JP2011197449A - Process cartridge and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process cartridge suppressed in image defect.SOLUTION: The process cartridge includes: an image holder 58; a charging means 56 coming in contact with the image holder 58 to electrostatically charge a surface of the image holder 58; and a resin film 40 which is held between the image holder 58 and the charging means 56 so as to be separated, and the process cartridge is attached to and detached from an image forming apparatus. In the resin film, a difference between an oxygen atom content of a surface 42 coming in contact with the image holder 58 measured by X-ray electron spectroscopy (XPS) and an oxygen atom content measured inside the face 42 by X-ray electron spectroscopy is 1 to 20 atom%, and the wet tension of the surface 42 coming in contact with the image holder 58 is 35 to 55 mN/m.

Description

  The present invention relates to a process cartridge and an image forming apparatus.

An image forming apparatus using an electrophotographic system forms a charge on an image carrier (for example, an electrophotographic photosensitive member), forms an electrostatic latent image with a laser or the like that modulates an image signal, and then uses charged toner. The electrostatic latent image is developed into a toner image. Then, a transferred image is obtained by electrostatically transferring the toner image to a recording material medium via an intermediate transfer member or directly.
As described above, in an image forming apparatus using an electrophotographic method, a charging process for forming a charge on an image carrier (for example, an electrophotographic photosensitive member) is performed. One type of charging member that performs this charging process is a contact-type charging member. Such a contact-type charging member generally has a merit that a small amount of ozone is generated as compared with a corotron or a scorotron, which is a non-contact-type charging member, generally with a small applied current.

In recent years, as a technique related to an image forming apparatus using a contact-type charging member, a charging history of an image carrier due to contact between a charging member (for example, a charging roll) and an image carrier (for example, an electrophotographic photosensitive member) is generated. Suppression technologies are being studied.
Specifically, a technique in which powder is applied between the charging unit and the image holding member (see, for example, Patent Document 1), or a charging column level is provided between the charging unit and the image holding member. A technique (for example, see Patent Document 2) in which a powder composed of a substance located on the plus side of a substance existing on the body surface is known.
In addition, a movable sheet is sandwiched between the charging means and the image carrier, and the relationship between the charge train of the image carrier and the movable sheet and the surface resistivity of the surface of the movable sheet that contacts the electrophotographic photosensitive member are specified. Has been proposed (see, for example, Patent Document 3).

  Further, from the viewpoint of preventing contamination, a technique is known in which a sheet is sandwiched between a charging member (for example, a charging roll) and an image holding body (for example, an electrophotographic photosensitive member) (for example, see Patent Document 4). .

Japanese Patent Laid-Open No. 3-103878 JP-A-7-84432 JP 2002-258719 A JP 2004-140770 A

  The object of the present invention is to measure the oxygen atom content measured by X-ray electron spectroscopy (XPS) on the surface of the resin film in contact with the image carrier and X-ray electron spectroscopy (XPS) inside the surface. When the difference in oxygen atom content is outside the range of 1 atom% or more and 20 atom% or less and / or when the wetting tension of the surface in contact with the image carrier is outside the range of 35 mN / m or more and 55 mN / m or less, An object of the present invention is to provide a process cartridge and an image forming apparatus in which image defects are suppressed.

The above problem is solved by the following means. That is,
The invention according to claim 1
An image carrier,
Charging means for charging the surface of the image carrier in contact with the image carrier;
The oxygen atom content measured by X-ray electron spectroscopy (XPS) of the surface that is sandwiched between the image carrier and the charging unit and is in contact with the image carrier, and on the inner side of the surface Resin film having a difference in oxygen atom content measured by X-ray electron spectroscopy (XPS) of 1 atom% or more and 20 atom% or less and a wetting tension of a surface in contact with the image carrier of 35 mN / m or more and 55 mN / m or less When,
And a process cartridge that is detachable from the image forming apparatus.

The invention according to claim 2
2. The process cartridge according to claim 1, wherein at least a surface of the resin film in contact with the image carrier has a polyolefin as a main component.

The invention according to claim 3
3. The process cartridge according to claim 1, wherein the resin film has an oxygen atom content of 1 atom% or more and 20 atom% or less measured by X-ray electron spectroscopy (XPS) on a surface in contact with the image carrier. is there.

The invention according to claim 4
4. The process cartridge according to claim 1, wherein the image carrier has a charge generation layer and a charge transport layer having a thickness of 30 μm or more in this order on a conductive substrate. 5. .

The invention according to claim 5
An image carrier,
Charging means for charging the surface of the image carrier in contact with the image carrier;
The oxygen atom content measured by X-ray electron spectroscopy (XPS) of the surface that is sandwiched between the image carrier and the charging unit and is in contact with the image carrier, and on the inner side of the surface Resin film having a difference in oxygen atom content measured by X-ray electron spectroscopy (XPS) of 1 atom% or more and 20 atom% or less and a wetting tension of a surface in contact with the image carrier of 35 mN / m or more and 55 mN / m or less When,
Latent image forming means for forming a latent image on the surface of the charged image carrier;
Developing means for developing a latent image formed on the surface of the image carrier with toner to form a toner image;
Transfer means for transferring a toner image formed on the surface of the image carrier to a recording medium;
An image forming apparatus having

The invention according to claim 6
The image forming apparatus according to claim 5, wherein at least a surface in contact with the image carrier in the resin film has a polyolefin as a main component.

The invention according to claim 7 provides:
The image forming apparatus according to claim 5, wherein the resin film has an oxygen atom content of 1 atom% or more and 20 atom% or less measured by X-ray electron spectroscopy (XPS) on a surface in contact with the image carrier. It is.

The invention according to claim 8 provides:
The image forming apparatus according to claim 5, wherein the image carrier has a charge generation layer and a charge transport layer having a thickness of 30 μm or more in this order on a conductive substrate. is there.

  According to the first aspect of the present invention, the oxygen atom content measured by X-ray electron spectroscopy (XPS) of the surface of the resin film in contact with the image carrier, and X-ray electron spectroscopy (XPS) inside the surface And when the difference in oxygen atom content measured by 1) is out of the range of 1 atom% to 20 atom% and / or the wetting tension of the surface in contact with the image carrier is out of the range of 35 mN / m to 55 mN / m. In comparison, image defects are suppressed.

  According to the invention which concerns on Claim 2, an image defect is suppressed compared with the case where the surface which contact | connects the image holding body of a resin film does not have polyolefin as a main component.

  According to the invention of claim 3, the oxygen atom content measured by X-ray electron spectroscopy (XPS) of the surface in contact with the image carrier of the resin film is out of the range of 1 atom% or more and 20 atom% or less. Thus, image defects are suppressed.

  According to the fourth aspect of the present invention, image defects are suppressed even when the thickness of the charge transport layer is 30 μm or more, compared to the case where the present configuration is not provided.

  According to the invention of claim 5, the oxygen atom content measured by X-ray electron spectroscopy (XPS) of the surface of the resin film in contact with the image carrier, and the X-ray electron spectroscopy (XPS) inside the surface And when the difference in oxygen atom content measured by 1) is out of the range of 1 atom% to 20 atom% and / or the wetting tension of the surface in contact with the image carrier is out of the range of 35 mN / m to 55 mN / m. In comparison, image defects are suppressed.

  According to the invention which concerns on Claim 6, an image defect is suppressed compared with the case where the surface which contact | connects the image holding body of a resin film does not have polyolefin as a main component.

  According to the seventh aspect of the present invention, the oxygen atom content measured by X-ray electron spectroscopy (XPS) of the surface of the resin film in contact with the image carrier is outside the range of 1 atom% or more and 20 atom% or less. Thus, image defects are suppressed.

  According to the eighth aspect of the present invention, image defects are suppressed even when the thickness of the charge transport layer is 30 μm or more, compared to the case where the present configuration is not provided.

It is a schematic cross section showing an example of a layer configuration of a charging member in the present embodiment. It is a schematic cross section which shows another example of the layer structure of the charging member in this embodiment. It is a schematic cross-sectional view showing an example of an image carrier (electrophotographic photoreceptor) in the present embodiment. It is a schematic cross section which shows another example of the image holding body (electrophotographic photosensitive member) in this embodiment. It is a schematic cross section which shows another example of the image holding body (electrophotographic photosensitive member) in this embodiment. It is a schematic cross section which shows another example of the image holding body (electrophotographic photosensitive member) in this embodiment. It is a schematic cross section which shows an example of the resin film in this embodiment. It is a schematic cross section showing an example of a resin film, a charging member, and an image carrier in the present embodiment. It is a schematic cross section showing an example of a process cartridge according to the present embodiment. 1 is a schematic cross-sectional view illustrating an example of an image forming apparatus according to an embodiment. It is a schematic cross section showing another example of the image forming apparatus according to the present embodiment. It is a schematic cross section showing another example of the image forming apparatus according to the present embodiment.

Embodiments of a process cartridge and an image forming apparatus according to the present invention will be described below.
The process cartridge according to the present embodiment can be detached between the image carrier, a charging unit that contacts the image carrier and charges the surface of the image carrier, and the image carrier and the charging unit. The oxygen atom content measured by X-ray electron spectroscopy (XPS) of the surface sandwiched and in contact with the image carrier, and the oxygen atom content measured by X-ray electron spectroscopy (XPS) inside the surface A resin film having a difference of 1 atom% or more and 20 atom% or less and a wetting tension of a surface in contact with the image carrier of 35 mN / m or more and 55 mN / m or less, and is attached to or detached from the image forming apparatus.
Further, the image forming apparatus according to the present embodiment is separated between the image carrier, the charging unit that contacts the image carrier and charges the surface of the image carrier, and the image carrier and the charging unit. The oxygen atom content measured by X-ray electron spectroscopy (XPS) on the surface in contact with the image carrier, and the oxygen atoms measured by X-ray electron spectroscopy (XPS) inside the surface A resin film having a content difference of 1 atom% or more and 20 atom% or less and a wetting tension of a surface in contact with the image carrier of 35 mN / m or more and 55 mN / m or less, and a latent image on the surface of the charged image carrier A latent image forming means for forming a toner image, a developing means for developing a latent image formed on the surface of the image carrier with toner to form a toner image, and a toner image formed on the surface of the image carrier. Transfer to medium Having a transfer means.

In general, when using a contact-type charging member that contacts an image carrier (for example, an electrophotographic photosensitive member) and charges the surface of the image carrier, the charging member is disposed in contact with the image carrier. Charges may be generated due to friction, peeling, or the like at the portion where the charging member and the image carrier are in contact with each other in the process of production to physical distribution. In the present specification, the phenomenon in which charges are generated in this way is also referred to as “charging history occurs”.
The charges generated in this manner are accumulated on the surface of the image carrier (that is, a charge history is accumulated on the surface of the image carrier), and when the image forming apparatus is used for the first time, the photosensitivity unevenness of the image carrier is caused. Sometimes. As a result, image defects such as toner color streaks or white streaks (hereinafter sometimes collectively referred to as “color streaks”) corresponding to the contact area between the charging member and the image carrier may occur. .

Here, the resin film in the present embodiment is sandwiched between the image carrier and the charging unit before use of the process cartridge or the image forming apparatus (for example, during distribution or storage). At this time, the image carrier and the charging unit are separated from each other.
By sandwiching the resin film in the present embodiment having the above-mentioned requirements before use, the image carrier is charged by friction or peeling between the image carrier and the charging unit before use of the process cartridge or the image forming apparatus. Therefore, the occurrence of charging history of the image carrier is suppressed.
That is, according to the process cartridge or the image forming apparatus according to the above-described embodiment, the occurrence of charging history of the image carrier is suppressed, and unevenness of the light sensitivity of the image carrier when used for the first time is suppressed. As a result, in the formed image, image defects (color stripes) due to the light sensitivity unevenness are suppressed.
Here, “image defect is suppressed” means that the image defect has already been suppressed at the first sheet after the start of use, or an image defect has occurred at the first sheet after the start of use, 50 sheets Indicates a state in which image defects are improved by printing within.

Oxygen atom content measured by X-ray electron spectroscopy (XPS) on the surface in contact with the image carrier of the resin film of this embodiment, and oxygen atoms measured by X-ray electron spectroscopy (XPS) inside the surface The difference in the content is 1 atom% or more and 20 atom% or less as described above, and more preferably 5 atom% or more and 15 atom% or less.
If the difference is too small, the effect of suppressing image defects due to vibration is not sufficient. If the difference is too large, image defects after storage are particularly noticeable and are not suppressed even when several tens of sheets are printed.

Further, the wetting tension of the surface of the resin film in contact with the image carrier of the present embodiment is 35 mN / m or more and 55 mN / m or less, more preferably 40 mN / m or more and 55 mN / m or less as described above.
If the wetting tension of the surface in contact with the image carrier is too small, the effect of suppressing image defects due to vibration is not sufficient. If the wetting tension is too large, streak-like image defects occur.

  In addition, as a method of adjusting the oxygen atom content measured by X-ray electron spectroscopy (XPS) of the surface of the resin film in contact with the image carrier and the wetting tension within the above range, for example, the surface in contact with the image carrier Examples thereof include a method of performing a corona discharge treatment, an ultraviolet irradiation treatment, an ozone treatment, a plasma treatment, or the like. Details will be described later.

  Hereinafter, the charging means (hereinafter also referred to as “charging member” or “charging device”), the image carrier, and the resin film in the process cartridge and the image forming apparatus of the present embodiment will be described.

(Charging member)
The charging member in the present embodiment is a member that contacts an image carrier (for example, an electrophotographic photosensitive member) and charges the surface of the image carrier.
The charging member in this embodiment is not particularly limited as long as it is a contact-type charging member used in electrophotography and electrostatic recording processes, but has a shape such as a roll, a brush, a tube, and a blade, and a voltage is applied. In the case of a conductive member that is used, the effect of this embodiment is remarkable.
In this embodiment, in order to obtain a higher effect, the charging member is preferably a roll-shaped charging member (hereinafter also referred to as “charging roll”).

Hereinafter, a charging roll will be described as an example of the charging member.
The configuration of the charging roll is not particularly limited, but at least a conductive elastic layer is provided on the surface of the conductive support, and a resistance layer, a surface layer, etc. are provided on the conductive elastic layer. Other layers may be formed. Moreover, you may use an adhesive agent between layers as needed.
In this embodiment, “conductive” refers to the property of having a volume resistivity of less than 10 ¹³ Ω · cm, and “insulating” refers to the property of having a volume resistivity of 10 ¹³ Ω · cm or more. Point to.

1 and 2 show an example of the layer configuration of the charging roll in the present embodiment.
FIG. 1 is a sectional view of a charging roll in which a conductive elastic layer 32 and a surface layer 33 are sequentially formed on the surface of a conductive support 31. However, the surface layer 33 may be omitted.
FIG. 2 is a sectional view of a charging roll in which a conductive elastic layer 32, a resistance layer 34, and a surface layer 33 are sequentially formed on the surface of a conductive support 31. In addition, you may use an adhesive agent between each layer.

  Hereinafter, the conductive support, the conductive elastic layer, the resistance layer, and the surface layer constituting the charging roll will be described in detail. These constituent members are also used for charging members having shapes other than the charging roll.

  The conductive support functions as an electrode and a support member for the charging roll. For example, a metal or an alloy such as aluminum, copper alloy, or stainless steel; iron plated with chromium, nickel, etc .; conductive resin It is composed of a conductive material such as;

The conductive elastic layer and the resistance layer are formed, for example, by dispersing a conductive agent in a rubber material. Rubber materials include isoprene rubber, chloroprene rubber, epichlorohydrin rubber, butyl rubber, polyurethane, silicone rubber, fluorine rubber, styrene-butadiene rubber, butadiene rubber, nitrile rubber, ethylene propylene rubber, epichlorohydrin-ethylene oxide copolymer rubber, epichlorohydrin-ethylene oxide- Examples include allyl glycidyl ether copolymer rubber, ethylene-propylene-diene terpolymer rubber (EPDM), acrylonitrile-butadiene copolymer rubber (NBR), natural rubber, and blend rubbers thereof. Among these, polyurethane, silicone rubber, EPDM, epichlorohydrin-ethylene oxide copolymer rubber, epichlorohydrin-ethylene oxide-allyl glycidyl ether copolymer rubber, NBR, and blended rubbers thereof are preferably used.
In particular, in the conductive elastic layer, these rubber materials may be foamed or non-foamed.

As the conductive agent dispersed in the rubber material, an electronic conductive agent or an ionic conductive agent is used. Examples of electronic conductive agents include carbon blacks such as ketjen black and acetylene black; pyrolytic carbon, graphite; various conductive metals or alloys such as aluminum, copper, nickel, and stainless steel; tin oxide, indium oxide, titanium oxide And various conductive metal oxides such as tin oxide-antimony oxide solid solution and tin oxide-indium oxide solid solution; Examples of ionic conductive agents include perchlorates and chlorates such as tetraethylammonium and lauryltrimethylammonium; alkali metals such as lithium and magnesium; perchlorates and chlorates of alkaline earth metals ;
These conductive agents may be used alone or in combination of two or more.
The amount of addition is not particularly limited, but in the case of the electronic conductive agent, it is preferably in the range of 1 part by mass to 30 parts by mass with respect to 100 parts by mass of the rubber material. More preferably, it is in the range of less than or equal to parts by mass. On the other hand, in the case of the ionic conductive agent, it is preferably in the range of 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the rubber material, and 0.5 to 3.0 parts by mass. The following range is more preferable.

  When forming the conductive elastic layer, the mixing method and mixing order of each component of the conductive agent, rubber material, and other components (such as a vulcanizing agent and a foaming agent added as necessary) constituting this layer are particularly Although not limited, as a general method, a method of mixing by a Banbury mixer, a kneader, a roll, or the like and molding by extrusion molding, press molding, injection molding, or the like can be given.

The surface layer is configured using a polymer material. The polymer material is not particularly limited, but polyamide, polyurethane, polyvinylidene fluoride, tetrafluoroethylene copolymer, polyester, polyimide, silicone resin, acrylic resin, polyvinyl butyral, ethylenetetrafluoroethylene copolymer, melamine resin , Fluororubber, epoxy resin, polycarbonate, polyvinyl alcohol, cellulose, polyvinylidene chloride, polyvinyl chloride, polyethylene, ethylene vinyl acetate copolymer and the like.
These polymer materials may be used alone or in combination of two or more. The number average molecular weight of the polymer material is preferably in the range of 1,000 to 100,000, and more preferably in the range of 10,000 to 50,000.
The surface layer is preferably constituted by using the conductive agent and various particles used for the conductive elastic layer described above as the conductive agent in addition to the polymer material. Although there is no restriction | limiting in particular in these addition amount, It is preferable that it is the range of 1 to 50 mass parts with respect to 100 mass parts of polymeric materials, and is the range of 5 to 20 mass parts. Is more preferable.

As the particles used for the surface layer, metal oxides such as silicon oxide, aluminum oxide and barium titanate and composite metal oxides, and polymer fine powders such as tetrafluoroethylene and vinylidene fluoride are used alone or in combination. However, the present invention is not limited to these.
When forming the surface layer, a method of forming a coating film on the surface of the conductive elastic layer using a known coating method such as dip coating with a coating solution containing the material constituting the surface layer, and heating and drying the coating film Is used. Alternatively, a surface layer previously formed in a tube shape may be formed by covering the surface of the conductive elastic layer.
The surface layer may be bonded and fixed to the surface of the conductive elastic layer using an adhesive.
In the case of using a tube-shaped surface layer whose inner diameter is slightly smaller than the outer diameter of a roll made of a conductive support and a conductive elastic layer, a fluid such as air is provided on the inner peripheral side of the tube-shaped surface layer. In this state, the surface layer may be fixed to the surface of the conductive elastic layer by inserting a roll on the inner peripheral side of the surface layer and then stopping the injection of fluid.

(Image carrier)
An image carrier used in the image forming apparatus of this embodiment will be described.
As the image carrier, an electrophotographic photosensitive member having a photosensitive layer (for example, a photosensitive layer which is a laminate including a charge generation layer and a charge transport layer) on a conductive substrate is suitable.
3, 4, 5, and 6 are schematic cross-sectional views each showing a preferred embodiment of the electrophotographic photosensitive member in the present embodiment. The electrophotographic photosensitive member 11 is composed of a conductive substrate 12 and a photosensitive layer. 13 is cut along a plane perpendicular to the stacking direction. The electrophotographic photosensitive member 11 shown in FIGS. 3, 4, 5, and 6 is a function-separated type photosensitive member, and a charge generation layer 15 and a charge transport layer 16 are provided in the photosensitive layer 13 provided in each photosensitive member. Are provided separately.

  More specifically, in the electrophotographic photoreceptor 11 shown in FIG. 3, the charge generation layer 15 and the charge transport layer 16 are laminated in this order on the conductive substrate 12, and the photosensitive layer 13 is configured. In the electrophotographic photoreceptor 11 shown in FIG. 5, the undercoat layer 14, the charge generation layer 15, and the charge transport layer 16 are laminated in this order on the conductive substrate 12 to form the photosensitive layer 13. In the electrophotographic photoreceptor 11 shown in FIG. 1, the undercoat layer 14, the charge generation layer 15, the charge transport layer 16 and the protective layer 17 are laminated on the conductive substrate 12 in this order to form the photosensitive layer 13. . In the electrophotographic photoreceptor 11 shown in FIG. 6, the undercoat layer 14, the intermediate layer 18, the charge generation layer 15, and the charge transport layer 16 are laminated in this order on the conductive substrate 12 to form the photosensitive layer 13. ing. In addition, although not described here, the present embodiment is also preferably carried out in a single-layer electrophotographic photosensitive member in which the photosensitive layer is a single layer containing both a charge generation material and a charge transport material. .

Hereinafter, each component of the electrophotographic photoreceptor 11 will be described in detail.
Examples of the conductive substrate 12 include metal substrates such as aluminum, copper, iron, zinc, and nickel; aluminum, copper, gold, silver, platinum, palladium, titanium, nickel-chromium, stainless steel on a substrate such as paper, plastic, and glass. Deposited metal such as steel, copper-indium, etc .; Deposited conductive metal compound such as indium oxide and tin oxide on the substrate; Laminated metal foil on the substrate; Carbon black, Indium oxide, Tin oxide -Antimony oxide powder, metal powder, copper iodide and the like are dispersed in a binder resin and applied to the substrate to conduct a conductive treatment. The shape of the conductive substrate 12 may be any of a drum shape, a sheet shape, and a plate shape.

  Further, when a metal pipe base is used as the conductive base 12, the surface of the pipe base may be a raw pipe, but the surface of the base is roughened by a surface treatment in advance. There may be. Due to such roughening, when a coherent light source such as a laser beam is used as the exposure light source, grain-like density spots due to interference light that can be generated inside the photosensitive member are suppressed. Examples of the surface treatment include mirror cutting, etching, anodizing, rough cutting, centerless grinding, sand blasting, wet honing and the like.

  Materials used for the undercoat layer 14 include zirconium chelate compounds, zirconium alkoxide compounds, zirconium coupling agents and other organic zirconium compounds; titanium chelate compounds, titanium alkoxide compounds, titanate coupling agents and other organic titanium compounds; aluminum chelate compounds Organoaluminum compounds such as aluminum coupling agents; antimony alkoxide compounds; germanium alkoxide compounds; organic indium compounds such as indium alkoxide compounds and indium chelate compounds; organic manganese compounds such as manganese alkoxide compounds and manganese chelate compounds; tin alkoxide compounds and Suzuki Organotin compounds such as rate compounds; Aluminum silicon alkoxide compounds; Aluminum titanium Rukokishido compounds; aluminum zirconium alkoxide compounds include organometallic compounds such as. Among these, an organozirconium compound, an organotitanium compound, and an organoaluminum compound are preferably used because of their low residual potential and good electrophotographic characteristics.

  Further, the undercoat layer 14 may be used by containing a silane coupling agent. Furthermore, polyvinyl alcohol, polyvinyl methyl ether, poly-N-vinylimidazole, polyethylene oxide, ethyl cellulose, methyl cellulose, ethylene-acrylic acid copolymer, polyamide, polyimide, casein, gelatin, polyethylene, polyester, phenol resin, vinyl chloride- A known binder resin such as vinyl acetate copolymer, epoxy resin, polyvinyl pyrrolidone, polyvinyl pyridine, polyurethane, polyglutamic acid, polyacrylic acid may be used. These mixing ratios are set as necessary.

  In the present embodiment, the undercoat layer 14 may contain metal oxide particles. The metal oxide particles are selected from known metal oxides as long as the desired electrophotographic photosensitive member characteristics can be obtained. One or more metal oxides selected from tin oxide, titanium oxide, and zinc oxide are used. Product particles are preferably used. In addition, these metal oxide particles are more preferably coated with at least one coupling agent, and the silane coupling agent is more preferable as the coupling agent.

  Further, an electron transporting pigment may be mixed / dispersed in the undercoat layer 14. Examples of electron transport pigments include organic pigments such as perylene pigments, bisbenzimidazole perylene pigments, polycyclic quinone pigments, indigo pigments, and quinacridone pigments, and electron-withdrawing pigments such as cyano groups, nitro groups, nitroso groups, and halogen atoms. Examples thereof include organic pigments such as bisazo pigments and phthalocyanine pigments having a substituent, and inorganic pigments such as zinc oxide and titanium oxide. Among these pigments, perylene pigments, bisbenzimidazole perylene pigments and polycyclic quinone pigments are preferably used because of their high electron mobility. If the amount of the electron transporting pigment is too large, the strength of the undercoat layer is lowered and a coating film defect is caused.

  The undercoat layer 14 may be formed by including in the layer together with metal oxide particles to which an acceptor compound is attached, or a metal oxide. As the acceptor compound, any compound can be used as long as the desired characteristics can be obtained. In particular, a compound having a quinone group is preferably used. Furthermore, an acceptor compound having an anthraquinone structure is preferably used. Examples of the compound having an anthraquinone structure include hydroxyanthraquinone compounds, aminoanthraquinone compounds, aminohydroxyanthraquinone compounds and the like, in addition to anthraquinone, and any of them is preferably used. More specifically, anthraquinone, alizarin, quinizarin, anthralphine, pullpurin and the like are particularly preferably used.

The adhering amount of these acceptor compounds is set in a range where desired characteristics can be obtained, but is preferably 0.01% by mass or more and 20% by mass or less based on the metal oxide. More preferably, it is 0.05 mass% or more and 10 mass% or less with respect to a metal oxide.
As a method for attaching the acceptor compound to the metal oxide particles, the acceptor compound dissolved in an organic solvent is dropped and sprayed with dry air or nitrogen gas while stirring the metal oxide particles with a mixer having a large shearing force. Is attached by. The addition or spraying is preferably performed at a temperature below the boiling point of the solvent. After addition or spraying, drying may be performed at a temperature higher than the boiling point of the solvent. Further, the metal oxide particles are stirred in a solvent, dispersed using ultrasonic waves, a sand mill, an attritor, a ball mill, etc., and an organic solvent solution of an acceptor compound is added and stirred or dispersed below the boiling point of the organic solvent. Thereafter, the solvent may be removed. Moreover, the solvent removal method is distilled off by filtration, distillation, or heat drying.

The metal oxide particles preferably have a powder resistance of 10 ² Ω · cm to 10 ¹¹ Ω · cm.

The undercoat layer 14 is formed by applying a coating solution obtained by mixing / dispersing the above materials in an organic solvent onto the substrate 12 and removing the solvent by drying.
Examples of the mixing / dispersing method in preparing the coating solution for the undercoat layer include a ball mill, a roll mill, a sand mill, an attritor, and an ultrasonic wave. Any organic solvent may be used as long as it does not cause gelation or aggregation when an organometallic compound or resin is dissolved and an electron transporting pigment is mixed / dispersed. Specifically, methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, methylene chloride, chloroform , Chlorobenzene, toluene and the like, and these are used singly or in combination of two or more. The coating solution is dried at a temperature at which the solvent can be evaporated to form a film. The thickness of the undercoat layer 14 thus obtained is preferably 0.1 μm or more and 10 μm or less, and more preferably 0.5 μm or more and 5.0 μm or less when the metal oxide particles are not contained. More preferred. Moreover, when it contains a metal oxide particle, it is preferably 15 μm or more, and more preferably 15 μm or more and 50 μm or less.

  Examples of the material used for the intermediate layer 18 include organometallic compounds used for the undercoat layer 14. Among these, an organic zirconium compound, an organic titanium compound, and an organic aluminum compound are preferably used.

  Further, as described in the undercoat layer 14, the intermediate layer 18 may contain a silane coupling agent. Furthermore, polyvinyl alcohol, polyvinyl methyl ether, poly-N-vinylimidazole, polyethylene oxide, ethyl cellulose, methyl cellulose, ethylene-acrylic acid copolymer, polyamide, polyimide, casein, gelatin, polyethylene, polyester, phenol resin, vinyl chloride- A known binder resin such as vinyl acetate copolymer, epoxy resin, polyvinyl pyrrolidone, polyvinyl pyridine, polyurethane, polyglutamic acid, polyacrylic acid may be used. These mixing ratios are set as necessary.

Further, as described in the undercoat layer 14, an electron transporting pigment may be mixed / dispersed in the intermediate layer 18.
Examples of electron transport pigments include organic pigments such as perylene pigments, bisbenzimidazole perylene pigments, polycyclic quinone pigments, indigo pigments, and quinacridone pigments, and electron-withdrawing pigments such as cyano groups, nitro groups, nitroso groups, and halogen atoms. Examples thereof include organic pigments such as bisazo pigments and phthalocyanine pigments having a substituent, and inorganic pigments such as zinc oxide and titanium oxide. Among these pigments, perylene pigments, bisbenzimidazole perylene pigments and polycyclic quinone pigments are preferably used. The electron transport pigment is preferably used in an amount of 95% by mass or less, more preferably 90% by mass or less.

As described in the undercoat layer 14, the intermediate layer 18 is formed by applying a coating solution obtained by mixing / dispersing the above material in an organic solvent on the substrate 12 and removing the solvent by drying.
Examples of the mixing / dispersing method in preparing the coating solution for the undercoat layer include a ball mill, a roll mill, a sand mill, an attritor, and an ultrasonic wave.
Any organic solvent may be used as long as it does not cause gelation or aggregation when an organometallic compound or resin is dissolved and an electron transporting pigment is mixed / dispersed. Specifically, methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, methylene chloride, chloroform , Chlorobenzene, toluene and the like. These are used individually by 1 type or in mixture of 2 or more types.
The coating solution is dried at a temperature at which the solvent can be evaporated to form a film. The thickness of the intermediate layer 18 thus obtained is preferably from 0.1 μm to 10 μm, and more preferably from 0.5 μm to 5 μm.

  The charge generation layer 15 is made of a known charge generation material dispersed and held in a known binder resin. As this charge generating substance, phthalocyanine is preferably used. Among these phthalocyanines, it is preferable to contain a hydroxygallium phthalocyanine pigment. Any hydroxygallium phthalocyanine used in the present embodiment may be used. In particular, diffraction peaks are generated at Bragg angles (2θ ± 0.2 °) of 7.5 ° and 28.3 ° with respect to CuKα characteristic X-rays. What has is used preferably.

The binder resin for dispersing and holding the charge generating substance is selected from a wide range of insulating resins. Preferred binder resins include polyvinyl acetal resin, polyarylate resin, polycarbonate resin, polyester resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyamide resin, acrylic resin, polyacrylamide resin, polyvinyl pyridine resin, cellulose resin, Examples thereof include insulating resins such as urethane resin, epoxy resin, casein, polyvinyl alcohol resin, and polyvinylpyrrolidone resin, and organic photoconductive polymers such as poly-N-vinyl carbazole, polyvinyl anthracene, polyvinyl pyrene, and polysilane. Among these, polyvinyl acetal resin and vinyl chloride-vinyl acetate copolymer are preferably used.
These binder resins are used alone or in combination of two or more. The blending ratio (mass ratio) of the charge generation material and the binder resin is preferably in the range of 1:10 to 10: 1, and more preferably in the range of 3: 7 to 8: 2.

When the charge generation layer 15 is formed, a coating solution in which the hydroxygallium phthalocyanine pigment is dispersed in a solution in which a binder resin is dissolved in an organic solvent is used.
As an organic solvent for the coating solution for the charge generation layer, a solvent capable of dissolving the binder resin, for example, alcohol, aromatic, halogenated hydrocarbon, ketone, ketone alcohol, ether, ester, and the like Is used. More specifically, methanol, ethanol, n-propanol, iso-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, n-butyl acetate, Examples include dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, toluene, xylene, dimethylformamide, dimethylacetamide, water and the like. These solvents are used alone or in combination of two or more. Examples of a method for dispersing the hydroxygallium phthalocyanine pigment in the binder resin liquid include a ball mill, a roll mill, a sand mill, an attritor, and an ultrasonic wave.

In the hydroxygallium phthalocyanine dispersion of this embodiment, the surface treatment may be performed on the hydroxygallium phthalocyanine pigment. As the surface treatment agent, a silane coupling agent or the like is used, but is not limited thereto.
In addition to the silane coupling agent, an organic zirconium compound, an organic titanium compound, or an organic aluminum compound may be used.

  The charge generation layer coating solution may be subjected to a centrifugal separation treatment after dispersion.

  The charge generation layer 15 is applied by applying the coating solution for charge generation layer described above by blade coating, wire bar coating, spray coating, dip coating, bead coating, air knife coating, curtain coating, or the like. It is obtained by doing.

  The thickness of the charge generation layer 15 thus obtained is preferably 0.05 μm or more and 5 μm or less, and more preferably 0.1 μm or more and 1 μm or less.

  The charge transport layer 16 includes a charge transport material and a binder resin. Specific examples of such charge transport materials include oxadiazole derivatives such as 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadiazole, 1,3,5-triphenylpyrazoline. 1- [pyridyl- (2)]-3- (p-diethylaminostyryl) -5- (p-diethylaminostyryl) pyrazoline and other pyrazoline derivatives, triphenylamine, tri (p-methyl) phenylamine, N, N Aromatic tertiary such as' -bis (3,4-dimethylphenyl) biphenyl-4-amine, dibenzylaniline, 9,9-dimethyl-N, N'-di (p-tolyl) fluoren-2-amine Aromatic tertiary dia such as amino compounds, N, N′-diphenyl N, N′-bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine Compounds, 1,2,4-triazine derivatives such as 3- (4′-dimethylaminophenyl) -5,6-di- (4′-methoxyphenyl) -1,2,4-triazine, 4-diethylaminobenzaldehyde Hydrazone derivatives such as -1,1-diphenylhydrazone, 4-diphenylaminobenzaldehyde-1,1-diphenylhydrazone, [p- (diethylamino) phenyl]-(1-naphthyl) -phenylhydrazone, 2-phenyl-4-styryl Quinazoline derivatives such as quinazoline, benzofuran derivatives such as 6-hydroxy-2,3-di (p-methoxyphenyl) benzofuran, and α-stilbene such as p- (2,2-diphenylvinyl) -N, N′-diphenylaniline Derivatives, enamine derivatives, carbazole derivatives such as N-ethylcarbazole And hole transport materials such as poly-N-vinylcarbazole and derivatives thereof. In addition, quinone compounds such as chloranil, bromoanil, anthraquinone, tetracyanoquinodimethane compounds, fluorenone compounds such as 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2 -(4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, 2,5-bis (4-naphthyl) -1,3,4-oxadiazole, 2 Oxadiazole compounds such as 1,5-bis (4-diethylaminophenyl) -1,3,4-oxadiazole, xanthone compounds, thiophene compounds, 3,3 ′, 5,5′-tetra-t-butyl Electron transport materials such as diphenoquinone compounds such as diphenoquinone may be used. Furthermore, you may use the polymer which has the group which consists of the said compound in a principal chain or a side chain. These charge transport materials are used singly or in combination of two or more.

The binder resin for the charge transport layer 16 is preferably a resin that can form an electrically insulating film. Examples of this resin include polycarbonate resin, polyarylate resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer, and vinylidene chloride. Acrylonitrile copolymer, vinyl chloride-vinyl acetate copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly-N-carbazole , Polyvinyl butyral, polyvinyl formal, polysulfone, casein, gelatin, polyvinyl alcohol, ethyl cellulose, phenol resin, polyamide, carboxy-methyl cellulose, vinyl chloride Den polymer waxes, polyurethanes, and the like. These binder resins are used singly or in combination of two or more.
The compounding ratio (mass ratio) of the binder resin and the charge transport material is not particularly limited, but it is preferable to pay attention to a decrease in electrical characteristics and a decrease in film strength.

The charge transport layer 16 is formed by applying a charge transport layer coating liquid containing the above material onto the charge generation layer 15 and drying it. The solvent used in the coating solution is selected from known organic solvents as long as the desired electrophotographic photoreceptor characteristics can be obtained, but dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, toluene and the like are preferable. used. Moreover, these are used individually by 1 type or in mixture of 2 or more types. The lower limit of the thickness of the charge transport layer 16 is preferably 15 μm or more, more preferably 20 μm or more, and more preferably 30 μm or more, from the viewpoint of securing the chargeability and maintainability by reducing the film thickness due to wear. Particularly preferred. As the thickness of the charge transport layer 16 increases, image defects due to vibration tend to occur more strongly, so that the effect of this embodiment is more effectively achieved.
The upper limit of the thickness of the charge transport layer 16 is preferably 60 μm or less and more preferably 50 μm or less from the viewpoint of resolution.

  In the charge transport layer 16, additives such as an antioxidant and a light stabilizer may be added to the photosensitive layer.

Examples of the antioxidant include hindered phenols, hindered amines, paraphenylenediamines, arylalkanes, hydroquinones, spirochromans, spiroidanones and their derivatives, organic sulfur compounds, and organic phosphorus compounds.
Examples of the light stabilizer include benzophenone, benzotriazole, dithiocarbamate, and tetramethylpiperidine derivatives.

Other compounds include 2,4-di-t-butylphenyl-3 ′, 5′-di-t-butyl-4′-hydroxybenzoate, nickel dibutyl-dithiocarbamate, and the like.
Moreover, you may contain an at least 1 sort (s) of electron-accepting substance. Examples of the electron acceptor include succinic anhydride, maleic anhydride, dibromomaleic anhydride, phthalic anhydride, tetrabromophthalic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m-dinitrobenzene, Examples include chloranilquinone, dinitroanthraquinone, trinitrofluorenone, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, and phthalic acid. Among these, fluorenone compounds, quinone compounds and, Cl-, CN-, NO 2 _- benzene derivatives having an electron attractive substituent, and the like are particularly preferable.

Further, a solid lubricant or a metal oxide may be dispersed in the charge transport layer 16. Examples of solid lubricants include fluorine-containing resin particles (ethylene tetrafluoride, ethylene trifluoride chloride, ethylene tetrafluoride hexafluoropropylene resin, vinyl fluoride resin, vinylidene fluoride resin, ethylene difluoride dichloride and those And the like, and silicon-containing resin particles. Examples of the metal oxide include silica, alumina, titanium oxide, and tin oxide. Further, since the fluorine-containing resin particles are hardly dispersed particles, a fluorine-containing polymer-based dispersion aid may be used. As a method for dispersing the solid lubricant and the metal oxide, for example, a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a colloid mill, a paint shaker, a homogenizer, a high-pressure treatment type homogenizer, or the like is used. In this dispersion, it is effective to make the dispersed particles 1.0 μm or less, preferably 0.5 μm or less.
Silicone oil may be added as a leveling agent.

  As shown in FIG. 5, a protective layer 17 may be formed on the electrophotographic photosensitive member of the present embodiment as necessary. As the surface protective layer 17, any known one can be used. As the surface protective layer 17, for example, a cured film formed containing a compound represented by the following general formula (I) is preferable.

F- [DA] _b (I)

In general formula (I), F represents an organic group derived from a photofunctional compound, D represents a divalent group, and A represents a hydrolysis represented by —SiR ¹ _3-a (OR ² ) _a. Represents a substituted silicon group having a functional group, and b represents an integer of 1 or more and 4 or less. Here, R ¹ represents hydrogen, an alkyl group, or a substituted or unsubstituted aryl group, and R ² represents hydrogen, an alkyl group, or a trialkylsilyl group. a represents an integer of 1 to 3.

A substituted silicon group having a hydrolyzable group represented by A in general formula (I), that is, -SiR ¹ _3-a (OR ² ) _a is a three-dimensional Si-O-Si bond ( It plays a role in forming an inorganic glassy network.
In general formula (I), F is an organic group having photoelectric characteristics, more specifically, photocarrier transport characteristics, and the structure of a photofunctional compound conventionally known as a charge transport material is used as it is. . Specific examples of the organic group represented by F include triarylamine compounds, benzidine compounds, arylalkane compounds, aryl-substituted ethylene compounds, stilbene compounds, anthracene compounds, hydrazone compounds, and the like. Examples include a compound skeleton having a hole transporting property, and a compound skeleton having an electron transporting property such as a quinone compound, a fluorenone compound, a xanthone compound, a benzophenone compound, a cyanovinyl compound, and an ethylene compound.

  Preferable examples of the organic group represented by F include groups represented by the following general formula (II). When F is a group represented by the general formula (II), particularly excellent photoelectric characteristics and mechanical characteristics are exhibited.

In general formula (II), Ar ¹ , Ar ² , Ar ³ , and Ar ⁴ each independently represent a substituted or unsubstituted aryl group. Ar ⁵ represents a substituted or unsubstituted aryl group or an arylene group. B of Ar ¹ , Ar ² , Ar ³ , and Ar ⁴ is bonded to a group represented by —D—SiR ¹ _3-a (OR ² ) _a . k represents 0 or 1; b represents an integer of 1 or more and 4 or less.
Ar ¹ , Ar ² , Ar ³ , and Ar ^{4 in the} general formula (II) are preferably any of the following formulas (II-1) to (II-7).

_{-Ar-Z 's -Ar-X} m (II-7)

In the formula, R ⁶ is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 4 carbon atoms, or a phenyl group substituted with an alkoxy group having 1 to 4 carbon atoms, or unsubstituted phenyl. Represents a group selected from the group consisting of an aralkyl group having 7 to 10 carbon atoms, R ⁷ , R ⁸ and R ⁹ are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, and 1 or more carbon atoms One type selected from the group consisting of an alkoxy group having 4 or less carbon atoms, a phenyl group substituted with an alkoxy group having 1 to 4 carbon atoms, or an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, and a halogen atom the stands, Ar represents a substituted or unsubstituted arylene group, X represents a in the general formula _{^{(I) -D-SiR 1 3}} -a (oR 2) a, m and s each represents 0 or 1 And, t is 1 to 3 each represent an integer. ]
Here, as Ar in Formula (II-7), what is represented by following formula (II-8) or (II-9) is preferable.

In the formula, R ¹⁰ and R ¹¹ are each a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a phenyl group substituted with an alkoxy group having 1 to 4 carbon atoms, Alternatively, it represents one type selected from the group consisting of an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, and a halogen atom, and t represents an integer of 1 to 3.
Moreover, as Z 'in Formula (II-7), what is represented by either of following formula (II-10) to (II-17) is preferable.

_{- (CH 2) q - (} II-10)
_{- (CH 2 CH 2 O)} r - (II-11)

In the formula, each of R ¹² and R ¹³ is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, or a phenyl group substituted with an alkoxy group having 1 to 4 carbon atoms, Or an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, or one selected from the group consisting of halogen atoms, W represents a divalent group, and q and r are each an integer of 1 to 10 And t represents an integer of 1 or more and 3 or less, respectively.
W in the formulas (II-16) and (II-17) is preferably any one of divalent groups represented by the following (II-18) to (II-26). .

—CH ₂ — (II-18)
_{-C (CH 3) 2 - (} II-19)
-O- (II-20)
-S- (II-21)
_{-C (CF 3) 2 - (} II-22)
—Si (CH ₃ ) ₂ — (II-23)

In the formula, u represents an integer of 0 or more and 3 or less.
In general formula (II), Ar ₅ is an aryl group exemplified in the description of Ar ¹ , Ar ² , Ar ³ , and Ar ⁴ when k is 0, and such aryl when k is 1 An arylene group obtained by removing a hydrogen atom from a group.

In the general formula (I), the divalent group represented by D plays a role of linking F that imparts photoelectric characteristics and A that is directly bonded to the three-dimensional inorganic glassy network. Examples of the divalent group represented by D, and _{specifically, -C n H 2n -, -} C n H 2n-2 -, - C n H 2n-4 - 2 divalent hydrocarbon group represented by (n represents an integer of 1 to 15), - COO -, - S -, - O -, - CH 2 -C 6 H 4 -, - n = CH -, - C 6 H 4 -C 6 H _4- , and combinations thereof, and those having a substituent introduced.

In general formula (I), b is preferably 2 or more. When b is 2 or more, the photofunctional organosilicon compound represented by general formula (I) has two or more Si atoms. Become.
The compound represented by general formula (I) may be used individually by 1 type, and may be used together 2 or more types.

Moreover, you may use together the compound represented by the following general formula (III) with the compound represented by general formula (I).
B-A _n (III)
In General Formula (III), A represents a substituted silicon group having a hydrolyzable group represented by —SiR ¹ _3-a (OR ² ) _a . Here ^is the same as R ^{1, R} 2, a is ^R 1 in the general formula ^{(I), R 2, a} . B is composed of at least one group selected from a divalent or higher valent hydrocarbon group, a divalent or higher valent phenyl group, and —NH—, which may contain a branch, or a combination thereof. n represents an integer of 2 or more.

The compound represented by the general formula (III) is a compound having a substituted silicon group having a hydrolyzable group represented by A, that is, -SiR ¹ _3-a (OR ² ) _a . The compound represented by the general formula (III) forms a Si—O—Si bond by the reaction with the compound represented by the general formula (I) or the reaction between the compounds represented by the general formula (III). Thus, a three-dimensional crosslinked cured film is provided. Preferred examples of the compound represented by the general formula (III) are shown below (Exemplary Compounds III-1 to III-19).

  In addition to the compound represented by the general formula (I), another compound that undergoes a crosslinking reaction may be used in combination. As such a compound, for example, various silane coupling agents and commercially available silicone hard coat agents are used.

  As silane coupling agents, vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxy Silane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, tetramethoxysilane, methyltrimethoxysilane, Examples include dimethyldimethoxysilane.

  As a commercially available hard coat agent, KP-85, CR-39, X-12-2208, X-40-9740, X-4101007, KNS-5300, X-40-2239 (manufactured by Shin-Etsu Silicone), AY42-440, AY42-441, AY49-208 (manufactured by Toray Dow Corning) and the like.

A fluorine-containing compound may be added to the protective layer 17.
As the fluorine-containing compound, a fluorine atom-containing polymer such as polytetrafluoroethylene may be added as it is, or particles of these polymers may be added. Further, in the case of a cured film formed of the compound represented by the general formula (I), it is desirable to add a compound that reacts with alkoxysilane as the fluorine-containing compound to constitute a part of the crosslinked film. Examples of the fluorine-containing compound include (tridecafluoro-1,1,2,2-tetrahydrooctyl) triethoxysilane, (3,3,3-trifluoropropyl) trimethoxysilane, and 3- (heptafluoroisopropoxy). ) Propyltriethoxysilane, 1H, 1H, 2H, 2H-perfluoroalkyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane Etc.

  The content of the fluorine-containing compound is preferably 20% by mass or less based on the total amount of the protective layer 17.

  The protective layer 17 containing the compound may contain an antioxidant. As the antioxidant, a hindered phenol antioxidant or a hindered amine antioxidant is desirable, an organic sulfur antioxidant, a phosphite antioxidant, a dithiocarbamate antioxidant, a thiourea antioxidant, A known antioxidant such as a benzimidazole antioxidant may be used. As content of antioxidant, 15 mass% or less is preferable on the basis of the protective layer 17 whole quantity, and 10 mass% or less is more preferable.

Moreover, you may add the other additive used for well-known coating-film formation to the protective layer 17, For example, well-known things, such as a leveling agent, a ultraviolet absorber, a light stabilizer, and surfactant, are used. .
The protective layer 17 is formed by applying a coating solution containing the above compound onto the charge transport layer 16 and subjecting it to a heat treatment. Thereby, the compound etc. which are represented with general formula (I) raise | generate a crosslinking hardening reaction three-dimensionally, and a cured film is formed. The temperature of the heat treatment is not particularly limited as long as it does not affect the lower layer, but is preferably room temperature (22 ° C.) or higher and 200 ° C. or lower, more preferably 100 ° C. or higher and 160 ° C. or lower.

The crosslinking curing reaction may be performed without a catalyst, or an appropriate catalyst may be used. Catalysts include acid catalysts such as hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, acetic acid, trifluoroacetic acid, bases such as ammonia and triethylamine, organotin compounds such as dibutyltin diacetate, dibutyltin dioctoate, stannous oxalate, Examples thereof include organic titanium compounds such as tetra-n-butyl titanate and tetraisopropyl titanate, iron salts of organic carboxylic acids, manganese salts, cobalt salts, zinc salts, zirconium salts, and aluminum chelate compounds.
Moreover, in order to make easy application | coating of the coating liquid for protective layers, you may add and use a solvent as needed. Specifically, water, methanol, ethanol, n-propanol, i-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, Examples include methylene chloride, chloroform, dimethyl ether, and dibutyl ether. These solvents may be used alone or in a combination of two or more.

Examples of the coating method include a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, and a curtain coating method.
The film thickness of the protective layer 17 thus formed is preferably 0.5 μm or more and 20 μm or less, more preferably 2 μm or more and 10 μm or less.
As the protective layer, those described in, for example, JP-A-2009-229549, JP-A-2000-206715, and the like can be used in addition to those described above.

[Resin film]
The resin film in the present embodiment is sandwiched between the image carrier and the charging device, and the oxygen atom content measured by X-ray electron spectroscopy (XPS) of the surface in contact with the image carrier The difference in oxygen atom content measured by X-ray electron spectroscopy (XPS) on the inner side of the surface is 1 atom% or more and 20 atom% or less, and the wetting tension of the surface in contact with the image carrier is 35 mN / m or more. It is a resin film which is 55 mN / m or less.
The resin film in the present embodiment is sandwiched between the image holding member and the charging unit before use of the process cartridge or the image forming apparatus (for example, during distribution or storage). It is separated from between the image carrier and the charging means.
As a result, charging of the image carrier due to friction or peeling between the image carrier and the charging unit before use of the process cartridge or the image forming apparatus is suppressed, so that occurrence of charging history of the image carrier is suppressed. .

Hereinafter, an example of the resin film in the process cartridge or the image forming apparatus of the present embodiment will be described with reference to FIGS. 7 and 8, but the present embodiment is not limited to this.
FIG. 7 is a schematic cross-sectional view showing an example of a resin film in the process cartridge or the image forming apparatus of the present embodiment.
FIG. 8 is a schematic cross-sectional view illustrating an example of a resin film, an image carrier, and a charging unit in the process cartridge or the image forming apparatus of the present embodiment.
As shown in FIG. 7, the resin film 40 has an oxygen atom content measured by X-ray electron spectroscopy (XPS) on at least one surface (surface 42 in contact with the image carrier), and X inside the surface. The resin film has a difference in oxygen atom content measured by line electron spectroscopy (XPS) of 1 atom% to 20 atom% and a wetting tension of 35 mN / m to 55 mN / m.
Further, as shown in FIG. 8, the resin film 40 is sandwiched between the image carrier 58 and the charging means 56 so as to be separated. At this time, the oxygen atom content measured by X-ray electron spectroscopy (XPS) of the surface 42 in contact with the image carrier 58 and the oxygen atom content measured by X-ray electron spectroscopy (XPS) inside the surface 42 The surface 42 having a difference in amount between 1 atom% and 20 atom% is sandwiched between the image carrier 58 side.

-Difference in oxygen atom content-
Oxygen atom content measured by X-ray electron spectroscopy (XPS) on the surface 42 of the resin film 40 in contact with the image carrier of the present embodiment, and measured by X-ray electron spectroscopy (XPS) inside the surface 42 The difference in oxygen atom content is not less than 1 atom% and not more than 20 atom%, and more preferably not less than 5 atom% and not more than 15 atom%.
If the difference is too small, the effect of suppressing image defects due to vibration is not sufficient. If the difference is too large, image defects after storage are particularly noticeable and are not suppressed even when several tens of sheets are printed.

  The oxygen atom content measured by X-ray electron spectroscopy (XPS) in the present embodiment is measured under the conditions of MgKα (200 W) as an X-ray source using an XPS analyzer (JPS9010 manufactured by JEOL Ltd.). In addition, it refers to a value obtained by correcting the O1s spectral area intensity of oxygen atoms by a relative sensitivity factor specific to the device (photoionization cross-section taking into account electron escape depth and device function) and percentageing. The oxygen atom content measured by X-ray electron spectroscopy (XPS) on the inner side of the surface 42 is measured by the method described above after etching the surface 42 side of the resin film 40 in contact with the image carrier by 1 μm. .

The surface 42 of the resin film 40 that is in contact with the image carrier is the oxygen atom content measured by X-ray electron spectroscopy (XPS) and the oxygen measured by X-ray electron spectroscopy (XPS) inside the surface 42. As a method of adjusting the difference in atomic content to 1 atom% or more and 20 atom% or less and adjusting the wetting tension to 35 mN / m or more and 55 mN / m or less, for example, the surface 42 in contact with the image carrier is subjected to corona discharge treatment, ultraviolet irradiation. Examples of the method include performing treatment, ozone treatment, or plasma treatment.
The ozone treatment is performed by exposing a polymer material (resin film) to ozone. The exposure method is performed by a method of holding in an atmosphere in which ozone exists for a predetermined time, a method of exposing in an ozone stream for a predetermined time, or the like.
In the plasma treatment, the resin film is exposed to a plasma generated by glow discharge in a gas containing argon, neon, helium, nitrogen, nitrogen dioxide, oxygen, air, or the like at a low pressure or atmospheric pressure, and then contains oxygen such as air. In this method, oxygen is introduced into the surface of the material by exposure to gas.
In the corona discharge treatment, a corona discharge is generated by applying an alternating high voltage between a grounded metal roll and a knife-like, saw-like, or wire-like electrode placed at a predetermined interval. This is a method of passing a polymer material (resin film) to be processed between the electrode and the roll during discharge.

Various conditions of the corona discharge treatment, ultraviolet irradiation treatment, ozone treatment, and plasma treatment are determined by the output and passage time, but are not particularly limited. Specifically, it is more desirable to carry out under the following conditions.
In the case of corona discharge treatment, it is desirable that the discharge power per treatment area per minute multiplied by the length (m) of the discharge electrode and the treatment speed (m / min) of the resin film is 15 W or more.

-Oxygen atom content of the surface 42 in contact with the image carrier-
The oxygen atom content measured by X-ray electron spectroscopy (XPS) of the surface 42 of the resin film 40 in contact with the image carrier of the present embodiment is preferably 1 atom% or more and 50 atom% or less, more preferably 1 atom%. It is 20 atom% or less.
If the oxygen atom content measured by X-ray electron spectroscopy (XPS) on the surface 42 in contact with the image carrier is too small, the effect of suppressing image defects due to vibration is not sufficient. In addition, if the oxygen atom content measured by X-ray electron spectroscopy (XPS) on the surface 42 in contact with the image carrier is too large, image defects after storage are particularly noticeable and are not suppressed even when several tens of sheets are printed.

−wetting tension−
The wetting tension of the surface 42 in contact with the image carrier of the resin film 40 of the present embodiment is 35 mN / m or more and 55 mN / m or less, more preferably 45 mN / m or more and 55 mN / m or less.
If the wetting tension of the surface 42 in contact with the electrophotographic photosensitive member is too small, the effect of suppressing image defects due to vibration is not sufficient. If the wetting tension is too large, streak-like image defects occur.

  The wetting tension in this embodiment is measured by the method defined in JIS K6768.

  In addition, as a method of adjusting the wetting tension of the surface 42 of the resin film 40 in contact with the image carrier to the above range, the above-described surface 42 in contact with the image carrier is subjected to corona discharge treatment, ultraviolet irradiation treatment, ozone treatment, Or the method of performing a plasma processing is mentioned.

−Material−
The material of the resin film in the present embodiment is not particularly limited, and examples thereof include those mainly composed of polyester resin such as polyolefin, vinyl chloride, and PET resin, polyamide resin, and the like. Of these, polyolefins are particularly desirable. Specifically, homopolymers of α-olefins such as polyethylene and polypropylene; copolymers of the above α-olefins such as ethylene propylene copolymers are preferably used.
The “main component” means that it accounts for 80% by mass or more.
Further, the resin film 40 in the present embodiment may be a laminated film formed by laminating a plurality of layers, and in that case, at least the material in the surface 42 in contact with the image carrier is the resin listed above. Is desirable.

  The thickness of the resin film in the present embodiment is not particularly limited, but is preferably 5 μm or more and 500 μm or less, and more preferably 10 μm or more and 200 μm or less.

Next, an example of the configuration of the process cartridge according to the present embodiment will be described.
A process cartridge according to an example of the present embodiment is detachable from an image forming apparatus (that is, detachable from the image forming apparatus), and an image carrier (for example, an electrophotographic photosensitive member). And a charging member in contact with the image carrier, and at least a surface in contact with the image carrier is measured by X-ray electron spectroscopy (XPS) between the image carrier and the charging member. The difference between the oxygen atom content and the oxygen atom content measured by X-ray electron spectroscopy (XPS) inside the surface is 1 atom% or more and 20 atom% or less, and the wetting tension of the surface in contact with the image carrier is The resin film which is 35 mN / m or more and 55 mN / m or less should just interpose, and structures other than these are not specifically limited.
More specifically, the process cartridge according to the present embodiment includes an image carrier, a charging member, and a surface (XPS) of a surface in contact with the image carrier that is interposed between the image carrier and the charging member. And the difference between the oxygen atom content measured by X-ray electron spectroscopy (XPS) on the inner side from the surface is 1 atom% or more and 20 atom% or less, and the surface in contact with the image carrier In addition to the resin film having a wetting tension of 35 mN / m or more and 55 mN / m or less, it is a preferable embodiment that a developing device and a cleaning device for an image carrier are combined and integrated by an attachment member. The case is preferably provided with an opening for exposure.

  FIG. 9 is a cross-sectional view schematically showing a preferred embodiment of the process cartridge of the present embodiment. In addition to the electrophotographic photosensitive member 207, the process cartridge 300 includes a charging device 208, a developing device 211, a cleaning device (cleaning means) 213, an opening 218 for exposure, and an opening 217 for static elimination exposure. Are combined and integrated with each other. The electrophotographic photoreceptor 207 preferably has a photosensitive layer containing hydroxygallium phthalocyanine. The developing device 211 supplies toner to the electrophotographic photosensitive member 207.

Further, in the process cartridge 300, the oxygen atom content measured by (XPS) of the surface in contact with the electrophotographic photosensitive member 207 between the electrophotographic photosensitive member 207 and the charging device 208, and X on the inner side of the surface. Resin film in which the difference in oxygen atom content measured by line electron spectroscopy (XPS) is 1 atom% or more and 20 atom% or less, and the wetting tension of the surface in contact with the electrophotographic photosensitive member 207 is 35 mN / m or more and 55 mN / m or less. 240 is sandwiched in such a way that it can be detached. The resin film 240 suppresses friction and peeling between the electrophotographic photosensitive member 207 and the charging device 208 before using the process cartridge 300, and suppresses the occurrence of charging history of the electrophotographic photosensitive member 207.
The resin film 240 is removed when the process cartridge 300 is used.
However, when the process cartridge 300 is not used (during storage or the like), the resin film 240 is again between the electrophotographic photosensitive member 207 and the charging device 208 by (XPS) on the surface in contact with the electrophotographic photosensitive member 207. The difference between the measured oxygen atom content and the oxygen atom content measured by X-ray electron spectroscopy (XPS) inside the surface is 1 atom% or more and 20 atom% or less, and the surface in contact with the electrophotographic photosensitive member 207 You may insert in the direction used as the resin film whose wet tension is 35 mN / m or more and 55 mN / m or less.

  The process cartridge 300 is an image including a transfer device 212, a fixing device 215 that transfers a toner image formed by the developing device 211 to a transfer target (image output medium) 500, and other components not shown. The image forming apparatus can be attached to and detached from the forming apparatus main body, and constitutes the image forming apparatus together with the image forming apparatus main body.

  Each member (developing device 211, cleaning device 213, etc.) included in the process cartridge 300 will be described in detail in the description of the image forming apparatus 200 described later.

Next, the image forming apparatus of this embodiment will be described.
The image forming apparatus of the present embodiment includes an image carrier (for example, an electrophotographic photosensitive member) and a charging member in contact with the image carrier, and at least between the image carrier and the charging member. The difference between the oxygen atom content measured by (XPS) on the surface in contact with the image carrier and the oxygen atom content measured by X-ray electron spectroscopy (XPS) inside the surface is 1 atom% or more and 20 atom% or less. The resin film having a wetting tension of 35 mN / m or more and 55 mN / m or less on the surface in contact with the image carrier may be interposed, and the configuration other than these is not particularly limited.
In addition to the above configuration, the image forming apparatus according to the present embodiment further includes a latent image forming unit that forms a latent image on the surface of the charged image carrier, and a latent image formed on the surface of the image carrier. More preferably, the image forming apparatus includes a developing unit that forms a toner image by developing the toner image, and a transfer unit that transfers the toner image formed on the surface of the image carrier to a recording medium.
Note that the image forming apparatus of the present embodiment may be one in which the process cartridge of the present embodiment including the above-described image carrier, charging unit, and resin film is mounted, An image holding member, a charging unit, and a resin film may be provided directly.

Hereinafter, an example of the image forming apparatus of the present embodiment will be described with reference to FIGS. 10, 11, and 12.
FIG. 10 is a cross-sectional view schematically showing a basic configuration of the image forming apparatus according to the first embodiment.
An image forming apparatus 200 shown in FIG. 10 includes an electrophotographic photosensitive member 207, a charging device 208 that charges the electrophotographic photosensitive member 207, a power source 209 connected to the charging device 208, and an electrophotographic image that is charged by the charging device 208. An exposure device 206 that exposes the photosensitive member 207 to form a latent image, a developing device 211 that develops the latent image formed by the exposure device 206 with toner and forms a toner image, and a toner that is formed by the developing device 211 The image forming apparatus includes a transfer device 212 that transfers an image to an object to be transferred (image output medium) 500, a cleaning device 213, a static eliminator 214, and a fixing device 215. In this case, the static eliminator 214 may not be provided.

Further, in the image forming apparatus 200, the oxygen atom content measured by (XPS) of the surface in contact with the electrophotographic photosensitive member 207 between the electrophotographic photosensitive member 207 and the charging device 208, and the inner side of the surface. Resin having a difference in oxygen atom content measured by X-ray electron spectroscopy (XPS) of 1 atom% or more and 20 atom% or less and a wetting tension of a surface in contact with the electrophotographic photoreceptor 207 of 35 mN / m or more and 55 mN / m or less The film 240 is sandwiched in such a manner that it can be detached. The resin film 240 suppresses friction and peeling between the electrophotographic photosensitive member 207 and the charging device 208 before using the image forming apparatus 200, and suppresses the occurrence of charging history of the electrophotographic photosensitive member 207.
The resin film 240 is removed when the image forming apparatus 200 is used.
However, when the image forming apparatus 200 is not used (during storage or the like), the resin film 240 is again between the electrophotographic photoreceptor 207 and the charging device 208 (XPS) on the surface in contact with the electrophotographic photoreceptor 207. The surface in contact with the electrophotographic photosensitive member 207 has a difference between the oxygen atom content measured by X-ray and the oxygen atom content measured by X-ray electron spectroscopy (XPS) inside the surface from 1 atom% to 20 atom% It may be inserted in a direction in which the wetting tension is 35 mN / m or more and 55 mN / m or less.

Here, the developing device 211 supplies toner to the electrophotographic photosensitive member 207. The photosensitive layer preferably contains the hydroxygallium phthalocyanine pigment, and may be any of the photosensitive layers shown in FIGS. 3, 4, 5, and 6, for example.
The charging device 208 in FIG. 10 is of a type (contact charging method) in which a conductive member (charging roll) is brought into contact with the surface of the electrophotographic photosensitive member 207 to charge the surface of the photosensitive member 207 (contact charging method). The charging device of this embodiment is used.

  As the exposure device 206, for example, an optical system device that exposes a light source such as a semiconductor laser, an LED (light emitting diode), a liquid crystal shutter, or the like on the surface of the electrophotographic photosensitive member in a desired image-like manner is used.

  The toner used in the present embodiment includes, for example, a binder resin and a colorant. Examples of the binder resin include homopolymers and copolymers such as styrenes, monoolefins, vinyl esters, α-methylene aliphatic monocarboxylic acid esters, vinyl ethers, vinyl ketones, and the like. As the binder resin, polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyethylene And polypropylene. Furthermore, polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin wax, and the like can also be mentioned.

  Coloring agents include magnetic powders such as magnetite and ferrite, carbon black, aniline blue, calcoil blue, chrome yellow, ultramarine blue, dupont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, and lamp black. Rose Bengal, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 57: 1, C.I. I. Pigment yellow 97, C.I. I. Pigment yellow 17, C.I. I. Pigment blue 15: 1, C.I. I. Pigment Blue 15: 3 is a typical example.

The toner may be internally added or externally added with known additives such as a charge control agent, a release agent, and other inorganic particles.
Typical examples of the release agent include low molecular weight polyethylene, low molecular weight polypropylene, Fischer-Tropsch wax, montan wax, carnauba wax, rice wax, and candelilla wax.
Known charge control agents are used, but charge control agents such as azo metal complex compounds, metal complex compounds of salicylic acid, and resin types containing polar groups may be used.
As other inorganic particles, small-diameter inorganic particles having an average primary particle diameter of 40 nm or less may be used, and if necessary, inorganic or organic particles having a larger diameter may be used in combination. As these other inorganic particles, known ones are used.

Moreover, you may surface-treat about a small diameter inorganic particle.
As a method for producing the toner used in the exemplary embodiment, a polymerization method such as an emulsion polymerization aggregation method or a dissolution suspension method is preferably used. In addition, a manufacturing method may be performed in which the toner obtained by the above method is used as a core, and agglomerated particles are further adhered and heat-fused to give a core-shell structure. When the external additive is added, the toner and the external additive are mixed by a Henschel mixer or a V blender. In addition, when the toner is manufactured by a wet method, it may be externally added by a wet method.
The transfer device 212 supplies a current having a predetermined current density to the electrophotographic photosensitive member when the toner image formed on the electrophotographic photosensitive member 207 is transferred to the transfer target member 500. Is preferred.

The cleaning device 213 is for removing residual toner adhering to the surface of the electrophotographic photosensitive member after the transfer process. The cleaned electrophotographic photosensitive member is repeatedly used for the image forming process described above. . As the cleaning device, for example, brush cleaning, roll cleaning, and the like are used in addition to the cleaning blade. Among these, it is preferable to use the cleaning blade. Examples of the material for the cleaning blade include urethane rubber, neoprene rubber, and silicone rubber.
Further, the image forming apparatus of the present embodiment may further include an erase light irradiation device 214 as shown in FIG.

FIG. 11 is a cross-sectional view schematically showing a basic configuration of an image forming apparatus according to the second embodiment.
The image forming apparatus 210 shown in FIG. 11 transfers the toner image formed on the electrophotographic photosensitive member 207 to the primary transfer member 212a, and then is supplied between the primary transfer member 212a and the secondary transfer member 212b. A transfer device of an intermediate transfer method for transferring to a transfer target (image output medium) 500, and at the time of such transfer, a current having a predetermined current density from the primary transfer member 212a toward the electrophotographic photosensitive member. Is to be supplied. Although not shown in FIG. 11, the image forming apparatus 210 may further include a static eliminator as in the image forming apparatus 200 shown in FIG. Further, as the other configuration of the image forming apparatus 210, the configuration of the image forming apparatus 200 is employed as it is.
The image forming apparatus 210 is different in that the intermediate transfer method is applied as described above.

Further, in the image forming apparatus 210, the oxygen atom content measured by X-ray electron spectroscopy (XPS) of the surface in contact with the electrophotographic photosensitive member 207 between the electrophotographic photosensitive member 207 and the charging device 208, and The difference in oxygen atom content measured by X-ray electron spectroscopy (XPS) inside the surface is 1 atom% or more and 20 atom% or less, and the wetting tension of the surface in contact with the electrophotographic photoreceptor 207 is 35 mN / m or more and 55 mN / The resin film 240 which is m or less is sandwiched in such a manner that it can be detached. The resin film 240 suppresses friction and peeling between the electrophotographic photosensitive member 207 and the charging device 208 before using the image forming apparatus 210, and suppresses the occurrence of charging history of the electrophotographic photosensitive member 207.
The resin film 240 is removed when the image forming apparatus 210 is used.
However, when the image forming apparatus 210 is not used (during storage or the like), the resin film 240 is again disposed between the electrophotographic photosensitive member 207 and the charging device 208 on the surface in contact with the electrophotographic photosensitive member 207. The difference between the oxygen atom content measured by spectroscopy (XPS) and the oxygen atom content measured by X-ray electron spectroscopy (XPS) inside the surface is 1 atom% or more and 20 atom% or less. You may insert in the direction from which the wetting tension of the surface which contact | connects the body 207 will be 35 mN / m or more and 55 mN / m or less.

FIG. 12 is a schematic configuration diagram illustrating a 4-color tandem multicolor image forming apparatus which is an image forming apparatus according to the third embodiment.
As shown in FIG. 12, the image forming apparatus according to the third embodiment is an image of each color of yellow (Y), magenta (M), cyan (C), and black (K) based on the color-separated image data. Are provided with first to fourth image forming stations 10Y, 10M, 10C, and 10K (image forming means). These image forming stations (hereinafter simply referred to as “stations”) 10Y, 10M, 10C, and 10K are juxtaposed at a predetermined distance from each other in a substantially horizontal direction. The stations 10Y, 10M, 10C, and 10K may be process cartridges (process cartridges according to the present embodiment) that can be mounted on the image forming apparatus main body.

  Above each station 10Y, 10M, 10C, 10K, an intermediate transfer belt 20 as an intermediate transfer member is extended through each station. The intermediate transfer belt 20 is provided by being wound around a driving roller 22 and a support roller 24 that are in contact with the inner surface of the intermediate transfer belt 20 that are spaced apart from each other, and run endlessly in the direction from the first station 10Y to the fourth station 10K. It has come to be. The support roller 24 is urged away from the driving roller 22 by a spring or the like (not shown), and tension is applied to the intermediate transfer belt 20 wound between the two. An intermediate transfer member cleaning device 30 is provided on the side surface of the electrophotographic photosensitive member of the intermediate transfer belt 20 so as to face the drive roller 22.

  Since the first to fourth stations 10Y, 10M, 10C, and 10K described above have substantially the same configuration, here, the first station that forms a yellow image disposed on the upstream side in the running direction of the intermediate transfer belt. 10Y will be described as a representative. Note that the same reference numerals with magenta (M), cyan (C), and black (K) are attached to the same parts as the first station 10Y instead of yellow (Y), so that the second to fourth Description of the stations 10M, 10C, and 10K is omitted.

The first station 10Y has an electrophotographic photoreceptor 1Y that functions as an electrophotographic photoreceptor. Around the electrophotographic photoreceptor 1Y, there is a charging roller (charging member) 2Y for charging the surface of the electrophotographic photoreceptor 1Y to a predetermined potential, and a laser beam 3Y based on an image signal obtained by color-separating the charged surface. An exposure device 3 that forms an electrostatic latent image by exposure, a developing device 4Y that supplies a charged toner (developer) to the electrostatic latent image and develops the electrostatic latent image, and a developed toner image (developer image) A primary transfer roller 5Y (primary transfer means) that transfers the toner onto the intermediate transfer belt 20, and a photoreceptor cleaning device 6Y that removes toner remaining on the surface of the electrophotographic photoreceptor 1Y after the primary transfer are sequentially disposed. ing.
The primary transfer roller 5Y is disposed inside the intermediate transfer belt 20 and is provided at a position facing the electrophotographic photoreceptor 1Y. Further, a bias power source (not shown) for applying a primary transfer bias is connected to each of the primary transfer rollers 5Y, 5M, 5C, and 5K. Each bias power source varies the transfer bias applied to each primary transfer roller under the control of a control unit (control means) (not shown).

Further, in the first station 10Y, the oxygen atom content measured by X-ray electron spectroscopy (XPS) of the surface in contact with the electrophotographic photosensitive member 1Y between the electrophotographic photosensitive member 1Y and the charging roller 2Y, and The difference in oxygen atom content measured by X-ray electron spectroscopy (XPS) on the inner side of the surface is 1 atom% or more and 20 atom% or less, and the wetting tension of the surface in contact with the electrophotographic photoreceptor 1Y is 35 mN / m or more and 55 mN / The resin film 8Y which is m or less is sandwiched in such a manner that it can be detached.
The resin film 8Y is removed when the image forming apparatus is used.
However, when the image forming apparatus is not used (during storage or the like), the resin film 8Y is again subjected to X-ray electron spectroscopy on the surface in contact with the electrophotographic photoreceptor 1Y between the electrophotographic photoreceptor 1Y and the charging roller 2Y. The difference between the oxygen atom content measured by the XPS method (XPS) and the oxygen atom content measured by the X-ray electron spectroscopy (XPS) inside the surface is 1 atom% or more and 20 atom% or less, and an electrophotographic photosensitive member It may be inserted in a direction in which the wetting tension of the surface in contact with 1Y is 35 mN / m or more and 55 mN / m or less.

Hereinafter, an operation of forming a yellow image in the first station 10Y will be described.
First, the resin film 8Y is removed.
Next, prior to the operation, the surface of the electrophotographic photoreceptor 1Y is charged to a potential of, for example, −800V or more and −600V or less by the charging roller 2Y.

The electrophotographic photoreceptor 1Y is formed by laminating a photosensitive layer on a conductive substrate. This photosensitive layer usually has a high resistance, but has a property that the specific resistance of the portion irradiated with the laser beam changes when irradiated with the laser beam 3Y. Therefore, a laser beam 3Y is output to the surface of the charged electrophotographic photoreceptor 1Y via the exposure device 3 in accordance with yellow image data sent from a control unit (not shown). The laser beam 3Y is applied to the photosensitive layer on the surface of the electrophotographic photoreceptor 1Y, whereby an electrostatic latent image of a yellow print pattern is formed on the surface of the electrophotographic photoreceptor 1Y.
The electrostatic latent image is an image formed on the surface of the electrophotographic photoreceptor 1Y by charging, and the specific resistance of the irradiated portion of the photosensitive layer is lowered by the laser beam 3Y, and the surface of the electrophotographic photoreceptor 1Y is reduced. This is a so-called negative latent image formed by the flow of the charged electric charge while the electric charge of the portion not irradiated with the laser beam 3Y remains.

  The electrostatic latent image formed on the electrophotographic photoreceptor 1Y in this way is rotated to a predetermined development position as the electrophotographic photoreceptor 1Y travels. At this development position, the electrostatic latent image on the electrophotographic photosensitive member 1Y is converted into a visible image (toner image) by the developing device 4Y.

In the developing device 4Y, for example, the volume average particle size formed of at least a yellow colorant, a wax, a binder resin, and an aliphatic hydrocarbon-copolymer petroleum resin having 9 or more carbon atoms is 7 μm. Contains yellow toner. The yellow toner is triboelectrically charged by being agitated inside the developing device 4Y, and has the same polarity (negative polarity) as that of the charged electric charge on the electrophotographic photoreceptor 1Y. As the surface of the electrophotographic photosensitive member 1Y passes through the developing device 4Y, yellow toner is electrostatically attached only to the latent image portion on the surface of the electrophotographic photosensitive member 1Y, and the latent image becomes yellow toner. It is developed by. The electrophotographic photosensitive member 1Y on which the yellow toner image is formed continues to run at a predetermined speed, and the toner image developed on the electrophotographic photosensitive member 1Y is conveyed to a predetermined primary transfer position.
When the yellow toner image on the electrophotographic photoreceptor 1Y is conveyed to the primary transfer, a predetermined primary transfer bias is applied to the primary transfer roller 5Y, and the electrophotographic photoreceptor 1Y moves toward the primary transfer roller 5Y. The electrostatic force is applied to the toner image, and the toner image on the electrophotographic photoreceptor 1Y is transferred onto the intermediate transfer belt 20. The transfer bias applied at this time is a (+) polarity opposite to the polarity (−) of the toner. For example, in the first station 10Y, a constant current is controlled to about +10 μA by a control unit (not shown). .

  Further, the primary transfer bias applied to the primary transfer rollers 5M, 5C, and 5K after the second station 10M is also controlled as described above.

  Thus, the intermediate transfer belt 20 to which the yellow toner image is transferred at the first station 10Y is sequentially conveyed through the second to fourth stations 10M, 10C, and 10K, and the toner images of the respective colors are superimposed as described above to perform multiple transfer. Is done.

  The intermediate transfer belt 20 on which the toner images of all the colors are transferred through the first to fourth stations is transferred to the intermediate transfer belt 20, the support roller 24 in contact with the inner surface of the intermediate transfer belt 20, and the image holding surface side of the intermediate transfer belt 20. The secondary transfer roller (secondary transfer unit) 26 arranged to the secondary transfer portion is provided. On the other hand, the recording paper (transfer material) P is fed at a predetermined timing between the secondary transfer roller 26 and the intermediate transfer belt 20 via the supply mechanism, and a predetermined secondary transfer bias is applied to the support roller 24. Applied. The transfer bias applied at this time is a (−) polarity that is the same polarity as the polarity (−) of the toner, and an electrostatic force from the intermediate transfer belt 20 toward the recording paper P is applied to the toner image, and the transfer bias is applied to the intermediate transfer belt 20. The toner image is transferred onto the recording paper P. The secondary transfer bias at this time is determined according to the resistance detected by a resistance detection means (not shown) for detecting the resistance of the secondary transfer portion, and is controlled by a constant voltage.

  Thereafter, the recording paper P is fed into the fixing device 28, the toner image is heated, and the color-superposed toner image is melted and permanently fixed on the recording paper P. The recording paper P on which the color image has been fixed is carried out toward the discharge unit, and a series of color image forming operations is completed.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

(Preparation of charging roll 1)
-Formation of conductive elastic layer-
A mixture having the following composition is kneaded with an open roll, and a roll with a diameter of 15 mm is formed on the surface of a conductive support made of SUS303 with a diameter of 8 mm using a press molding machine through an adhesive layer, and then polished to have a diameter of 14 mm. Elastic roll A was obtained.
Rubber material (epichlorohydrin-ethylene oxide-allyl glycidyl ether copolymer rubber Gechron 3106: manufactured by Nippon Zeon Co., Ltd.): Conductive agent (carbon black Asahi Thermal: manufactured by Asahi Carbon Co.): 15 parts by mass Conductive agent (Ketjen Black) EC: manufactured by Lion Co., Ltd.): 5 parts by mass, ionic conductive agent (lithium perchlorate): 1 part by mass, vulcanizing agent (sulfur 200 mesh: manufactured by Tsurumi Chemical Co., Ltd.): 1 part by mass, vulcanization accelerator (Noxeller) DM: Ouchi Shinsei Chemical Co., Ltd.): 2.0 parts by mass, vulcanization accelerator (Noxeller TT: Ouchi Shinsei Chemical Co., Ltd.): 0.5 parts by mass, vulcanization accelerator (zinc oxide, zinc oxide) 1 type: manufactured by Shodo Chemical Co., Ltd.): 3 parts by mass, stearic acid: 1.5 parts by mass

-Formation of surface layer-
Dispersion A obtained by dispersing a mixture having the following composition with a bead mill was diluted with MEK (methyl ethyl ketone), dip-coated on the surface of the conductive elastic roll A, and then heated and dried at 180 ° C. for 30 minutes, A surface layer having a thickness of 7 μm was formed to obtain a charging roll 1.
-Polymer material (saturated copolymer polyester resin solution Byron 30SS: manufactured by Toyobo Co., Ltd.): 100 parts by mass-Curing agent (amino resin solution Super Becamine G-821-60: manufactured by Dainippon Ink & Chemicals, Inc.): 26. 3 parts by mass / conductive agent (carbon black FW200: manufactured by Degussa): 10 parts by mass

(Preparation of electrophotographic photoreceptor 1)
Zinc oxide: (average particle size 70 nm: manufactured by Teica Co., Ltd .: specific surface area value 15 m ² / g) 100 parts by mass with 500 parts by mass of tetrahydrofuran was stirred and mixed, and silane coupling agent (KBM603: manufactured by Shin-Etsu Chemical Co., Ltd.) 1.25 mass Part was added and stirred for 2 hours. Thereafter, toluene was distilled off under reduced pressure and baked at 120 ° C. for 3 hours to obtain a silane coupling agent surface-treated zinc oxide pigment.

60 parts by mass of the zinc oxide pigment subjected to the surface treatment, 0.6 parts by mass of alizarin, 13.5 parts by mass of a curing agent: blocked isocyanate (Sumijoule 3175: manufactured by Sumitomo Bayern Urethane Co., Ltd.), and a butyral resin (BM) -1: manufactured by Sekisui Chemical Co., Ltd.) 15 parts by mass, a solution of 38 parts by mass of methyl ethyl ketone dissolved in 85 parts by mass of methyl ethyl ketone, and 25 parts by mass of methyl ethyl ketone were mixed, and 2 hours in a sand mill using 1 mmφ glass beads. Dispersion was performed to obtain a dispersion. To the obtained dispersion, 0.005 parts by mass of dioctyltin dilaurate as a catalyst and 4.0 parts by mass of silicone resin particles (Tospearl 145: manufactured by GE Toshiba Silicone) are added, and an undercoat layer coating solution is added. Got.
This coating solution was applied onto an aluminum substrate by a dip coating method, followed by drying and curing at 170 ° C. for 40 minutes to obtain an undercoat layer having a thickness of 25 μm.

Next, a photosensitive layer (photosensitive layer having a laminated structure of a charge generation layer and a charge transport layer) was formed on the formed undercoat layer as follows.
First, the Bragg angles (2θ ± 0.2 °) of the X-ray diffraction spectrum using Cukα rays as charge generation materials are at least 7.3 °, 16.0 °, 24.9 °, 28.0 °. 15 parts by mass of hydroxygallium phthalocyanine having a diffraction peak at a position, 10 parts by mass of vinyl chloride-vinyl acetate copolymer resin (VMCH, manufactured by Nihon Unicar) as a binder resin, 200 parts by mass of n-butyl acetate, The mixture consisting of was dispersed in a sand mill for 4 hours using 1 mmφ glass beads. To the obtained dispersion, 175 parts by mass of n-butyl acetate and 180 parts by mass of methyl ethyl ketone were added and stirred to obtain a coating solution for a charge generation layer.
The charge generation layer coating solution was dip coated on the undercoat layer and dried at room temperature (22 ° C.) to form a charge generation layer having a thickness of 0.2 μm.

Next, 1 part by mass of tetrafluoroethylene resin particles, 0.02 part by mass of a fluorine-based graft polymer, 5 parts by mass of tetrahydrofuran, and 2 parts by mass of toluene are sufficiently stirred and mixed. A turbid liquid was obtained.
Next, 4 parts by mass of N, N′-diphenyl-N, N′-bis (3-methylphenyl)-[1,1 ′] biphenyl-4,4′-diamine as a charge transport material, and bisphenol Z type After 6 parts by mass of polycarbonate resin (viscosity average molecular weight 40,000) and 23 parts by mass of tetrahydrofuran were mixed and dissolved in 10 parts by mass of toluene, the tetrafluoroethylene resin particle suspension was added and stirred and mixed. Dispersion by increasing the pressure to 400 Kgf / cm ² (3.92 × 10 ⁻¹ Pa) using a high-pressure homogenizer (trade name LA-33S, manufactured by Nanomizer Co., Ltd.) equipped with a through-type chamber having a fine flow path. The treatment was repeated 6 times to obtain a tetrafluoroethylene resin particle dispersion. Further, 0.2 parts by mass of 2,6-di-t-butyl-4-methylphenol was mixed to obtain a coating solution for forming a charge transport layer. This coating solution was applied onto the charge generation layer and dried at 115 ° C. for 40 minutes to form a charge transport layer having a thickness of 24 μm.
Thus, an electrophotographic photosensitive member 1 having a charge generation layer and a charge transport layer in this order on the undercoat layer was obtained.

(Preparation of electrophotographic photoreceptor 2)
An electrophotographic photosensitive member was produced in the same manner as the electrophotographic photosensitive member 1 except that the thickness of the charge transport layer was 29 μm.

(Preparation of electrophotographic photoreceptor 3)
An electrophotographic photosensitive member was produced in the same manner as the electrophotographic photosensitive member 1 except that the thickness of the charge transport layer was 34 μm.

(Preparation of electrophotographic photoreceptor 4)
An electrophotographic photosensitive member was produced in the same manner as the electrophotographic photosensitive member 1 except that the thickness of the charge transport layer was 40 μm.

(Preparation of resin film 1)
One side of a low-density polyethylene having a thickness of 30 μm was corona treated under the following conditions to obtain a resin film having an oxygen atom content of 2 atom% as measured by X-ray electron spectroscopy (XPS).
Corona discharge treatment conditions Discharge power: 500W
Discharge electrode length: 0.5m
Sheet processing speed: 50 m / min Sheet / electrode distance: 1 mm

  The difference between the oxygen atom content measured by X-ray electron spectroscopy (XPS) on the surface in contact with the image carrier and the oxygen atom content measured by X-ray electron spectroscopy (XPS) inside the surface, image retention The oxygen atom content on the surface in contact with the body and the wetting tension on the surface in contact with the image carrier were measured by the methods described above.

(Production of resin films 2 to 6)
A resin film was prepared in the same manner as the resin film 1 except that the discharge power and the sheet processing speed were changed as shown in Table 1.

(Preparation of resin film 7)
A resin film was prepared in the same manner as the resin film 2 except that both sides were treated.

(Preparation of resin film 8)
A resin film was prepared in the same manner as the resin film 1 except that the treatment was not performed.

(Preparation of resin film 9)
A resin film was prepared in the same manner as the resin film 2 except that high-density polyethylene having a thickness of 30 μm was used.

(Preparation of resin film 10)
A resin film was prepared in the same manner as the resin film 2 except that polypropylene having a thickness of 30 μm was used.

(Preparation of resin film 11)
A resin film was prepared in the same manner as the resin film 3 except that polyethylene terephthalate having a film thickness of 30 μm was used.

(Preparation of resin film 12)
A resin film was produced in the same manner as the resin film 11 except that the treatment was not performed.

(Preparation of resin film 13)
A resin film was prepared in the same manner as the resin film 3 except that polyamide (nylon 6) having a thickness of 30 μm was used.

(Preparation of resin film 14)
A resin film was prepared in the same manner as the resin film 13 except that the treatment was not performed.

  Material of each resin film, discharge power, sheet processing speed, oxygen atom content measured by X-ray electron spectroscopy (XPS) on the surface in contact with the electrophotographic photosensitive member, and X-ray electron spectroscopy (XPS) inside the surface ), The oxygen atom content measured by X-ray electron spectroscopy (XPS) of the surface in contact with the electrophotographic photosensitive member, and the wetting tension of the surface in contact with the electrophotographic photosensitive member. It is shown in 1.

  The “difference in oxygen atom content (*)” in Table 1 above refers to the oxygen atom content measured by X-ray electron spectroscopy (XPS) on the surface in contact with the electrophotographic photosensitive member, and the inside of the surface. Represents the difference in oxygen atom content measured by X-ray electron spectroscopy (XPS).

<Example 1>
(Production of process cartridge)
The resin film 1 is sandwiched between the charging roll 1 and the electrophotographic photosensitive member 1 and mounted on a drum cartridge of a color copying machine DocuCenter Color a450 (manufactured by Fuji Xerox Co., Ltd.). As a process cartridge of Example 1, A drum cartridge 1 was obtained.

(Evaluation)
Using the drum cartridge 1, the following tests and evaluations were performed.
The evaluation results are shown in Table 2.

-Vibration test-
The drum cartridge 1 was vibrated with an amplitude of 25 mm, a frequency of 10 Hz, and an acceleration of 7 mm / s ² for 1 hour.

-Image quality evaluation-
After removing (removing) the resin film of the drum cartridge 1 after the vibration test, the drum cartridge 1 is mounted on the DocuCenter Color a450, and a 50% halftone of magenta is printed with A3. The image quality of the 50th sheet was evaluated. The printing environment was 22 ° C. and 55% RH.

The indexes for image quality evaluation are as follows.
The color difference (ΔE * ab) between the color streak portion measured by X-Rite 938 (manufactured by X-Rite Co., Ltd.) and its periphery is A: 0.5 or less (density unevenness has not occurred)
B: More than 0.5 and less than 1.0 (Minor density unevenness occurs)
C: More than 1.0 and less than 2.0 (density unevenness occurs)
D: 2.0 or more (strong density unevenness occurs)
It is desirable that all be A, but it is acceptable if the first sheet is C, B is by the 10th sheet, and A is by the 50th sheet.

-Storage test-
Moreover, it stored for 7 days at 40 degreeC and 90% RH in the state which pinched | interposed the resin film (storage test).
The first image after the storage test was evaluated in the same manner as described above, and the presence or absence of image defects was evaluated.
The evaluation results are shown in Table 2 below.

<Examples 2 to 12, Comparative Examples 1 to 5>
In Example 1, a process cartridge was prepared in the same manner as in Example 1 except that the types of the resin film and the electrophotographic photosensitive member were changed as shown in Table 2 below, and the same evaluation as in Example 1 was performed.
The evaluation results are shown in Table 2 below.

1Y, 1M, 1C, 1K, 11, 58, 207 Electrophotographic photosensitive member (image carrier)
2Y, 2M, 2C, 2K, 56, 208 Charging roller (charging means)
3,206 Exposure device 4Y, 4M, 4C, 4K, 211 Developing device 5Y, 5M, 5C, 5K, 26, 212 Transfer roller (transfer device)
5Y, 5M, 5C, 5K, 213 Cleaning device 12 Conductive substrate 13 Photosensitive layer 15 Charge generation layer 16 Charge transport layer 17 Protective layer 20 Intermediate transfer belt 31 Conductive support 32 Elastic layer 33 Surface layer 34 Resistive layer 40, 240 , 8Y, 8M, 8C, 8K Resin film 42 Surface in contact with image carrier 44 Surface in contact with charging means 200, 210 Image forming apparatus 209 Power supply 216 Rail 217, 218 Opening 300 Process cartridge

Claims (8)

An image carrier,
Charging means for charging the surface of the image carrier in contact with the image carrier;
The oxygen atom content measured by X-ray electron spectroscopy (XPS) of the surface that is sandwiched between the image carrier and the charging unit and is in contact with the image carrier, and on the inner side of the surface Resin film having a difference in oxygen atom content measured by X-ray electron spectroscopy (XPS) of 1 atom% or more and 20 atom% or less and a wetting tension of a surface in contact with the image carrier of 35 mN / m or more and 55 mN / m or less When,
And a process cartridge that is detachable from the image forming apparatus.   The process cartridge according to claim 1, wherein at least a surface in contact with the image carrier in the resin film contains polyolefin as a main component.   3. The process cartridge according to claim 1, wherein the resin film has an oxygen atom content of 1 atom% or more and 20 atom% or less measured by X-ray electron spectroscopy (XPS) on a surface in contact with the image carrier.   4. The process cartridge according to claim 1, wherein the image carrier has a charge generation layer and a charge transport layer having a thickness of 30 μm or more in this order on a conductive substrate. 5. An image carrier,
Charging means for charging the surface of the image carrier in contact with the image carrier;
The oxygen atom content measured by X-ray electron spectroscopy (XPS) of the surface that is sandwiched between the image carrier and the charging unit and is in contact with the image carrier, and on the inner side of the surface Resin film having a difference in oxygen atom content measured by X-ray electron spectroscopy (XPS) of 1 atom% or more and 20 atom% or less and a wetting tension of a surface in contact with the image carrier of 35 mN / m or more and 55 mN / m or less When,
Latent image forming means for forming a latent image on the surface of the charged image carrier;
Developing means for developing a latent image formed on the surface of the image carrier with toner to form a toner image;
Transfer means for transferring a toner image formed on the surface of the image carrier to a recording medium;
An image forming apparatus.   The image forming apparatus according to claim 5, wherein at least a surface in contact with the image carrier in the resin film contains polyolefin as a main component.   The image forming apparatus according to claim 5, wherein the resin film has an oxygen atom content of 1 atom% or more and 20 atom% or less measured by X-ray electron spectroscopy (XPS) on a surface in contact with the image carrier. .   8. The image forming apparatus according to claim 5, wherein the image carrier has a charge generation layer and a charge transport layer having a thickness of 30 μm or more in this order on a conductive substrate.