a dry thickness (layer thickness) of 20 μm.

[0361] [ka]

[0362] (Formation of surface layer) 100 parts by weight of methacrylic monomer "SR350" (manufactured by Sartomer Corporation), 20 parts by weight of charge transport material (compound A), 400 parts by weight of 2-butanol solvent, and 40 parts by weight of THF (tetrahydrofuran) solvent were mixed in the dark, and 10 parts by weight of IRGACURE819 (manufactured by BASF) polymerization initiator was added, and the mixture was stirred in the dark to dissolve, thereby preparing a coating liquid for forming a surface layer. Using a dip coating device, this surface layer forming coating solution was applied onto the charge transport layer to form a coating film, and then irradiated with ultraviolet light using a metal halide lamp for 1 minute to form a surface layer [1] with a dry film thickness of 3.0 μm. The image carrier (1) was produced by the above steps.

[0363] <Preparation of Image Carrier (Photoreceptor) (2)> (Preparation of the conductive support), (Formation of the intermediate layer) and (Formation of the charge transport layer) were the same as those for the image carrier (1).

[0364] (Formation of surface layer) 100 parts by weight of methacrylic monomer "SR350" (manufactured by Sartomer Corporation), 10 parts by weight of Eposter S (melamine particles manufactured by Nippon Shokubai Co., Ltd.) as organic resin particles, 100 parts by weight of NanoTek Powder SnO2 (tin oxide particles manufactured by C.I. Kasei Co., Ltd.) as inorganic particles, 20 parts by weight of charge transport material (compound A), 400 parts by weight of 2-butanol solvent, and 40 parts by weight of THF (tetrahydrofuran) solvent were mixed in the dark and dispersed for 5 hours using a sand mill as a disperser. 10 parts by weight of polymerization initiator IRGACURE819 (manufactured by BASF) was then added and dissolved by stirring in the dark to prepare a coating liquid for forming a surface layer. Using a circular slide hopper type coater, this surface layer forming coating liquid was applied onto the charge transport layer to form a coating film, and then irradiated with ultraviolet light using a metal halide lamp for 1 minute to form a surface layer [2] with a dry film thickness of 3.0 μm. The image carrier (2) was produced by the above steps.

[0365] <Preparation of Image Carriers (Photoreceptors) (3) and (4)> Image carriers (3) and (4) were prepared in the same manner as image carrier (2), except that in (Formation of surface layer), the tin oxide particles were changed to SMT500SAS (titanium oxide particles, manufactured by Teika Corporation) as shown in Table II. The dry film thickness of the image carriers (3) and (4) was 3.0 μm.

[0366] <Preparation of Image Carrier (Photoreceptor) (5)> In (Formation of surface layer), an image carrier (5) was prepared in the same manner as the image carrier (2), except that Sumilizer GS (manufactured by Sumitomo Chemical Co., Ltd.) was added as a hardness adjuster together with the monomers, etc., when preparing the coating liquid for forming the surface layer. The dry film thickness of the image carrier (5) was 3.0 μm.

[0367] <Preparation of Image Carrier (Photoreceptor) (6)> An image carrier (6) was produced in the same manner as the image carrier (2), except that in (formation of surface layer), the ultraviolet irradiation time using a metal halide lamp was changed from 1 minute to 2 minutes. The dry film thickness of the image carrier (6) was 3.0 μm.

[0368] <Preparation of Image Carrier (Photoreceptor) (7)> (Preparation of the conductive support), (Formation of the intermediate layer) and (Formation of the charge transport layer) were the same as those for the image carrier (1).

[0369] (Formation of surface layer) Charge transport material: 180 parts by mass of N-(4-methylphenyl)-N-{4-(β-phenylstyryl)phenyl}-p-toluidine, binder resin: 300 parts by mass of polycarbonate resin "Z300" (manufactured by Mitsubishi Gas Chemical Company, Inc.), inorganic particles: 30 parts by mass of silicon dioxide particles "RX-50" (manufactured by Nippon Aerosil Co., Ltd., primary treatment: dimethyldichlorosilane, secondary treatment: particles with an average primary particle diameter of 50 nm surface-treated with hexamethyldisilazane), antioxidant: 6 parts by mass of "Irganox 1010" (manufactured by BASF Japan Ltd.), solvent: 1,600 parts by mass of tetrahydrofuran, solvent: 400 parts by mass of toluene were mixed and dispersed for 5 hours using a sand mill as a disperser to prepare a coating liquid for forming a surface layer. Using a circular slide hopper type coater, this surface layer forming coating liquid was applied onto the charge transport layer to form a coating film, which was then dried at 120°C for 1 hour to form a surface layer [7] with a dry film thickness of 10 μm. The image carrier (7) was produced by the above steps.

[0370] [Table 2]

[0371] [Examples 1 to 18 and Comparative Examples 1 to 6] (Universal hardness measurement) The universal hardness of the produced image bearing members was calculated by the above-mentioned method using the "Fisherscope HM2000" after the surface layer of each image bearing member was formed.

[0372] (Production of image forming device) The types of the produced cleaning blade and image bearing member were changed as shown in Table III, and the image forming apparatus was assembled with the cleaning blade and the image bearing member.

[0373] A. Evaluation of peeling (Preparation of evaluation equipment) A full-color printing machine (bizhub PRESS C1070, manufactured by Konica Minolta) was modified to a linear speed of 500 mm / sec, the developing unit was removed, and a torque measuring instrument and an oscilloscope were connected to the photosensitive unit and intermediate transfer belt unit, respectively. Furthermore, each cleaning blade prepared by the above process was placed at the cyan (C) position of the photosensitive unit to prepare an image forming apparatus for evaluation. Zinc stearate was used as the lubricant (second lubricant) that is provided as standard in the image forming apparatus.

[0374] (Evaluation method) The evaluation of curling was carried out by driving the photosensitive unit and intermediate transfer belt for 90 minutes in an environment of 30° C. and 85% RH, and measuring the torque value of each while observing whether curling of the cleaning blade occurred. The evaluation criteria are as follows: Evaluation results of "A" to "C" were judged to be acceptable (practical).

[0375] (Evaluation criteria) A: The torque value was 0.60 [N·m] or less (passed). B: Torque value was greater than 0.60 [N·m] and less than 0.80 [N·m] (pass). C: The torque value was greater than 0.80 N m, but the cleaning blade did not retract slightly (passed). D: The torque value was greater than 0.80 [N·m], and slight retraction occurred, but the cleaning blade did not turn over (failed). E: The cleaning blade was turned over (failed).

[0376] B. Evaluation of lubrication maintenance (Preparation of evaluation equipment) An image forming apparatus for evaluation was prepared by modifying a full-color printing machine (bizhub PRESS C1070, manufactured by Konica Minolta) to have a linear speed of 500 mm / sec. Each cleaning blade prepared by the above process was placed at the black (K) position of the photosensitive unit. Zinc stearate was used as the lubricant (second lubricant) that is provided as standard in the image forming apparatus.

[0377] (Evaluation method) The lubricant retention was evaluated by printing a 255-level horizontal band image at 10% coverage on 10,000 sheets of A3-size neutral paper in an environment of 30°C and 85% RH, then removing the photosensitive unit and visually inspecting the presence of lubricant on the photosensitive unit and cleaning blade. The evaluation criteria are as follows: Evaluation results of "A" and "B" were judged to be acceptable (practical).

[0378] (Evaluation criteria) A: Lubricant remained on both the image carrier and the cleaning blade. (Pass) B: Lubricant remained on the cleaning blade, but was scraped off and not left on the image carrier. (Pass) C: No lubricant remained on either the image carrier or the cleaning blade. (Failed)

[0379] C. Evaluation of slip-through (Preparation of evaluation equipment) A full-color printing machine (bizhub PRESS C1070, manufactured by Konica Minolta) was modified to have a linear speed of 500 mm / sec. The image forming apparatus was further modified to use zinc stearate as the lubricant (second lubricant) that is standard equipment in the image forming apparatus, so that the pressing force of the lubricant (second lubricant) against the image carrier was one-third of the initial setting. Each cleaning blade prepared by the above process was placed in the cyan (C) position of the photosensitive unit, and an image forming apparatus for evaluation was prepared using the image forming apparatus.

[0380] (Evaluation method) The toner slip-through evaluation was performed by printing 20,000 sheets of halftone image (a) with a coverage rate of 80%, in which the printed area is on the front side of the paper transport direction and the white area is on the back side, as shown in Figure 6, on A3-size neutral paper in an environment of 10°C and 20% RH, and visually observing the white area on the 20,000th sheet. The evaluation criteria are as follows: Evaluation results of "A" to "C" were judged to be acceptable (practical).

[0381] (Evaluation criteria) A: No stains were found on the white background. (Pass) B: Slight, short streak-like stains occurred on the white background, but this does not pose a problem in practical use. (Pass) C: Slight streak stains occurred on the white background, but this does not pose a problem for practical use. (Pass) D: Obvious streaky stains have appeared on the white background, making it unsuitable for practical use (failed). E: Clear streak stains have appeared in multiple places on the white background, making it unsuitable for practical use (failed).

[0382] D. Evaluation of fogging (Preparation of evaluation equipment) An image forming apparatus for evaluation was prepared by modifying a full-color printing machine (bizhub PRESS C1070, manufactured by Konica Minolta) to have a linear speed of 200 mm / sec. Each cleaning blade prepared by the above process was placed at the black (K) position of the photosensitive unit. Zinc stearate was used as the lubricant (second lubricant) that is provided as standard in the image forming apparatus.

[0383] (Evaluation method) First, in an environment of 23° C. and 50% RH, a vertical band image with 255 gradations and a coverage rate of 10% as shown in FIG. 7 was continuously printed on 1000 sheets of A4 paper in landscape orientation. Next, the transfer material "POD Gloss Coat (A3 size, 100 g / m 2A plain image (solid white image) was formed on a (Oji Paper) under conditions of a grid voltage of -800V and a developing bias of -700V, to prepare a print for evaluating fog. The fog density of the resulting print was measured using a Konica Minolta fluorescent spectrodensitometer "FD-7."

[0384] (a) The absolute image density was measured at 20 arbitrary points on a transfer material (blank paper) on which no image was formed, and the average value was taken as the "blank paper density before image formation."

[0385] (b) The absolute image density was measured at 20 random locations on the print for fog evaluation, and the average value was taken as the "blank paper density after forming a plain image."

[0386] (c) The white paper density obtained in (a) and (b) above was calculated as the fog density based on the following formula: Formula: Fog density = (blank paper density after plain image formation) - (blank paper density before image formation)

[0387] The evaluation criteria are as follows: Evaluation results of "A" to "D" were judged to be acceptable (practical).

[0388] (Evaluation criteria) A: The fog density was 0.003 or less (passed). B: The fog density was more than 0.003 and 0.005 or less (passed). C: The fog density was greater than 0.005 and equal to or less than 0.007 (pass). D: The fog density was greater than 0.007 and equal to or less than 0.01 (pass). E: The fog density is more than 0.01, which is problematic for practical use (failure).

[0389] E. Summary From the results shown in Table III below, the image forming apparatus of the example was found to be superior to the image forming apparatus of the comparative example. Since the evaluations of curling, lubricant maintenance, slip-through and fogging were all excellent overall, it is clear that the image forming apparatus of the present invention has better curling resistance and cleaning properties than the conventional image forming apparatus. In Table III, Examples 1 to 8, 11 and 17 should be read as Reference Examples 1 to 8, 11 and 17, respectively.

[0390] [Table 3] [Explanation of symbols]

[0391] 1Y, 1M, 1C, 1Bk photoconductor 2Y, 2M, 2C, 2Bk Charged part 3Y, 3M, 3C, 3Bk exposure section 4Y, 4M, 4C, 4Bk developing section 5Y, 5M, 5C, 5Bk Primary transfer roller (primary transfer section) 5b Secondary transfer section 6Y, 6M, 6C, 6Bk, 6b Cleaning device 7 Intermediate transfer unit 8. Housing 10Y, 10M, 10C, 10Bk image forming units 20 Paper cassette 21 Paper feed section 22A, 22B, 22C, 22D Intermediate rollers 23 Resist Roller 24 Fixing section 25 Paper ejection roller 26 Paper output tray 70 Intermediate transfer body 71~74 Roller 82R, 82L support rails 100 Image forming device 116Y Lubricant supply section 121 Brush Roller 122 Second Lubricant 122a surface 123 Pressure spring A Main Unit P Paper SC Document Image Reader CL Cleaning Blade E1 Edge 1 E2 Edge 2 SA Face A SB side B SC side C Y image carrier EP end area CP central region 1α photosensitive layer 1a Conductive support 1b Middle layer 1c Charge generation layer 1d charge transport layer 1e surface layer

Claims

1. An image forming apparatus having a mechanism for cleaning the surface of an image carrier with a cleaning blade, the surface layer of the image bearing member contains a binder resin made of at least a polymer of a curable monomer, the cleaning blade has regions at both ends in a longitudinal direction where a first lubricant having fluidity is present, the first lubricant present in the regions at both ends is grease; the first lubricant present in the regions at both ends contains a silicone resin component; the universal hardness of the surface layer is within the range of 200 to 360 N / mm 2 ; a region in the longitudinal center where a second lubricant different from the first lubricant present in the regions at both ends is present; the second lubricant is zinc stearate; an image forming apparatus, characterized in that the regions at both ends where the first lubricant is present are regions that occupy 4 to 8% of the entire length in the longitudinal direction from the ends of the both ends toward the center;

2. the surface layer contains the binder resin, The binder resin contains at least a polymerizable cured product of an acrylic monomer or a methacrylic monomer.

2. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

3. The surface layer contains resin particles having a melamine structure.

3. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

4. The resin particles are particles containing a melamine-formaldehyde resin.

4. The image forming apparatus according to claim 3, wherein the image forming apparatus is a recording medium.

5. The surface layer contains inorganic particles.

5. The image forming apparatus according to claim 1, wherein the image forming apparatus is a recording medium.

6. The inorganic particles contain metal oxide particles.

6. The image forming apparatus according to claim 5,

7. The metal oxide particles are tin oxide particles.

7. The image forming apparatus according to claim 6, wherein the image forming apparatus is a recording medium.

8. An image forming method using a toner for developing an electrostatic latent image, comprising: An image carrier is used in the electrostatic latent image forming process or the toner image transferring process, The image bearing member includes an image bearing member containing a binder resin made of at least a polymer of a curable monomer in a surface layer of the image bearing member, and cleaning the surface of the image bearing member with a cleaning blade having regions in which a first lubricant having fluidity is present at both ends in the longitudinal direction; the first lubricant present in the regions at both ends is grease; the first lubricant present in the regions at both ends contains a silicone resin component; the universal hardness of the surface layer is within the range of 200 to 360 N / mm 2 ; a region in the longitudinal center where a second lubricant different from the first lubricant present in the regions at both ends is present; the second lubricant is zinc stearate; an image forming method, characterized in that the regions of the both end portions where the first lubricant is present are regions of 4 to 8% of the total length in the longitudinal direction from the ends of the both end portions toward the center portion.

9. The cleaning blade has a region in the center in the longitudinal direction where a second lubricant different from the first lubricant present in the regions at both ends is present.

9. The image forming method according to claim 8.

Images