JP2015219265A - Image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming apparatus that achieves a long service life and can inhibit image irregularity or image deletion in a high-temperature and high-humidity environment while maintaining good toner cleaning property.SOLUTION: The image forming apparatus includes: a photoreceptor having a protective layer comprising a cured resin; charging means employing a proximity charging system to charge a surface of the photoreceptor; exposing means for exposing the photoreceptor; developing means for supplying a toner to the photoreceptor to from a toner image; transfer means for transferring the toner image; lubricant supply means for supplying a lubricant to the surface of the photoreceptor; cleaning means for removing the toner remaining on the surface of the photoreceptor; and lubricant removing means for removing the lubricant from the surface of the photoreceptor. The lubricant removing means comprises a brush having a brush fiber material to be in contact with the photoreceptor, in which at least a surface of the brush fiber material to be in contact with the photoreceptor is coated with a layer of metal oxide fine particles.

Description

  The present invention relates to an electrophotographic image forming apparatus.

  2. Description of the Related Art Conventionally, an electrophotographic image forming apparatus is required to have a long life and image quality stability. The life of a photoreceptor, which is an important functional member in an image forming apparatus, is determined by the degree of wear of the photosensitive layer. Further, the occurrence of minute scratches or uneven wear causes image quality deterioration, and the image forming unit including the photosensitive member needs to be replaced.

  In recent years, a protective layer made of a cross-linked curable resin is laminated on the surface of a photoreceptor to improve wear resistance, scratch resistance, and environmental stability, and to extend the life.

  In recent years, as a charging method for photoconductors, it is advantageous for high image quality and apparatus miniaturization, and proximity charging that can reduce the generation amount of oxidizing gases such as ozone and NOx compared to scorotron and corotron charging methods. The method is adopted. Here, the proximity charging method refers to a charging method in which a charging member made of a charging roller or the like is charged by contacting or approaching the surface of the photoreceptor.

  However, when a proximity charging method is applied to a photoconductor having a protective layer made of a cross-linked curable resin, the degree of deterioration of the surface of the photoconductor is greater than the rate of surface polishing, and an attached discharge is generated. There is a problem that the torque increases due to the object and causes cleaning failure and toner filming associated with the cleaning blade chipping and chipping.

  In order to solve this problem of poor cleaning and toner filming, a lubricant (lubricant) is applied to the surface of the photoconductor to form a lubricant film on the surface of the photoconductor, thereby reducing the adhesion force of the toner. It has been known. Thereby, the torque of the cleaning blade can be reduced, and the cleaning performance is improved.

  However, in the proximity charging method, there is a problem that when the charging process is repeatedly performed, the lubricant is deteriorated and transformed into a water-absorbing substance, thereby promoting image flow in a high temperature and high humidity environment.

As a means for solving such a problem, it has been proposed to provide a lubricant removing means for removing a deteriorated lubricant while securing a necessary and sufficient amount of lubricant during cleaning.
For example, Patent Document 1 discloses that a lubricant removing unit including a brush member that rubs the surface of the photoreceptor is provided. Further, for example, Patent Document 2 discloses providing a lubricant removing means made of, for example, a non-contact type electrostatic cleaning member for removing powdery lubricant.

  However, since the lubricant removing means disclosed in Patent Document 1 and Patent Document 2 is inferior to the point of removing the lubricant film on the surface of the photoreceptor uniformly, the image flow cannot be sufficiently suppressed, and In the next image forming process, the lubricant film on the surface of the photoconductor is subject to a large variation in the amount of lubricant present, and this variation in the amount of lubricant presents as a difference in density, thus forming There is a problem that image unevenness occurs in the image to be generated.

  Further, for example, Patent Document 3 and Patent Document 4 disclose a lubricant removing means including a scraping roller that scrapes off foreign matter adhering to the surface of the photoreceptor.

  However, when such a lubricant removing means is used, a scraping force larger than the adhesion force between the foreign matter and the photosensitive member is required when the foreign matter attached to the surface of the photosensitive member is scraped off. As a result, a force is similarly applied to a portion of the photoconductor where no foreign matter is adhered. As a result, a large stress is applied to the surface of the photoconductor and the surface of the photoconductor is scraped off. There is a problem that the life of the body cannot be extended.

Japanese Patent Application Laid-Open No. 2005-309311 JP 2008-122869 A JP 2005-164726 A JP 2002-278403 A

  The present invention has been made in consideration of the circumstances as described above, and the object thereof is to extend the life of the toner and to have a good toner cleaning property in an uneven image or high temperature and high humidity environment. An object of the present invention is to provide an image forming apparatus capable of suppressing the occurrence of image flow.

An image forming apparatus according to the present invention includes a photosensitive member having a protective layer made of a cured resin, a charging unit using a proximity charging method for charging the surface of the photosensitive member, and an exposing unit for exposing the photosensitive member charged by the charging unit. A developing unit that supplies toner to the photoconductor exposed by the exposure unit to form a toner image, a transfer unit that transfers the toner image formed on the photoconductor, and a lubricant on the surface of the photoconductor. An image forming apparatus comprising: a lubricant supply means for supplying; a cleaning means for removing toner remaining on the surface of the photoreceptor; and a lubricant removal means for removing the lubricant from the surface of the photoreceptor,
The lubricant removing means comprises a brush having a brush fiber body in contact with the photoconductor, and at least the surface of the brush fiber body in contact with the photoconductor is covered with a layer of metal oxide fine particles. .

  In the image forming apparatus of the present invention, it is preferable that the surface of the metal oxide fine particles is hydrophobized with a silane coupling agent.

  In the image forming apparatus of the present invention, it is preferable that the protective layer of the photoreceptor contains metal oxide fine particles that have been surface-treated with a surface treatment agent comprising a compound having a reactive organic group.

  In the image forming apparatus of the present invention, the protective layer of the photoreceptor preferably contains organic fine particles made of a compound having a melamine structure.

  In the image forming apparatus of the present invention, it is preferable that the metal oxide fine particles comprise at least one selected from the group of silica particles, alumina particles, and titanium oxide particles.

The image forming apparatus of the present invention, the protective layer of the photosensitive member is preferably universal hardness is of 280N / mm ² or more 600N / mm ² or less.

  According to the image forming apparatus of the present invention, since the lubricant removing means comprising the brush having the brush fiber body whose surface is covered with the layer made of the metal oxide is provided, the life can be extended and the good It is possible to suppress the occurrence of image unevenness and image flow in a high temperature and high humidity environment while having excellent toner cleaning properties.

1 is a cross-sectional view illustrating an example of a configuration of an image forming apparatus according to the present invention. FIG. 2 is an explanatory cross-sectional view illustrating an example of a configuration of a main part of the image forming apparatus of the present invention.

  Hereinafter, the present invention will be described in detail.

[Image forming apparatus]
FIG. 1 is an explanatory sectional view showing an example of the configuration of the image forming apparatus of the present invention.
This image forming apparatus 100 is called a tandem type color image forming apparatus, and includes four sets of image forming units 110Y, 110M, 110C, and 110Bk, an intermediate transfer body unit 130, a paper feeding / conveying means 150, and a fixing means. 170. A document image reading device SC is arranged on the upper part of the main body of the image forming apparatus 100.

  The image forming units 110Y, 110M, 110C, and 110Bk are arranged side by side in the vertical direction. The image forming units 110Y, 110M, 110C, and 110Bk include drum-shaped photoreceptors 111Y, 111M, 111C, and 111Bk that are rotated, and a lubricant supply unit 116Y that is sequentially arranged in the outer surface area along the rotational direction of the photoreceptor. 116M, 116C, 116Bk, proximity charging type charging means 113Y, 113M, 113C, 113Bk, exposure means 115Y, 115M, 115C, 115Bk, developing means 117Y, 117M, 117C, 117Bk, lubricant removal means 114Y, 114M, 114C, 114Bk and cleaning means 119Y, 119M, 119C, 119Bk. Then, toner images of yellow (Y), magenta (M), cyan (C), and black (Bk) are formed on the photoreceptors 111Y, 111M, 111C, and 111Bk, respectively. Since the image forming units 110Y, 110M, 110C, and 110Bk are configured similarly except that the colors of the toner images formed on the photoconductors 111Y, 111M, 111C, and 111Bk are different, the following description will be made with an example of the image forming unit 110Y. .

[Photoconductor]
The photoreceptor 111Y has a drum shape having a protective layer containing a cross-linked polymer obtained by curing a composition containing a polymerizable compound by a polymerization reaction as a surface layer. Specifically, the photoreceptor 111Y of this example has an intermediate layer on a conductive support, and a charge generation layer containing a charge generation material and a charge transport material containing a charge transport material on the intermediate layer. A photosensitive layer is formed by laminating layers in this order, and a protective layer is formed as a surface layer on the photosensitive layer (charge transport layer). The photosensitive layer may have a single-layer structure including a charge generation material and a charge transport material.

(Protective layer)
The protective layer of the photoreceptor 111Y is made of a cured resin made of a crosslinked polymer obtained by curing a composition containing a polymerizable compound by a polymerization reaction, and the surface made of a compound having a reactive organic group in the cured resin. It is preferable that metal oxide fine particles surface-treated with a treating agent are contained.

(Polymerizable compound)
The cured resin constituting the protective layer is obtained by polymerizing a polymerizable compound having two or more polymerizable functional groups by irradiation with actinic rays such as ultraviolet rays and electron beams, and curing by forming a crosslinked bond by a crosslinking reaction. It consists of the obtained crosslinked polymer.
As the polymerizable compound, those having two or more polymerizable functional groups can be used, and those having one polymerizable functional group can be used in combination. Specifically, examples of the polymerizable compound include styrene monomers, acrylic monomers, methacrylic monomers, vinyl toluene monomers, vinyl acetate monomers, N-vinyl pyrrolidone monomers, and the like.

As the polymerizable compound, an acrylic monomer having two or more acryloyl groups (CH ₂ ═CHCO—) or methacryloyl groups (CH ₂ ═CCH ₃ CO—) can be cured with a small amount of light or in a short time. Or it is especially preferable that they are these oligomers.

  In this invention, a polymeric compound may be used individually by 1 type, or may mix and use 2 or more types. In addition, these polymerizable compounds may use monomers, but may be used after oligomerization.

  Specific examples of the polymerizable compound are shown below.

However, in the chemical formulas showing the exemplified compounds M1 to M14, R represents an acryloyl group (CH ₂ ═CHCO—), and R ′ represents a methacryloyl group (CH ₂ ═CCH ₃ CO—).

(Metal oxide fine particles)
The protective layer contains fine metal oxide particles surface-treated with a surface treatment agent (hereinafter, also referred to as “reactive organic group-containing surface treatment agent”) made of a compound having a reactive organic group. The metal oxide fine particles are obtained by subjecting metal oxide fine particles (hereinafter also referred to as “untreated metal oxide fine particles”) as a raw material to a surface treatment with a reactive organic group-containing surface treatment agent. A reactive organic group is introduced on the surface of the fine particles.

  Examples of the untreated metal oxide fine particles include silica (silicon oxide), magnesium oxide, zinc oxide, lead oxide, alumina (aluminum oxide), zirconium oxide, tin oxide, titania (titanium oxide), niobium oxide, molybdenum oxide, Vanadium oxide or the like can be used, and among these, tin oxide is preferable from the viewpoints of hardness, conductivity, and light transmittance.

  The number average primary particle size of the metal oxide fine particles is preferably 1 to 300 nm, more preferably 3 to 100 nm, and still more preferably 5 to 40 nm.

  In the present invention, the number average primary particle size of the metal oxide fine particles is a photographic image obtained by taking a magnified photograph of 10,000 times with a scanning electron microscope (manufactured by JEOL Ltd.) and randomly capturing 300 particles with a scanner (aggregation). The number average primary particle size was calculated using an automatic image processing analyzer “LUZEX AP (software version Ver. 1.32)” (manufactured by Nireco Corporation).

The reactive organic group-containing surface treatment agent is preferably one that reacts with a hydroxy group or the like present on the surface of the untreated metal oxide fine particles. As such a reactive organic group-containing surface treatment agent, for example, a silane cup Examples thereof include a ring agent and a titanium coupling agent.
Moreover, as a reactive organic group containing surface treating agent, the surface treating agent which has a radically polymerizable reactive group is preferable. Examples of the radical polymerizable reactive group include a vinyl group, an acryloyl group, and a methacryloyl group. Such a radical polymerizable reactive group can react with the polymerizable compound according to the present invention to form a strong protective layer. As the surface treatment agent having a radical polymerizable reactive group, a silane coupling agent having a radical polymerizable reactive group such as a vinyl group, an acryloyl group, or a methacryloyl group is preferable.

  Hereinafter, specific examples of the reactive organic group-containing surface treatment agent will be shown.

_{S-1: CH 2 = CHSi} (CH 3) (OCH 3) 2
_{S-2: CH 2 = CHSi} (OCH 3) 3
S-3: CH ₂ = CHSiCl _{3
S-4: CH 2 = CHCOO} (CH 2) 2 Si (CH 3) (OCH 3) 2
_{S-5: CH 2 = CHCOO} (CH 2) 2 Si (OCH 3) 3
_{S-6: CH 2 = CHCOO} (CH 2) 2 Si (OC 2 H 5) (OCH 3) 2
_{S-7: CH 2 = CHCOO} (CH 2) 3 Si (OCH 3) 3
_{S-8: CH 2 = CHCOO} (CH 2) 2 Si (CH 3) Cl 2
_{S-9: CH 2 = CHCOO} (CH 2) 2 SiCl 3
_{S-10: CH 2 = CHCOO} (CH 2) 3 Si (CH 3) Cl 2
S-11: CH ₂ = CHCOO (CH ₂ ) ₃ SiCl _{3
S-12: CH 2 = C} (CH 3) COO (CH 2) 2 Si (CH 3) (OCH 3) 2
_{S-13: CH 2 = C} (CH 3) COO (CH 2) 2 Si (OCH 3) 3
_{S-14: CH 2 = C} (CH 3) COO (CH 2) 3 Si (CH 3) (OCH 3) 2
_{S-15: CH 2 = C} (CH 3) COO (CH 2) 3 Si (OCH 3) 3
_{S-16: CH 2 = C} (CH 3) COO (CH 2) 2 Si (CH 3) Cl 2
_{S-17: CH 2 = C} (CH 3) COO (CH 2) 2 SiCl 3
_{S-18: CH 2 = C} (CH 3) COO (CH 2) 3 Si (CH 3) Cl 2
_{S-19: CH 2 = C} (CH 3) COO (CH 2) 3 SiCl 3
_{S-20: CH 2 = CHSi} (C 2 H 5) (OCH 3) 2
_{S-21: CH 2 = C} (CH 3) Si (OCH 3) 3
_{S-22: CH 2 = C} (CH 3) Si (OC 2 H 5) 3
_{S-23: CH 2 = CHSi} (OCH 3) 3
_{S-24: CH 2 = C} (CH 3) Si (CH 3) (OCH 3) 2
_{S-25: CH 2 = CHSi} (CH 3) Cl 2
_{S-26: CH 2 = CHCOOSi} (OCH 3) 3
_{S-27: CH 2 = CHCOOSi} (OC 2 H 5) 3
_{S-28: CH 2 = C} (CH 3) COOSi (OCH 3) 3
_{S-29: CH 2 = C} (CH 3) COOSi (OC 2 H 5) 3
_{S-30: CH 2 = C} (CH 3) COO (CH 2) 3 Si (OC 2 H 5) 3
_{S-31: CH 2 = CHCOO} (CH 2) 2 Si (CH 3) 2 (OCH 3)
_{S-32: CH 2 = CHCOO} (CH 2) 2 Si (CH 3) (OCOCH 3) 2
_{S-33: CH 2 = CHCOO} (CH 2) 2 Si (CH 3) (ONHCH 3) 2
_{S-34: CH 2 = CHCOO} (CH 2) 2 Si (CH 3) (OC 6 H 5) 2
_{S-35: CH 2 = CHCOO} (CH 2) 2 Si (C 10 H 21) (OCH 3) 2
_{S-36: CH 2 = CHCOO} (CH 2) 2 Si (CH 2 C 6 H 5) (OCH 3) 2

  As the reactive organic group-containing surface treatment agent, a silane compound having a radical polymerizable reactive organic group can be used in addition to those shown in the above S-1 to S-36.

  The reactive organic group-containing surface treatment agent may be used alone or in combination of two or more.

  It is preferable that the usage-amount of a reactive organic group containing surface treating agent is 0.1-200 mass parts with respect to 100 mass parts of untreated metal oxide fine particles, More preferably, it is 7-70 mass parts.

  Examples of the treatment method for the untreated metal oxide fine particles of the reactive organic group-containing surface treatment agent include, for example, a slurry containing untreated metal oxide fine particles and a reactive organic group-containing surface treatment agent (suspension of solid particles). The method of wet crushing is mentioned. By this method, re-aggregation of the untreated metal oxide fine particles is prevented, and at the same time, the surface treatment of the untreated metal oxide fine particles proceeds. Thereafter, the solvent is removed to form powder.

  Examples of the surface treatment apparatus include a wet media dispersion type apparatus. In this wet media dispersion type device, beads are filled as a medium in a container, and agitation disk mounted perpendicular to the rotation axis is rotated at high speed to crush and pulverize agglomerated particles of untreated metal oxide fine particles. It is an apparatus having a step of dispersing, and the structure thereof is not limited as long as the untreated metal oxide fine particles are sufficiently dispersed and surface treated when performing surface treatment on the untreated metal oxide fine particles. For example, various types such as a vertical type, a horizontal type, a continuous type, and a batch type can be adopted. Specifically, a sand mill, ultra visco mill, pearl mill, glen mill, dyno mill, agitator mill, dynamic mill and the like can be used. These dispersion-type devices are finely pulverized and dispersed by impact crushing, friction, shearing, shear stress, etc., using a grinding medium (media) such as balls and beads.

  As beads used in the wet media dispersion type apparatus, balls made of glass, alumina, zircon, zirconia, steel, flint stone, etc. can be used, but those made of zirconia or zircon are particularly preferable. Further, as the size of the beads, those having a diameter of about 1 to 2 mm are usually used, but in the present invention, those having a diameter of about 0.1 to 1.0 mm are preferably used.

  Various materials such as stainless steel, nylon and ceramic can be used for the disk and container inner wall used in the wet media dispersion type apparatus. In the present invention, the disk and container inner wall made of ceramic such as zirconia or silicon carbide are particularly used. Is preferred.

  The content of the metal oxide fine particles in the protective layer is preferably 20 to 170 parts by mass, more preferably 25 to 130 parts by mass with respect to 100 parts by mass of the cured resin. The crosslinked polymer constituting the cured resin in the protective layer may be considered to be constituted by a curing reaction of all the polymerizable compounds contained in the protective layer-forming coating liquid described later.

(Organic fine particles)
The protective layer may contain organic fine particles made of a compound having a melamine structure. The organic fine particles may be, for example, composite particles composed of a compound having a melamine structure and a metal oxide.
Specific examples of the compound having a melamine structure include melamine resins such as a polycondensate of melamine and formaldehyde and a copolycondensate of melamine, benzoguanamine and formaldehyde.
Since the organic fine particles made of a compound having a melamine structure are contained in the protective layer, the organic fine particles are a low-friction material, so that lubricity is imparted to the surface of the photoreceptor and good cleaning properties can be obtained. . In addition, since the compound having a melamine structure is highly compatible with the cured resin, the organic fine particles are highly dispersible in the cured resin, and further, the organic fine particles are less detached from the protective layer. Is maintained in a state where it exists on the surface of the photoreceptor, a good cleaning property can be obtained over a long period of time.

The number average primary particle size of the organic fine particles is preferably from 100 nm to 1500 nm, and more preferably from 200 nm to 1000 nm.
When the number average primary particle size of the organic fine particles is within the above range, good cleaning properties can be obtained while ensuring the light transmittance of the protective layer.
In the case where the number average primary particle size of the organic fine particles is too small, the organic fine particles are likely to aggregate with each other, and good cleaning properties may not be obtained. On the other hand, in the case where the number average primary particle size of the organic fine particles is excessive, the light transmittance becomes low and the material tends to settle, so that the light transmittance of the protective layer cannot be ensured, There is a possibility that good cleaning properties may not be obtained.

In the present invention, the number average primary particle size of the organic fine particles is a value measured as follows.
First, as a measurement sample, a photosensitive layer including a protective layer is cut out from the surface of the photoreceptor with a knife or the like, and attached to an arbitrary holder so that the cut surface faces upward.
And a measurement sample is computed from the photograph image observed and image | photographed with the transmission electron microscope. A photograph is taken with the magnification of the microscope set to 10,000 times, and 100 particles are randomly extracted from the photograph image and calculated. Specifically, the horizontal ferret diameter of 100 fine particles is measured by image analysis processing, an average value is calculated, and this is used as the number average primary particle diameter. Note that the image analysis processing can be automatically performed by, for example, driving a program built in the transmission electron microscope measurement apparatus. In the present invention, a transmission electron microscope “JEM-2000FX” (manufactured by JEOL Ltd.) was used to measure the particle size of the fine particles.

  The refractive index of the organic fine particles is preferably 1.4 to 1.8, for example, from the viewpoint of ensuring the light transmittance of the protective layer. For example, the refractive index of melamine resin is about 1.6 as a general literature value.

The organic fine particles are preferably contained in a proportion of 5 to 75 parts by mass with respect to 100 parts by mass of the cured resin, and more preferably 10 to 50 parts by mass.
When the content ratio of the organic fine particles is within the above range, light transmittance and cleaning properties can be ensured.

  The protective layer may contain other components in addition to the cured resin, metal oxide fine particles, and organic fine particles. For example, various antioxidants can be contained, and various lubricant particles are added. You can also. For example, fluorine atom-containing resin particles can be added. Examples of the fluorine atom-containing resin particles include tetrafluoroethylene resin, trifluorinated ethylene chloride resin, hexafluoroethylene chloride propylene resin, vinyl fluoride resin, vinylidene fluoride resin, ethylene difluoride dichloride resin, and these One or two or more types are preferably selected from the copolymers, but tetrafluoroethylene resin and vinylidene fluoride resin are particularly preferable.

  The protective layer is prepared by adding a polymerizable compound, metal oxide fine particles, organic fine particles, a polymerization initiator and, if necessary, other components to a known solvent to prepare a coating solution. Layer) is applied to the outer peripheral surface to form a coating film, this coating film is dried, and irradiated with active rays such as ultraviolet rays and electron beams to polymerize and cure the polymerizable compound components in the coating film. Can be formed.

  The protective layer as described above is formed as a cross-linked curable resin by a reaction between polymerizable compounds and the like.

  As the solvent used for forming the protective layer, any solvent can be used as long as the polymerizable compound and the metal oxide fine particles can be dissolved or dispersed. For example, 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-dioxane, 1,3-dioxolane, pyridine and Although diethylamine etc. are mentioned, it is not limited to these.

  As a coating method of the coating liquid for forming the protective layer, for example, dip coating method, spray coating method, spinner coating method, bead coating method, blade coating method, beam coating method, slide hopper method, circular slide hopper method, etc. are known. The method is mentioned.

  The coating film may be cured without being dried, but it is preferable to perform the curing treatment after natural drying or heat drying.

  Drying conditions can be appropriately selected depending on the type of solvent, film thickness, and the like. The drying temperature is preferably room temperature to 180 ° C, particularly preferably 80 to 140 ° C. The drying time is preferably 1 minute to 200 minutes, and particularly preferably 5 minutes to 100 minutes.

Examples of the method of reacting the polymerizable compound include a method of reacting by electron beam cleavage, a method of adding a radical polymerization initiator and reacting with light and heat. As the radical polymerization initiator, either a photopolymerization initiator or a thermal polymerization initiator can be used. A photopolymerization initiator and a thermal polymerization initiator can also be used in combination.
As a method of reacting the polymerizable compound, it is preferable to employ a method of reacting with light because the universal hardness of the protective layer can be controlled by changing the light irradiation time, the light wavelength, or the like.

Examples of the thermal polymerization initiator include 2,2′-azobisisobutyronitrile, 2,2′-azobis (2,4-dimethylazobisvaleronyl), 2,2′-azobis (2-methyl). Azo compounds such as butyronitrile); benzoyl peroxide (BPO), di-tert-butyl hydroperoxide, tert-butyl hydroperoxide, chlorobenzoyl peroxide, dichlorobenzoyl peroxide, bromomethylbenzoyl peroxide, lauroyl peroxide, etc. And peroxides.
Examples of the photopolymerization initiator include diethoxyacetophenone, 2,2-dimethoxy-1,2-diphenylethane-1-one, 1-hydroxy-cyclohexyl-phenyl-ketone, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ketone, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1 (“Irgacure 369” manufactured by BASF Japan Ltd.), 2-hydroxy-2 -Methyl-1-phenylpropan-1-one, 2-methyl-2-morpholino (4-methylthiophenyl) propan-1-one, 1-phenyl-1,2-propanedione-2- (o-ethoxycarbonyl) Acetophenone or ketal photoinitiators such as oximes; benzoin, benzoin methyl ether Benzoin ether photopolymerization initiators such as benzoin ethyl ether, benzoin isobutyl ether, benzoin isopropyl ether; benzophenone, 4-hydroxybenzophenone, methyl o-benzoylbenzoate, 2-benzoylnaphthalene, 4-benzoylbiphenyl, 4-benzoyl Benzophenone photopolymerization initiators such as phenyl ether, acrylated benzophenone, 1,4-benzoylbenzene; 2-isopropylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2,4- Examples thereof include thioxanthone photopolymerization initiators such as dichlorothioxanthone.
Examples of other photopolymerization initiators include ethyl anthraquinone, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, 2,4,6-trimethylbenzoylphenylethoxyphosphine oxide, and bis (2,4,6-trimethylbenzoyl). Phenylphosphine oxide, bis (2,4-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, methylphenylglyoxyester, 9,10-phenanthrene, acridine compounds, triazine compounds, imidazole compounds, etc. Can be mentioned. In addition, a photopolymerization accelerator having a photopolymerization promoting effect can be used alone or in combination with the photopolymerization initiator. Examples of the photopolymerization accelerator include triethanolamine, methyldiethanolamine, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, (2-dimethylamino) ethyl benzoate, and 4,4′-dimethylaminobenzophenone. Etc.

  As the radical polymerization initiator, a photopolymerization initiator is preferable, and an alkylphenone compound or a phosphine oxide compound is particularly preferable. In particular, a compound having an α-aminoalkylphenone structure or an acylphosphine oxide structure is preferable.

  One polymerization initiator may be used alone, or two or more polymerization initiators may be mixed and used.

  It is preferable that the addition ratio of a polymerization initiator is 0.1-20 mass parts with respect to 100 mass parts of polymeric compounds, More preferably, it is 0.5-10 mass parts.

  A cross-linked polymer is produced by irradiating a coating film containing a polymerizable compound with active rays, generating radicals, polymerizing, and forming a cross-linking bond by a cross-linking reaction between molecules and within a molecule and curing. . As the actinic radiation, ultraviolet rays and electron beams are more preferred, and ultraviolet rays are particularly preferred because they are easy to use.

As the ultraviolet light source, any light source that generates ultraviolet light can be used without limitation. For example, a low pressure mercury lamp, a medium pressure mercury lamp, a high pressure mercury lamp, an ultrahigh pressure mercury lamp, a carbon arc lamp, a metal halide lamp, a xenon lamp, a flash (pulse) xenon, or the like can be used.
Irradiation conditions vary depending on each lamp, but the irradiation amount of active rays is usually 5 to 500 mJ / cm ² , preferably 5 to 100 mJ / cm ² .
The power of the lamp is preferably 0.1 kW to 5 kW, particularly preferably 0.5 kW to 3 kW.

  As an electron beam source, there is no particular limitation on the electron beam irradiation apparatus, and generally, an electron beam accelerator for electron beam irradiation is a curtain beam type that is relatively inexpensive and can provide a large output. Used. The acceleration voltage during electron beam irradiation is preferably 100 to 300 kV. The absorbed dose is preferably 0.5 to 10 Mrad.

  The irradiation time for obtaining the necessary amount of active ray irradiation is preferably 0.1 second to 10 minutes, and more preferably 0.1 second to 5 minutes from the viewpoint of work efficiency.

  In the step of forming the protective layer, drying can be performed before and after irradiation with active rays and during irradiation with active rays, and the timing of drying can be appropriately selected by combining these.

Universal hardness of the protective layer is preferably 280N / mm ² or more 600N / mm ² or less, more preferably 500 N / mm ² or more 600N / mm ² or less.
When the universal hardness of the protective layer is within the above range, the surface of the photoconductor has high wear resistance. Therefore, the degraded lubricant film can be obtained by increasing the rubbing force of the lubricant removing means described later. As a result, it is possible to reliably remove the image flow caused by the presence of the deteriorated lubricant film.

In the present invention, the universal hardness of the protective layer is a value measured by an ultra micro hardness test system “Fischer Scope H100” (manufactured by Fischer Instruments).
Specifically, from the indentation depth h and the load F when the surface of the photoreceptor is pushed by applying the load F to the diamond square pyramid Vickers indenter under the test load by the “Fischer scope H100”, the following formula (1) is given. Ask.
Formula (1): HU (universal hardness) = F / (26.45 × h ² )

  The universal hardness of the protective layer can be controlled by the curing treatment conditions (active ray irradiation time and active ray type) when forming the protective layer and the type of polymerizable compound.

  The thickness of the protective layer is preferably 0.2 to 10 μm, more preferably 0.5 to 6 μm.

  In the photoreceptor of the present invention, various known layers can be employed other than the protective layer.

(Charging means)
The charging unit 113Y is a unit that charges the surface of the photoreceptor 111Y by a proximity charging method.
Here, the proximity charging method refers to a charging method using proximity discharge generated in a minute gap near the surface of the photoreceptor. Specifically, the proximity charging method includes a contact roller charging method, a non-contact roller charging method, a brush charging method, and the like.
The charging unit 113Y in this example includes a charging roller disposed in contact with the surface of the photoreceptor 111Y, and a power source that applies a voltage to the charging roller.
The charging roller is formed by, for example, forming a resistance adjustment layer on a conductive support.

[Exposure means]
The exposure unit 115Y exposes the surface of the photoreceptor 111Y to which the uniform potential is applied by the charging unit 113Y based on an image signal (yellow image signal), and forms an electrostatic latent image corresponding to the yellow image. It is means to do. As the exposure means 115Y, a device composed of an LED in which light emitting elements are arranged in an array in the axial direction of the photoconductor 111Y and an imaging element, or a laser optical system is used.

[Development means]
The developing unit 117Y is a unit that supplies toner to the surface of the photoreceptor 111Y, develops the electrostatic latent image formed on the surface of the photoreceptor 111Y, and forms a toner image. Specifically, the developing means 117Y of this example has a built-in magnet, a developing sleeve that holds the developer and rotates, and a voltage application that applies a DC and / or AC bias voltage between the developing sleeve and the photosensitive member. Consists of devices.

[Lubricant supply means]
The lubricant supply means 116Y is a means for supplying a lubricant to the surface of the photoreceptor 111Y, and a lubricant film is formed on the surface of the photoreceptor 111Y by the lubricant supply means 116Y.
In this image forming apparatus, the lubricant supply unit 116Y is disposed on the downstream side of the cleaning unit 119Y and the upstream side of the charging unit 113Y in the rotation direction of the photoreceptor 111Y.
The installation position of the lubricant supply unit 116Y is not limited to the downstream side of the cleaning unit 119Y and the upstream side of the charging unit 113Y. For example, the installation position of the lubricant supply unit 116Y is downstream of the lubricant removal unit 114Y and upstream of the cleaning unit 119Y. You can also

  The lubricant supply means 116Y in this example is constituted by a solid lubricant and an application member made of a brush roller. Specifically, the lubricant supply means 116Y photosensitively contacts the lubricant stock composed of a solid lubricant having a rectangular parallelepiped shape, and the lubricant scraped by rubbing the lubricant stock surface in contact with the surface of the photoreceptor 111Y. A brush roller that is applied to the surface of the body 111Y, a pressure spring that presses the lubricant stock against the brush roller, and a drive mechanism (not shown) that drives the brush roller to rotate. In the brush roller, the tip of the brush is in contact with the surface of the photoreceptor 111Y. The brush roller is driven to rotate at the same speed as the rotation direction of the photoconductor 111Y.

As a brush roller, for example, a pile woven fabric obtained by weaving a bundle of fibers as a pile yarn on a base fabric is made into a ribbon-like fabric, and the brushed surface is wound outward and spirally wound around a metal shaft and bonded. Can be used. The brush roller of this example is formed by forming a long woven fabric formed of resin brush fibers such as polypropylene at a high density on the peripheral surface of a roller base.
The brush bristles are preferably raised straight in the direction perpendicular to the metal shaft from the viewpoint of coating ability. The yarn used for the brush hair is preferably a filament yarn, and examples of the material include synthetic resins such as 6-nylon, 12-nylon, polyester, acrylic, and vinylon, and metals such as carbon and nickel are used for the purpose of increasing conductivity. It may be kneaded. The thickness of the brush fiber is, for example, 3 to 7 denier, the bristle length of the brush fiber is 2 to 5 mm, the electrical resistivity of the brush fiber is 1 × 10 ¹⁰ Ω or less, the Young's modulus of the brush fiber is 4900 to 9800 N / mm ² , the brush The fiber planting density (number of brush fibers per unit area) is preferably, for example, 50,000 to 200,000 fibers / in ² (50 k to 200 k fibers / inch ² ). The biting amount of the brush roller with respect to the photosensitive member is preferably 0.5 to 1.5 mm. The rotation speed of the brush roller is, for example, 0.3 to 1.5 in terms of the peripheral speed ratio of the photoconductor, and the rotation may be in the same direction as the rotation direction of the photoconductor or in the opposite direction.

  The pressure spring is used to press the lubricant stock in a direction close to the photoreceptor 111Y so that the pressing force of the brush roller against the photoreceptor 111Y is, for example, 0.5 to 1.0N.

In the lubricant supply means 116Y, for example, for the brush roller of the lubricant stock so that the coating amount per 1 cm ² of the surface of the photoreceptor 111Y is 0.5 × 10 ^{−7 to} 1.5 × 10 ⁻⁷ g / cm ² . The pressing force and the rotation speed of the brush roller are adjusted.

  As the lubricant, for example, fatty acid metal salts such as zinc oleate, zinc stearate, calcium stearate and the like can be used. Among these, zinc stearate is preferably used from the viewpoints of lubricity and spreadability.

  In the image forming apparatus of this example, the lubricant is supplied by the method of applying the solid lubricant by the lubricant supplying means including the brush roller. However, as the lubricant supplying method, The method is not limited, and a method in which a fine powder lubricant externally added to the toner is supplied to the photoreceptor by the action of a developing electric field formed in the developing step may be employed. At this time, the number average primary particle size of the lubricant is preferably, for example, 0.5 to 20 μm. Further, the lubricant is preferably added at a ratio of 0.01 to 0.3% by mass with respect to the toner so as not to affect the chargeability of the toner. The fine powder lubricant externally added to the toner is not particularly limited as long as it has lubricity and cleavage, but for example, zinc stearate can be used.

[Cleaning means]
The cleaning unit 119Y is a unit that removes toner remaining on the surface of the photoreceptor 111Y. The cleaning means 119Y in this example is constituted by a cleaning blade. As shown in FIG. 2, the cleaning blade includes a support member 31 and a blade member 30 supported on the support member 31 via an adhesive layer (not shown). The blade member 30 is disposed in a state where the tip thereof faces in the direction (counter direction) opposite to the rotation direction of the photoconductor 111Y at the contact portion with the surface of the photoconductor 111Y.

  The support member 31 is not particularly limited, and a conventionally known member can be used, and examples thereof include those manufactured from rigid metal, elastic metal, plastic, ceramic, and the like. Among these, a rigid metal is preferable.

  As the blade member 30, for example, a multi-layer structure in which a base layer and an edge layer are laminated can be used. Each of the base layer and the edge layer is preferably made of polyurethane. Examples of the polyurethane include those obtained by reacting a polyol, a polyisocyanate, and, if necessary, a crosslinking agent.

[Lubricant removing means]
The lubricant removing unit 114Y is a unit that removes the lubricant adhering to the surface of the photoreceptor 111Y. The lubricant removing unit 114Y is disposed on the upstream side of the cleaning unit 119Y and the downstream side of the transfer unit 113Y in the rotation direction of the photoreceptor 111Y.
The lubricant removing unit 114Y includes a brush having a brush fiber body that contacts the photoreceptor 111Y and a drive mechanism. The brush is preferably a roller-shaped brush roller, for example. In the following description, it is assumed that the brush has a roller shape.
The brush roller 21 constituting the lubricant removing means 114Y contacts the surface of the photoreceptor 111Y and removes the lubricant by a mechanical action that mechanically rubs the surface of the photoreceptor 111Y. Specifically, It contacts the surface of the photoreceptor 111Y, rotates in the same direction as the rotation direction of the photoreceptor 111Y, and is driven to rotate at a constant speed.

[Brush roller]
The brush roller 21 constituting the lubricant removing means 114Y is, for example, a long brush body having a pile woven fabric structure in which a brush fiber body 23 made of a bundle of fibers is woven as a pile thread on a base fabric obtained by weaving warp and weft. The brushed surface may be spirally wound around the metal shaft 25 and bonded to form a roller shape. The length is formed by a plurality of brush fiber bodies 23 being densely implanted. A brush body having a flocking structure made of a woven cloth of a scale may be formed on the peripheral surface of the metal shaft 25.

  As the metal shaft 25, various conventionally known shafts can be used. Further, the diameter of the metal shaft 25 is not particularly limited, and the technique used for the conventional cleaning brush can be suitably applied. The metal shaft 25 is preferably grounded with respect to the photoreceptor 111Y.

The brush fiber body 23 is preferably made of a multifilament yarn composed of a bundle of a plurality of filament yarns. The material of the brush fiber body 23 is a synthetic material such as 6-nylon, 12-nylon, polyester, acrylic, vinylon, or the like. For example, a resin may be used, and a metal such as carbon or nickel may be kneaded for the purpose of increasing conductivity.
The thickness of the brush fiber body 23 is preferably 3 to 15 denier, and the hair length of the brush fiber body 23 is preferably 2 to 5 mm. Further, the planting density of the brush fiber body 23 in the brush body is set in a range of 40,000 to 500,000 pieces / square inch (40 k to 500 kF / inch ² ), thereby ensuring rigidity necessary for removing the lubricant. At the same time, it is possible to prevent the lubricant from being unevenly removed without forming a sparse portion of the brush fiber body 23. The electrical resistivity of the brush fiber body 23 is preferably 1 × 10 ⁷ Ω or less, and the Young's modulus of the brush fiber body 23 is preferably 1500 to 9800 N / mm ² .

  Examples of the shape of the brush fiber body 23 include a straight hair shape, a loop shape, or a shape having a spherical tip, and are not particularly limited. From the viewpoint of performing metal oxide treatment, straight hair It is preferable that it has a shape.

  In the present invention, the surface of the brush fiber body 23 is covered with a layer of metal oxide fine particles (hereinafter also referred to as “metal oxide layer”).

  The metal oxide layer only needs to be formed so as to cover at least the entire surface of the brush fiber body 23 in contact with the photoreceptor 111 </ b> Y, and covers the entire surface of the base fabric constituting the brush body and the brush fiber body 23. It may be formed, and may also be formed on the surface of the metal shaft 25.

  As the metal oxide fine particles constituting the metal oxide layer, silica particles, alumina particles, titanium oxide particles and the like can be used, and these can be used in combination.

  The surface of the metal oxide fine particles is preferably hydrophobized with a silane coupling agent.

Below, the specific example of a silane coupling agent is shown.
SS-1: CH ₂ = CHSi (CH ₃ ) (OCH ₃ ) ₂
SS-2: CH ₂ = CHSi (OCH ₃ ) ₃
SS-3: CH ₂ = CHSiCl _{3
SS-4: CH 2 = CHCOO} (CH 2) 2 Si (CH 3) (OCH 3) 2
_{SS-5: CH 2 = CHCOO} (CH 2) 2 Si (OCH 3) 3
_{SS-6: CH 2 = CHCOO} (CH 2) 2 Si (OC 2 H 5) (OCH 3) 2
_{SS-7: CH 2 = CHCOO} (CH 2) 3 Si (OCH 3) 3
_{SS-8: CH 2 = CHCOO} (CH 2) 2 Si (CH 3) Cl 2
_{SS-9: CH 2 = CHCOO} (CH 2) 2 SiCl 3
_{SS-10: CH 2 = CHCOO} (CH 2) 3 Si (CH 3) Cl 2
SS-11: CH ₂ ═CHCOO (CH ₂ ) ₃ SiCl _{3
SS-12: CH 2 = C} (CH 3) COO (CH 2) 2 Si (CH 3) (OCH 3) 2
_{SS-13: CH 2 = C} (CH 3) COO (CH 2) 2 Si (OCH 3) 3
_{SS-14: CH 2 = C} (CH 3) COO (CH 2) 3 Si (CH 3) (OCH 3) 2
_{SS-15: CH 2 = C} (CH 3) COO (CH 2) 3 Si (OCH 3) 3
_{SS-16: CH 2 = C} (CH 3) COO (CH 2) 2 Si (CH 3) Cl 2
_{SS-17: CH 2 = C} (CH 3) COO (CH 2) 2 SiCl 3
_{SS-18: CH 2 = C} (CH 3) COO (CH 2) 3 Si (CH 3) Cl 2
_{SS-19: CH 2 = C} (CH 3) COO (CH 2) 3 SiCl 3
_{SS-20: CH 2 = CHSi} (C 2 H 5) (OCH 3) 2
SS-21: CH ₂ ═C (CH ₃ ) Si (OCH ₃ ) _{3
SS-22: CH 2 = C} (CH 3) Si (OC 2 H 5) 3
_{SS-23: CH 2 = CHSi} (OCH 3) 3
_{SS-24: CH 2 = C} (CH 3) Si (CH 3) (OCH 3) 2
_{SS-25: CH 2 = CHSi} (CH 3) Cl 2
_{SS-26: CH 2 = CHCOOSi} (OCH 3) 3
_{SS-27: CH 2 = CHCOOSi} (OC 2 H 5) 3
_{SS-28: CH 2 = C} (CH 3) COOSi (OCH 3) 3
_{SS-29: CH 2 = C} (CH 3) COOSi (OC 2 H 5) 3
_{SS-30: CH 2 = C} (CH 3) COO (CH 2) 3 Si (OC 2 H 5) 3
_{SS-31: CH 2 = CHCOO} (CH 2) 2 Si (CH 3) 2 (OCH 3)
_{SS-32: CH 2 = CHCOO} (CH 2) 2 Si (CH 3) (OCOCH 3) 2
_{SS-33: CH 2 = CHCOO} (CH 2) 2 Si (CH 3) (ONHCH 3) 2
_{SS-34: CH 2 = CHCOO} (CH 2) 2 Si (CH 3) (OC 6 H 5) 2
_{SS-35: CH 2 = CHCOO} (CH 2) 2 Si (C 10 H 21) (OCH 3) 2
_{SS-36: CH 2 = CHCOO} (CH 2) 2 Si (CH 2 C 6 H 5) (OCH 3) 2
_{SS-37: CH 3 C (} CH 3) (CH 2) 2 Si (OCH 3) 3
_{SS-38: CH 3 C (} CH 3) (CH 2) 2 Si (OC 2 H 5) 3

  When the metal oxide layer is formed by the hydrophobized metal oxide fine particles, the degree of hydrophobicity of the brush fiber body 23 is preferably 5% or more.

The degree of hydrophobicity of the brush fiber body 23 is indicated by a measure (%) of wettability with respect to methanol measured by a methanol titration method.
Specifically, the degree of hydrophobicity of the brush fiber body 23 is determined by the formula: degree of hydrophobicity = {a / (a + 50)} × 100. In the formula, a represents the amount (ml) of methanol necessary to completely wet 0.1 g of brush fiber body 23 added to 50 ml of distilled water.

According to the image forming apparatus of the present invention provided with the lubricant removing means 114Y including the brush roller 21 having the brush fiber body 23 whose surface is coated with the metal oxide layer as described above, the life can be extended. At the same time, it is possible to suppress the occurrence of image unevenness and image flow in a high temperature and high humidity environment while having good toner cleaning properties.
This is considered to be due to the following reasons. That is, since the photoreceptor 111Y basically has a protective layer made of a curable resin, the lifetime can be extended. Further, by polishing the surface of the photoreceptor 111Y by the brush roller 21, the deteriorated lubricant film can be removed and a new lubricant film can always be formed, and thus good toner cleaning properties are ensured. Further, since the brush fiber body 23 is covered with the metal oxide layer, the polishing efficiency of the surface of the photoreceptor 111Y is controlled, and a necessary and sufficient amount of lubricant is ensured during cleaning, but the surface of the photoreceptor 111Y is secured. The deteriorated layer in the lubricant film that is formed can be removed with high uniformity.As a result, even if charging is performed by the proximity charging method in a high-temperature and high-humidity environment, image flow caused by deterioration of the lubricant and It is possible to suppress image defects such as image unevenness due to variations in the amount of lubricant present. Note that, when a brush roller having no metal oxide layer is used, it is inferior to the point that the lubricant film is made homogeneous, and therefore image flow and image unevenness cannot be sufficiently suppressed.
Further, according to the brush roller 21 on which the metal oxide layer is formed by the metal oxide fine particles whose surface has been hydrophobized, the polishing efficiency of the surface of the photoreceptor 111Y can be stably improved.

[Manufacturing method of brush roller]
The method for manufacturing a brush roller according to the present invention includes a step of producing a brush body having the brush fiber body 23 and a step of forming a metal oxide layer by performing metal plating on the entire surface of the brush body.
The step of forming the metal oxide layer is not limited to the brush body before being assembled into a roller shape, and may be performed after the brush body is assembled into a roller shape.

  The production process of the brush body can be performed by various conventionally known methods.

  For example, the metal oxide treatment method for the brush body can be performed as follows.

(1) Degreasing and hydrophilization treatment This degreasing and hydrophilization treatment is performed to remove residual oil on the surface of the brush fiber body 23 and improve wettability. Specifically, the degreasing and hydrophilization treatment is performed by immersing the brush body in a degreasing liquid. The degreasing liquid is not particularly limited, and for example, a degreasing liquid containing a surfactant as a main component can be used. The immersion temperature and the immersion time are not particularly limited. For example, the immersion temperature can be 50 ° C. to 70 ° C., and the immersion time can be 3 to 5 minutes. After immersion, it is preferable to perform hot water washing and water washing treatment in order to remove the surfactant remaining on the surface of the brush fiber body 23 and the like.

(2) Roughening treatment It is preferable to perform a roughening treatment (soft etching) on the surface of the brush fiber body 23 with a persulfate such as sodium persulfate after the degreasing / hydrophilic treatment. In this roughening treatment, the treatment temperature and treatment time are not particularly limited. For example, the treatment temperature can be 20 ° C. to 30 ° C., and the treatment time can be 1 to 3 minutes. After the roughening treatment, a water washing treatment is preferably performed in order to remove persulfate remaining on the surface of the brush fiber body 23 and the like. Furthermore, in order to remove remaining salts such as sodium compounds, acid neutralization treatment may be performed with an acid such as hydrochloric acid or sulfuric acid.

(3) Pre-dip Next, the brush body is immersed in a pre-dip solution. It does not specifically limit as a pre-dip liquid, For example, commercial items, such as "PD-301" (made by Hitachi Chemical Co., Ltd.), can be used. The immersion temperature and the immersion time are not particularly limited, and the immersion temperature can be 20 to 30 ° C. and the immersion time can be 1 to 2 minutes.

(4) Metal Oxide Treatment Then, in order to coat the brush fiber body 23 with metal oxide fine particles, the brush fiber body 23 is immersed in a reaction solution of metal oxide such as tetraethyl orthosilicate solution. The immersion temperature can be 90 to 110 ° C., and the immersion time can be 50 to 70 minutes. In addition, for the purpose of recovering / removing the remaining reaction solution of the metal oxide, a water washing treatment under an ultrasonic wave and a normal water washing treatment may be performed. The processing temperature and processing time at this time can be appropriately set as necessary.

  The use ratio of the metal oxide to the brush fiber body 23 may be an amount that allows at least the entire surface of the brush fiber body 23 in contact with the photoreceptor 111Y to be covered with the metal oxide layer. For example, it may be 3 to 8% with respect to the total weight of the brush fiber body 23.

  It can be observed with a scanning electron microscope (SEM) that metal oxide fine particles have adhered to the brush fiber body 23 to form a metal oxide layer.

(5) Drying treatment It is preferable to carry out a drying treatment after the metal oxide treatment. It does not specifically limit as a drying method, A conventionally well-known method is employable. The drying temperature can be, for example, 70 to 90 ° C., and the drying time can be, for example, 10 to 30 minutes.

  As described above, the lubricant removing unit is described as a roller-shaped brush roller. However, the brush constituting the lubricant removing unit may be a flat brush.

  The biting amount of the brush roller 21 with respect to the photoreceptor 111Y is preferably 0.5 to 1.5 mm. Further, the rotation speed of the brush roller 21 is, for example, 0.3 to 1.5 as a speed ratio with respect to the photoreceptor 111Y. Even if the rotation is the same direction as the rotation direction of the photoreceptor 111Y, the rotation in the opposite direction is performed. It may be.

[Transfer means]
The intermediate transfer body unit 130 includes an endless belt-shaped intermediate transfer body 131 and primary transfer rollers 133Y, 133M, 133C, which are disposed in contact with the photoreceptors 111Y, 111M, 111C, and 111Bk via the intermediate transfer body 131. 133Bk and a cleaning means 135 for the intermediate transfer member 131.
The primary transfer rollers 133Y, 133M, 133C, and 133Bk constituting the transfer unit are units that transfer the toner images formed on the photoconductors 111Y, 111M, 111C, and 111Bk to the intermediate transfer member 131.

  In this image forming apparatus 100, the toner images formed on the photoconductors 111Y, 111M, 111C, and 111Bk are transferred to the intermediate transfer body 131 by primary transfer rollers (primary transfer means) 133Y, 133M, 133C, and 133Bk. An intermediate transfer method is employed in which each toner image transferred onto the transfer member 131 is transferred to a transfer material P by a secondary transfer roller (secondary transfer means) 217. However, the toner image formed on the photosensitive member is not transferred. A direct transfer method in which the image is directly transferred onto a transfer material by a transfer unit may be employed.

  The intermediate transfer member 131 is wound around a plurality of rollers 137A, 137B, 137C, and 137D and is rotatably supported.

  In this image forming apparatus 100, the photosensitive member 111Y, the developing unit 117Y, the cleaning unit 119Y, the lubricant removing unit 114Y, the lubricant supplying unit 116Y, and the like are integrally coupled and are detachably attached to the apparatus main body (image cartridge). Forming unit). Alternatively, one or more members selected from the group consisting of a charging unit 113Y, an exposure unit 115Y, a developing unit 117Y, a lubricant removing unit 114Y, a lubricant supplying unit 116Y, a primary transfer roller 133Y, and a cleaning unit 119Y, and the photoreceptor 111Y are integrated. Alternatively, the process cartridge (image forming unit) may be configured as an example.

  The process cartridge 200 includes a housing 201 and photoreceptors 111Y, 111M, 111C, and 111Bk accommodated therein, charging units 113Y, 113M, 113C, and 113Bk, developing units 117Y, 117M, 117C, and 117Bk, and lubricant supply units 116Y and 116M. 116C, 116Bk, cleaning means 119Y, 119M, 119C, 119Bk and lubricant removing means 114Y, 114M, 114C, 114Bk, and an intermediate transfer body unit 130. The apparatus main body is provided with support rails 203L and 203R as means for guiding the process cartridge 200 into the apparatus main body. Thereby, the process cartridge 200 can be attached to and detached from the apparatus main body. These process cartridges 200 can be a single image forming unit configured to be detachable from the apparatus main body.

  The sheet feeding / conveying means 150 is provided so that the transfer material P in the sheet feeding cassette 211 can be conveyed to the secondary transfer roller 217 via a plurality of intermediate rollers 213A, 213B, 213C, 213D and a registration roller 215.

  The fixing unit 170 fixes the color image transferred by the secondary transfer roller 217. The paper discharge roller 219 is provided so as to be placed on the paper discharge tray 221 with the transfer material P that has been subjected to the fixing process interposed therebetween.

  In the image forming apparatus 100 configured as described above, a toner image is formed by the image forming units 110Y, 110M, 110C, and 110Bk. Specifically, first, lubricant is supplied to the surfaces of the photoreceptors 111Y, 111M, 111C, and 111Bk by the lubricant supply means 116Y, 116M, 116C, and 116Bk. Thereafter, the surfaces of the photoconductors 111Y, 111M, 111C, and 111Bk are discharged and charged negatively by the charging means 113Y, 113M, 113C, and 113Bk. Next, the surface of the photoconductors 111Y, 111M, 111C, and 111Bk is exposed based on the image signal by the exposure means 115Y, 115M, 115C, and 115Bk, and an electrostatic latent image is formed. Next, with the developing units 117Y, 117M, 117C, and 117Bk, toner is applied to the surface of the photoreceptors 111Y, 111M, 111C, and 111Bk and developed to form a toner image.

  Next, primary transfer rollers (primary transfer means) 133Y, 133M, 133C, and 133Bk are brought into contact with the rotating intermediate transfer member 131. As a result, the toner images of the respective colors formed on the photoreceptors 111Y, 111M, 111C, and 111Bk are sequentially transferred onto the rotating intermediate transfer member 131 to transfer the color image (primary transfer). During the image forming process, the primary transfer roller 133Bk is always in contact with the photoreceptor 111Bk. On the other hand, the other primary transfer rollers 133Y, 133M, and 133C are in contact with the corresponding photoreceptors 111Y, 111M, and 111C, respectively, only during color image formation.

  Then, after separating the primary transfer rollers 133Y, 133M, 133C, and 133Bk from the intermediate transfer member 131, the toner remaining on the surfaces of the photosensitive members 111Y, 111M, 111C, and 111Bk is cleaned with the cleaning units 119Y, 119M, 119C, and 119Bk. Remove with. Next, the lubricant adhering to the surfaces of the photoconductors 111Y, 111M, 111C, and 111Bk is removed by the lubricant removing means 114Y, 114M, 114C, and 114Bk. Thereafter, in preparation for the next image forming process, the lubricant is supplied to the surfaces of the photoreceptors 111Y, 111M, 111C, and 111Bk by the lubricant supply means 116Y, 116M, 116C, and 116Bk, and if necessary, the photoreceptors 111Y, 111M, and 111C. , 111Bk is neutralized by a neutralizing means (not shown) and then negatively charged by charging means 113Y, 113M, 113C, 113Bk. As described above, the image forming apparatus 100 is configured to remove the lubricant having a charging history before being charged on the surface of the photoconductor 111 for each image forming process.

  On the other hand, a transfer material P (for example, a support for carrying a final image such as plain paper or a transparent sheet) accommodated in a paper feed cassette 211 is fed by a paper feed / conveying means 150 and a plurality of intermediate rollers 213A and 213B. 213C, 213D, and registration rollers 215, and then conveyed to a secondary transfer roller (secondary transfer means) 217. Then, the secondary transfer roller 217 is brought into contact with the rotating intermediate transfer member 131 to transfer the color image onto the transfer material P in a lump (secondary transfer). The secondary transfer roller 217 contacts the intermediate transfer member 131 only when performing secondary transfer on the transfer material P. Thereafter, the transfer material P on which the color images are collectively transferred is separated at a portion where the curvature of the intermediate transfer member 131 is high.

  The transfer material P onto which the color images have been transferred in this way is fixed by the fixing unit 170 and then sandwiched by the paper discharge roller 219 and placed on the paper discharge tray 221 outside the apparatus. Further, after separating the transfer material P onto which the color image has been collectively transferred from the intermediate transfer member 131, the residual toner on the intermediate transfer member 131 is removed by the cleaning unit 135.

〔toner〕
The toner used in the image forming apparatus of the present invention is not particularly limited, and includes toner particles containing a binder resin and a colorant. The toner particles may include other components such as a release agent as desired. May be contained.
The toner particles constituting the toner preferably have a volume average particle diameter of 2 to 8 μm from the viewpoint of achieving high image quality.

  The method for producing the toner is not particularly limited. For example, a known pulverization method, a wet melt spheronization method prepared in a dispersion medium, suspension polymerization, dispersion polymerization, emulsion polymerization aggregation method and the like are known. And the like.

  In addition, an appropriate amount of inorganic fine particles such as silica and titania having an average particle diameter of about 10 to 300 nm and an abrasive of about 0.2 to 3 μm can be externally added to the toner particles as external additives.

The toner can be used as a magnetic or nonmagnetic one-component developer, but may be mixed with a carrier and used as a two-component developer.
In the case where the toner is used as a two-component developer, the carrier may be a conventionally known material such as a ferromagnetic metal such as iron, an alloy such as ferromagnetic metal and aluminum and lead, and a compound of ferromagnetic metal such as ferrite and magnetite. In particular, ferrite is preferable.

(Image forming method)
The image forming apparatus of the present invention can be used in an electrophotographic image forming method in which charging is performed by a proximity charging method. Specifically, the image forming method includes a proximity charging process in which the surface of the photoconductor is charged by a proximity charging method, an exposure process in which the photoconductor charged by the proximity charging process is exposed, and a photosensitive material exposed in the exposure process. A developing process for supplying toner to the body to form a toner image, a transfer process for transferring the toner image formed on the photoreceptor, a lubricant supplying process for supplying a lubricant to the surface of the photoreceptor, and a lubricant for the photoreceptor. A lubricant removing step for removing the toner from the surface of the toner, and a cleaning step for removing the toner remaining on the surface of the photoreceptor.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited only to a following example. In the following, “part” means “part by mass”.

[Photosensitive body preparation example 1]
As shown below, an intermediate layer and an organic photosensitive layer comprising a charge generation layer and a charge transport layer are laminated in this order on a conductive support, and a protective layer is formed as a surface layer on the organic photosensitive layer. A layered photoreceptor [1] was prepared.
The surface of a cylindrical aluminum support having a diameter of 60 mm was cut to prepare a conductive support [1] having a fine and rough surface.

(A) Formation of the intermediate layer A dispersion having the following composition was diluted twice with the same mixed solvent, allowed to stand overnight and then filtered (filter; using a lymesh 5 μm filter manufactured by Nihon Pall Co., Ltd.). 1] was prepared.
Binder resin: Polyamide resin “CM8000” (manufactured by Toray Industries, Inc.) 1 part Metal oxide fine particles: Titanium oxide “SMT500SAS” (manufactured by Teica) 3 parts Solvent: Methanol 10 parts Batch using a sand mill as a disperser for 10 hours Was distributed.
An intermediate layer [1] having a dry film thickness of 2 μm was formed on the conductive support [1] using the intermediate layer forming coating solution [1] by dip coating.

(B) Formation of charge generation layer Charge generation material: 20 parts of the following pigment (CG-1), binder resin: 10 parts of polyvinyl butyral resin “# 6000-C” (manufactured by Denki Kagaku Kogyo), solvent: t-butyl acetate 700 parts of solvent: 300 parts of 4-methoxy-4-methyl-2-pentanone was mixed and dispersed for 10 hours using a sand mill to prepare a charge generation layer forming coating solution [1]. This charge generation layer forming coating solution [1] was applied onto the intermediate layer [1] by a dip coating method to form a charge generation layer [1] having a dry film thickness of 0.3 μm.

<Synthesis of Pigment (CG-1)>
(1) Synthesis of amorphous titanyl phthalocyanine 1,3-diiminoisoindoline; 29.2 parts by mass are dispersed in 200 parts by mass of o-dichlorobenzene, and titanium tetra-n-butoxide; 20.4 parts by mass are added. It heated at 150-160 degreeC for 5 hours under nitrogen atmosphere. After allowing to cool, the precipitated crystals were filtered, washed with chloroform, washed with 2% aqueous hydrochloric acid, washed with water, washed with methanol, and dried to obtain 26.2 parts by mass (yield 91%) of crude titanyl phthalocyanine.
Next, the crude titanyl phthalocyanine was dissolved by stirring for 1 hour in 250 parts by mass of concentrated sulfuric acid at 5 ° C. or less, and this was poured into 5000 parts by mass of water at 20 ° C. The precipitated crystals were filtered and sufficiently washed with water to obtain 225 parts by mass of a wet paste product.
This 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%).

(2) Synthesis of (2R, 3R) -2,3-butanediol adduct titanyl phthalocyanine (CG-1) 10.0 parts by mass of the above amorphous titanyl phthalocyanine and (2R, 3R) -2,3-butanediol 0 .94 parts by mass (0.6 equivalent ratio) (equivalent ratio is equivalent to titanyl phthalocyanine, hereinafter the same) was mixed in 200 parts by mass of orthochlorobenzene (ODB), and heated and stirred at 60 to 70 ° C. for 6.0 hours. After standing overnight, methanol was added to the reaction solution, and the resulting crystals were filtered. The crystals after filtration were washed with methanol (a pigment containing (2R, 3R) -2,3-butanediol adduct titanyl phthalocyanine). CG-1: 10.3 mass parts was obtained. In the X-ray diffraction spectrum of the pigment (CG-1), there are clear peaks at 8.3 °, 24.7 °, 25.1 °, and 26.5 °. There is a peak in the 576 and 648 in the mass spectra, O-Ti-O both absorption appears Ti = O near 970 cm ^-1, around 630 cm ^-1 in the IR spectrum. In addition, since thermal analysis (TG) has a mass loss of about 7% at 390 to 410 ° C., a 1: 1 adduct and a non-adduct (addition) of titanyl phthalocyanine and (2R, 3R) -2,3-butanediol (Not) presumed to be a mixture of titanyl phthalocyanine.
It was 31.2 m < ² > / g when the BET specific surface area of the obtained pigment (CG-1) was measured with the flow type specific surface area automatic measuring apparatus (Micrometrics flow soap type: Shimadzu Corporation).

(C) Formation of charge transport layer Charge transport material: 225 parts of the following compound A, binder resin: 300 parts of polycarbonate resin “Z300” (manufactured by Mitsubishi Gas Chemical), antioxidant: “Irganox 1010” (manufactured by Ciba Geigy Japan) 6 parts , Solvent: 1600 parts of THF (tetrahydrofuran), solvent: 400 parts of toluene, 1 part of silicone oil “KF-50” (manufactured by Shin-Etsu Chemical Co., Ltd.) are mixed and dissolved to prepare a coating solution [1] for forming a charge transport layer. did.
The charge transport layer forming coating solution [1] was applied onto the charge generation layer [1] using a circular slide hopper coating apparatus to form a charge transport layer [1] having a dry film thickness of 20 μm.

(D) Formation of protective layer (1) Production of metal oxide fine particles Tin oxide (manufactured by CIK Nanotech, number average primary particle size: 20 nm, volume resistivity: 1.05 × 10 ⁵ (Ω · cm)) 100 mass A mixed solution of 30 parts by mass of the above exemplified compound (S-15) as a surface treating agent and 300 parts by mass of a mixed solvent of toluene / isopropyl alcohol = 1/1 (mass ratio) together with zirconia beads is placed in a sand mill, and about 40 The mixture was stirred at 1500 ° C. at a rotational speed of 1500 rpm, and the above processing mixture was taken out, put into a Henschel mixer, stirred at a rotational speed of 1500 rpm for 15 minutes, and then dried at 120 ° C. for 3 hours to thereby remove the radical polymerizable functional group. Finishing the surface treatment of tin oxide with the compound having it, surface-treated tin oxide was obtained. This is designated as metal oxide fine particles [1]. The surface of the tin oxide particles was coated with the exemplified compound (S-15) by the surface treatment with the compound having the radical polymerizable functional group.

(2) Curing Polymerizable compound: 100 parts by mass of the above exemplified compound (M1), 150 parts by mass of metal oxide fine particles [1], solvent: 510 parts by mass of sec-butanol, solvent: 0.3 part by mass of THF (tetrahydrofuran) Were mixed under shading to obtain a curable composition, and this was dispersed for 5 hours using a sand mill as a disperser. Then, 12.5 parts by mass of a polymerization initiator: “Irgacure 379” (manufactured by BASF Japan Ltd.) In addition, the mixture was dissolved by stirring under light shielding to prepare a coating solution [1] for forming a protective layer. The protective layer-forming coating solution [1] was applied onto the charge transport layer [1] using a circular slide hopper coating device to form a coating film. Then, this coating film was dried at room temperature for 15 minutes, and the separation distance between the light source and the coating film was set to 10 mm under a nitrogen flow using a xenon lamp, and irradiated with ultraviolet rays at a lamp output of 1 kW for 1 minute to dry. A protective layer [1] having a thickness of 3.0 μm was formed to produce a photoreceptor [1]. The universal hardness of the protective layer in this photoreceptor [1] was 240 N / mm ² .

[Photoconductor Preparation Example 2]
In Preparation Example 1 of the photoreceptor, 20 parts by mass of filler: “Eposter S6” (manufactured by Nippon Shokubai Co., Ltd.) was added to the curable composition, and the ultraviolet irradiation intensity was changed to 2 kW. A photoreceptor [2] was produced. The universal hardness of the protective layer in this photoreceptor [2] was 280 N / mm ² .

[Photoconductor Preparation Example 3]
In Preparation Example 1 of the photoreceptor, 20 parts by mass of filler: “Eposter MS” (manufactured by Nippon Shokubai Co., Ltd.) was added to the curable composition, and the ultraviolet irradiation intensity was changed to 2 kW. A photoreceptor [3] was produced. The universal hardness of the protective layer in this photoreceptor [3] was 280 N / mm ² .

[Photoconductor Preparation Example 4]
In Preparation Example 1 of the photoreceptor, in the curing composition, “Irgacure 819” (manufactured by BASF Japan) was used instead of “Irgacure 379” as a polymerization initiator, and the irradiation intensity of ultraviolet rays was changed to 3 kW. A photoconductor [4] was prepared in the same manner as described above. The universal hardness of the protective layer in this photoreceptor [4] was 400 N / mm ² .

[Photoconductor Preparation Example 5]
In Preparation Example 1 of the photoreceptor, 20 parts by mass of a filler: “Eposter S6” (manufactured by Nippon Shokubai Co., Ltd.) was added to the curing composition, and “Irgacure 819” (BASF) was used as a polymerization initiator instead of “Irgacure 379”. The photoconductor [5] was produced in the same manner except that the ultraviolet irradiation intensity was changed to 3 kW and the ultraviolet irradiation time was changed to 2 minutes. The universal hardness of the protective layer in this photoreceptor [5] was 550 N / mm ² .

[Photoconductor Preparation Example 6]
The same procedure as in Photoconductor Preparation Example 1 except that 10.0 parts by mass of “Irgacure 819” (BASF Japan) was used as the polymerization initiator instead of 12.5 parts by mass of “Irgacure 379”. Thus, a photoreceptor [6] was produced. The universal hardness of the protective layer in this photoreceptor [6] was 200 N / mm ² .

[Photoconductor Preparation Example 7]
In Preparation Example 1 of the photoreceptor, 20 parts by mass of a filler: “Eposter S6” (manufactured by Nippon Shokubai Co., Ltd.) was added to the curing composition, and “Irgacure 819” (BASF) was used as a polymerization initiator instead of “Irgacure 379”. A photoconductor [7] was prepared in the same manner except that the ultraviolet irradiation intensity was changed to 2 kW. The universal hardness of the protective layer in this photoreceptor [7] was 240 N / mm ² .

[Photosensitive member production example 8]
Photoreceptor [8] was produced in the same manner as in Photoreceptor Production Example 1 except that “Irgacure 819” (manufactured by BASF Japan) was used as the polymerization initiator instead of “Irgacure 379”. . The universal hardness of the protective layer in this photoreceptor [8] was 180 N / mm ² .

[Brush roller production example 1]
A base fabric made of a woven fabric obtained by weaving warp yarns and weft yarns, and a brush body in which pile yarns (brush fiber bodies) are woven in a W shape around the weft yarns of the base fabric were used.
The brush fiber body was made of a multifilament yarn made of nylon fiber, and a straight hair yarn having a circular cross section was used. The fiber diameter of the brush fiber body was 30 μm, the fineness was 6 dtex, the brush density was 110 kF / inch (10%), and the length of the brush fiber body (distance from the root portion to the tip) was 5 mm. In addition, a backing layer (thickness: 0.1 mm) made of NBR (acrylonitrile-butadiene rubber) was formed on the base fabric. Further, as the warp and weft, those made of polyester fiber were used.

The brush body was subjected to metal oxide treatment as follows.
First, in order to remove residual oil on the surface of the brush fiber body and improve wettability, the brush body was immersed in a degreasing solution “CLC-601” (manufactured by Hitachi Chemical Co., Ltd.). The concentration of this degreasing solution was 50 ml / l, the solution temperature was 60 ° C., and the immersion time was 4 minutes.

  Furthermore, in order to remove the degreasing liquid remaining on the brush fiber body, hot water washing and water washing treatment were performed. The temperature of the hot water bath during hot water washing was 50 ° C., and the treatment time was 1 minute. Moreover, the temperature of the water bath at the time of the water washing process was normal temperature, and the process time was 3 minutes.

  Next, the surface of the brush fiber body was roughened (soft etching) using sodium persulfate. The treatment temperature was 25 ° C. and the treatment time was 2 minutes. Further, with the purpose of recovering and removing the remaining sodium persulfate, washing with recovered water and washing with running water were continued. The treatment time was 1 minute each. Subsequently, in order to remove the remaining sodium compound, acid neutralization treatment was performed with sulfuric acid. At this time, the temperature of sulfuric acid was 25 ° C., and the treatment time was 1 minute. For the purpose of recovering and removing the remaining sulfuric acid, washing with recovered water and washing with running water were continued. The treatment time was 1 minute each.

  Next, the brush body was immersed in pre-dip liquid “PD-301” (manufactured by Hitachi Chemical Co., Ltd., concentration 250 g / l). The immersion time was 2 minutes, and the temperature of the pre-dip solution was 25 ° C.

  Further, in order to form a metal oxide layer, it was immersed in a tetraethyl orthosilicate solution. The immersion temperature was 100 ° C. and the immersion time was 60 minutes. Then, it was dried, and in order to collect and remove the remaining reaction solution, it was washed with water for 15 seconds under ultrasonic waves, and washed with running water for 1 minute. Finally, after wiping off the water, the brush body was dried at a drying temperature of 80 ° C. and a drying time of 20 minutes. Let the brush body in which this metal oxide layer was formed be a metal oxide layer containing brush body [1].

  The metal oxide layer-containing brush body [1] was wound around and adhered to a metal shaft (SUM22) having an outer diameter of 6 mm to produce a brush roller [1].

[Brush roller production example 2]
In Brush Roller Production Example 1, the metal oxide layer-containing brush body [1] was mixed with a surface treatment agent: 30 parts by mass of the exemplified compound (SS-15) and toluene / isopropyl alcohol = 1/1 (mass ratio). It was immersed for 15 minutes in the mixed liquid which mixed 300 mass parts in the state rotated at the rotational speed of 100 rpm. The temperature of this mixture was kept at 40 ° C. After taking out from this liquid mixture, the surface treatment by a surface treating agent was complete | finished by drying at 120 degreeC for 3 hours, and, thereby, brush roller [2] was obtained.

[Production Example 3 of Brush Roller]
In brush roller production example 2, a brush roller [3] was obtained in the same manner except that the exemplified compound (SS-37) was used as the surface treatment agent.

[Brush roller production example 4]
A brush roller [4] was obtained in the same manner as in Brush Roller Production Example 1, except that an n-hexane solution of aluminum isopropoxide was used instead of the tetraethyl orthosilicate solution.

[Brush roller production example 5]
Brush roller [5] was obtained in the same manner as in Production Example 3 of Brush Roller except that an n-hexane solution of aluminum isopropoxide was used instead of the tetraethyl orthosilicate solution.

[Brush roller production example 6]
A brush roller [6] was obtained in the same manner as in Brush roller production example 1, except that a tetraethyl orthotitanate solution was used instead of the tetraethyl orthosilicate solution.

[Brush roller production example 7]
A brush roller [7] was obtained in the same manner as in Brush roller production example 3, except that a tetraethyl orthotitanate solution was used instead of the tetraethyl orthosilicate solution.

[Brush roller production example 8]
In the same manner as in Brush Roller Production Example 1, except that the treatment for immersing in the pre-dip solution and the treatment for immersing in the tetraethyl orthosilicate solution for forming the metal oxide layer were not performed, the brush roller [8] Got.

<Example 1: Production Example 1 of image forming apparatus>
The photoreceptor [1] was mounted on the image forming apparatus “bizhub C353” (manufactured by Konica Minolta Co., Ltd.), and the image forming unit was remodeled so as to be charged by a charging roller. Further, the brush roller [1] was installed on the upstream side of the cleaning unit under the following conditions, and the lubricant supply unit having the following specifications was arranged on the downstream side of the cleaning unit and the upstream side of the charging unit. This is referred to as an image forming apparatus [1].

-Installation conditions for lubricant removal means-
The brush roller [1] was installed with respect to the photoreceptor so that the biting amount was 0.8 mm, and was rotated at a peripheral speed ratio of 0.6 in the same direction as the rotation direction of the photoreceptor. The brush roller was grounded via a metal shaft.

-Specifications of lubricant supply means-
As the lubricant supply means, an apparatus constituted by a lubricant stock and an application member composed of a straight hair type brush roller was used. This brush roller uses carbon-containing nylon fiber “SA-7” (manufactured by Toray Industries, Inc.) as filament yarn, the thickness of the brush fiber is 3 denier, the planting density of the brush fiber is 120 kF / inch ² , and the hair length of the brush fiber is 3 A ribbon-shaped material having a diameter of 0.0 mm is spirally wound around a metal shaft (SUM22) having an outer diameter of 6 mm.
-Installation conditions for lubricant supply means-
The brush roller was installed with respect to the photoreceptor so that the biting amount was 1 mm, and was rotated at a peripheral speed ratio of 0.6 in the direction opposite to the rotation direction of the photoreceptor. The brush roller was grounded via a metal shaft. The pressing force of the lubricant stock against the brush roller was 2 N / m ² . The type of lubricant was zinc stearate.

<Examples 2-8, Comparative Example 3>
The image forming apparatuses [2] to [8] and [11] were prepared in the same manner as in the image forming apparatus of Example 1 except that the photosensitive member and the brush roller described in Table 1 were installed. Produced.

<Comparative Examples 2 and 3>
In the first example of manufacturing the image forming apparatus of Example 1, the image forming apparatus [9], [9], [9], [1] are similarly installed except that the brush roller [1] is not installed and the photosensitive member described in Table 1 is installed. 10].

  The following evaluation was performed using the image forming apparatuses [1] to [11]. The results are shown in Table 1.

(1) Image flow evaluation In a high-temperature and high-humidity environment (temperature of 30 ° C., humidity of 85% RH), after 2000 character charts corresponding to a printing rate of 5% were printed continuously, and then one halftone image was printed The power was turned off and left for 8 hours, and then turned on to print 20 A3 halftone images continuously.
The image flow was evaluated by the number of sheets when the halftone image was restored to the level of the halftone image printed before leaving. In this invention, the case where it recovered within the 7th sheet was evaluated as the pass. Note that the seventh sheet is based on the seventh sheet because the rotation speed of the photoconductor for image stabilization performed when the apparatus is started up is equivalent to the seventh sheet printing of A3 paper. This is because it is considered that image deterioration due to image flow does not occur from the first printing.

(2) Evaluation of photoconductor depletion amount After printing 100,000 sheets of a character chart corresponding to a printing rate of 5%, the thickness of the protective layer of the photoconductor was measured, and the depletion amount of the protective layer was calculated. The film thickness was measured using an eddy current film thickness measuring machine “Fischer Scope MMS PC” (manufactured by Fisher Instruments). In the present invention, the case where the amount of wear of the protective layer was within 1.0 μm was evaluated as acceptable.

21 Brush roller 23 Brush fiber body 25 Metal shaft 30 Blade member 31 Support member 100 Image forming apparatuses 110Y, 110M, 110C, 110Bk Image forming units 111Y, 111M, 111C, 111Bk Photosensitive members 113Y, 113M, 113C, 113Bk Charging means 114Y 114M, 114C, 114Bk Lubricant removing means 115Y, 115M, 115C, 115Bk Exposure means 116Y, 116M, 116C, 116Bk Lubricant supply means 117Y, 117M, 117C, 117Bk Developing means 119Y, 119M, 119C, 119Bk Cleaning means 130 Intermediate transfer member Unit 131 Intermediate transfer member 133Y, 133M, 133C, 133Bk Primary transfer roller (transfer means)
135 Cleaning means 137A, 137B, 137C, 137D Roller 150 Feeding means 170 Fixing means 200 Process cartridge 201 Housing 203R, 203L Support rail 211 Feed cassettes 213A, 213B, 213C, 213D Intermediate roller 215 Registration roller 217 Secondary transfer Roller (transfer means)
219 Paper discharge roller 221 Paper discharge tray P Transfer material SC Document image reading device

Claims (6)

A photosensitive member having a protective layer made of a curable resin; a charging unit of a proximity charging method that charges the surface of the photosensitive member; an exposing unit that exposes the photosensitive member charged by the charging unit; and an exposure unit that exposes the photosensitive member. Developing means for supplying toner to the photoreceptor to form a toner image; transfer means for transferring the toner image formed on the photoreceptor; lubricant supply means for supplying a lubricant to the surface of the photoreceptor; An image forming apparatus comprising: a cleaning unit that removes toner remaining on the surface of a photoreceptor; and a lubricant removing unit that removes the lubricant from the surface of the photoreceptor.
The lubricant removing means comprises a brush having a brush fiber body in contact with the photoconductor, and at least the surface of the brush fiber body in contact with the photoconductor is covered with a layer of metal oxide fine particles. Image forming apparatus.   The image forming apparatus according to claim 1, wherein the surface of the metal oxide fine particles is hydrophobized by a silane coupling agent.   The image according to claim 1 or 2, wherein the protective layer of the photoconductor contains metal oxide fine particles surface-treated with a surface treatment agent comprising a compound having a reactive organic group. Forming equipment.   4. The image forming apparatus according to claim 1, wherein the protective layer of the photoreceptor contains organic fine particles made of a compound having a melamine structure.   The image forming apparatus according to any one of claims 1 to 4, wherein the metal oxide fine particles are made of one or more selected from the group consisting of silica particles, alumina particles, and titanium oxide particles. . The protective layer of the photoreceptor, the image forming apparatus according to any one of claims 1 to 5, the universal hardness is characterized in that it is of 280N / mm ² or more 600N / mm ² or less.

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