JP5531469B2 - Process cartridge and image forming apparatus - Google Patents

Description

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

  An image forming apparatus using an electrophotographic method forms a uniform charge on an image carrier (photoreceptor), forms an electrostatic latent image with a laser or the like that modulates an image signal, and then uses the charged toner to The electrostatic latent image is developed into a toner image. Then, a desired transfer image can be obtained by electrostatically transferring the toner image to the recording material medium through an intermediate transfer member or directly.

  As described above, in an image forming apparatus using an electrophotographic system, a charging process for forming a uniform charge on an image carrier is performed. One type of charging member that performs such a charging process is a contact-type charging member. Such a contact-type charging member generally has a small current to be applied, and has an advantage that the amount of ozone generated is very small compared to a corotron or scorotron that is a non-contact-type charging member.

  When such a contact-type charging member is used, the charging member is disposed in contact with the image carrier, and therefore, during the process from manufacturing to physical distribution, friction or peeling at the portion where the charging member and the image carrier are in contact with each other. May cause electrification. The charges generated in this way are accumulated on the surface of the image carrier, causing uneven charging when the image forming apparatus is used for the first time, and black streaks and whites corresponding to the contact area between the charging member and the image carrier. There is a problem of causing image defects such as streaks. Another problem is that several to several tens of prints are required to remove the charging history on the surface of the image carrier.

  On the other hand, a method of interposing a powder made of a substance having a charge column level on the positive side of a substance existing on the surface of the image carrier between the charging member and the image carrier (see Patent Document 1), 2 Means for suppressing charging unevenness such as a method of interposing a sheet member made of various types of resin layers (see Patent Documents 2 and 3) has been proposed.

JP-A-7-84432 JP 2002-258719 A JP-A-4-140770

  SUMMARY OF THE INVENTION An object of the present invention is to provide a process cartridge and an image forming apparatus that can suppress uneven charging in the initial stage of use and prevent image defects.

  The above-mentioned subject is achieved by the following present invention. That is, the process cartridge and the image forming apparatus of the present invention have the following characteristics.

(1) An image carrier and charging means for contacting the surface of the image carrier with a charging member to charge the surface of the image carrier, and a resin provided on one end of the substrate opposite to the direction to be pulled off during use and a surface layer seen including, a first resin layer and second resin layer is formed between the resin surface layer and the base material, the resistance of the resin surface layer in contact with the image bearing member and said base member The resistance value of the first resin layer in contact with the sheet member is lower than the resistance value of the second resin layer so that the resin surface layer is in contact with the image carrier between the unused image carrier and the charging member. It is a process cartridge that is interposed and used when the sheet member is pulled out during use.

(2) the resin surface layer is a polyolefin, fluorocarbon resins, silicone resins, polyurethanes, polyesters, acrylic copolymers, polyamides, polyimides, phenolic resins, the above (1) made of a resin selected from the group consisting of polyacetal It is a process cartridge of description.

( 3 ) An image carrier and a charging means that contacts the image carrier and charges the surface with a charging member, and a resin provided on one end of the substrate opposite to the direction to be pulled off during use A sheet member including a surface layer is interposed between the unused image carrier and the charging member so that the resin surface layer is in contact with the image carrier, and an end portion of the interposed sheet member includes the image member. It is a process cartridge having a folded portion folded back on the carrier side.

( 4 ) An image forming apparatus including the process cartridge according to any one of (1) to ( 3 ).

  According to the first aspect of the present invention, as compared with the prior art, uneven charging at the initial stage of use is suppressed and image defects are prevented.

Further, according to the invention described in claim 1, when the charging member and the image bearing member is transported in contact, even if the charge on the surface of the image bearing member in contact with the image bearing member is generated, resulting The charge is transferred to the surface resin layer having a relatively low resistance value, and accumulation of charge on the surface of the image carrier is suppressed, so that charging unevenness in the initial stage of use is suppressed and image defects are prevented.

According to the second aspect of the present invention, charging unevenness in the initial stage of use is suppressed and image defects are prevented as compared with the conventional case.

According to the third aspect of the present invention, during conveyance, the interposition sheet member is prevented from dropping between the image carrier and the charging member, and charging unevenness in the initial stage of use is suppressed and image defects are prevented. The

According to the invention described in claim 4 , as compared with the prior art, uneven charging at the initial stage of use is suppressed and image defects are prevented.

It is a top view which shows an example of a structure of the sheet | seat member in this invention. It is sectional drawing along the AA line of FIG. It is a top view which shows the other example of a structure of the sheet | seat member in this invention. It is sectional drawing along the BB line of FIG. It is a top view which shows the other example of a structure of the sheet | seat member in this invention. It is sectional drawing along CC line of FIG. It is a top view which shows the other example of a structure of the sheet | seat member in this invention. It is sectional drawing along the DD line of FIG. 1 is a cross-sectional view schematically showing a basic configuration of an image forming apparatus according to a first embodiment of the present invention. It is sectional drawing which shows schematically the basic composition of the image forming apparatus which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows schematically the basic composition of the image forming apparatus which concerns on 3rd Embodiment of this invention. 1 is a cross-sectional view schematically showing a preferred embodiment of a process cartridge of the present invention. 1 is a schematic cross-sectional view showing a preferred embodiment of an electrophotographic photosensitive member in the present embodiment. It is a schematic cross section which shows other suitable embodiment of the electrophotographic photosensitive member in this Embodiment. It is a schematic cross section which shows other suitable embodiment of the electrophotographic photosensitive member in this Embodiment. It is a schematic cross section which shows other suitable embodiment of the electrophotographic photosensitive member in this Embodiment. FIG. 2 is a schematic cross-sectional view of an example of a process cartridge in which a sheet member is interposed between an unused image carrier and a charging member in the present embodiment. FIG. 6 is a schematic cross-sectional view of another example of a process cartridge in which a sheet member is interposed between an unused image carrier and a charging member in the present embodiment. It is a schematic sectional drawing of the apparatus structure for evaluating the frictional resistance of resin which comprises a resin surface layer. It is a figure explaining the measuring method of resistivity.

  Embodiments of the present invention will be described below. In addition, the dimension of each structure of drawing may differ from an actual dimension.

  The process cartridge according to the present embodiment is attachable to the image forming apparatus, and includes an image carrier and a charging member that contacts the image carrier, and the image carrier and the charging member. It is only necessary that a sheet member is interposed between the members, and other configurations are not particularly limited. Hereinafter, the charging member, the image carrier, and the sheet member constituting the process cartridge according to the present embodiment will be described.

[Charging member]
The charging member used 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 has a voltage. It is a conductive member that is applied and used.

  In this embodiment, in order to obtain a higher effect, the charging member is particularly preferably a 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.

  Hereinafter, the conductive support, the conductive elastic layer, the resistance layer, and the surface layer constituting the charging roll which is the most preferable aspect of the charging member in the present embodiment will be described in detail. These constituent members can be used in the same manner 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 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 the electronic conductive agent include carbon black such as ketjen black and acetylene black; pyrolytic carbon, graphite; various conductive metals or alloys such as aluminum, copper, nickel, stainless steel; tin oxide, indium oxide, titanium oxide Examples thereof include fine powders such as 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 Can be mentioned.

  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, the amount is preferably in the range of 1 part by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the rubber material. More preferably, it is in the range of 25 parts by mass or less. On the other hand, in the case of the ionic conductive agent, it is preferably in a range of 0.1 parts by mass or more and 5.0 parts by mass or less, and 0.5 parts by mass or more, 3.0 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.

  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 Fluoro rubber, 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 or more and 100,000 or less, and more preferably in the range of 10,000 or more and 50,000 or less.

  The surface layer is preferably constituted by using the conductive agent and various fine 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 mass part or more and 50 mass parts or less with respect to 100 mass parts of polymeric materials, In the range of 5 mass parts or more and 20 mass parts or less. More preferably.

  As fine particles used for the surface layer, metal oxides such as silicon oxide, aluminum oxide, 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.

[Sheet material]
The sheet member in the present embodiment includes a base material made of a nonwoven fabric and a resin surface layer, and is interposed between an image carrier of an unused process cartridge and a charging member. The process cartridge in the present embodiment is used with the sheet member removed during use. Here, the “nonwoven fabric” is a sheet-like material in which fibers are combined without weaving or knitting, such as printing paper such as high-quality paper or coated paper, wrapping paper such as kraft paper, Rasha paper, Kent paper, etc. Used to mean paper and conductive paper containing a conductive agent.

  Next, the configuration of the sheet member in the present embodiment will be described with reference to FIGS. First, as shown in FIG. 1, the sheet member 20 has a resin surface layer 24 formed in the region of the base material 22 corresponding to the nip portion between the image carrier of the unused process cartridge and the charging member. The surface layer 24 is provided on the side opposite to the direction in which the sheet member 20 is pulled out during use. Further, as shown in FIG. 2 showing a cross section along the line AA in FIG. 1, the sheet member 20 has a base material 22 and a resin surface layer 24 locally, for example, in the longitudinal direction of the resin surface layer 24. The resin adhesive layer 26 adheres at the end. Here, the sheet member 20 is formed by adhering a sheet-like resin surface layer 24 to a base material 22 using an adhesive that forms the resin adhesive layer 26. Further, the size of the resin surface layer 24 is not particularly limited, but it is preferably formed in the entire region where the image carrier and the charging member are in contact with each other, and the printing direction shown in FIG. In the direction, the width of the resin surface layer 24 is not particularly limited, but is preferably wider than the image forming area of the image carrier. The size of the resin surface layer 24 shown in FIGS. 3 to 8 to be described later is also the same size as described above.

  As shown in FIG. 3, the sheet member 30 has a resin surface layer 24 formed in the region of the base material 22 corresponding to the nip portion between the image carrier of the unused process cartridge and the charging member. The surface layer 24 is provided on the side opposite to the direction in which the sheet member 20 is pulled out during use. Further, as shown in FIG. 4 showing a cross section taken along the line BB in FIG. 3, the base member 22 and the resin surface layer 24 of the sheet member 30 are bonded to each other by the resin adhesive layer 36. . Here, the sheet member 30 is formed by adhering the sheet-shaped resin surface layer 24 to the base material 22 using an adhesive that forms the resin adhesive layer 26.

  Further, as shown in FIG. 5, the sheet member 40 is an area of the base material 22 corresponding to the nip portion between the image carrier of the unused process cartridge and the charging member, and the sheet member 20 is pulled out during use. A resin surface layer 24 is formed on the opposite side. Further, as shown in FIG. 6 representing a cross section taken along the line CC in FIG. 5, the sheet member 40 has the resin surface layer 24 directly formed on the base material 22. In the sheet member 40 shown in FIGS. 5 and 6, the resin surface layer 24 may be formed by, for example, applying or casting a resin or a resin solution constituting the resin surface layer 24 described later on the base material 22, or The resin particles constituting the resin surface layer 24 may be formed by transferring using a normal image forming apparatus, or screen printing may be performed using the resin constituting the resin surface layer 24.

  Further, as shown in FIG. 7, the sheet member 50 has a resin surface layer 24 formed in the region of the base material 22 corresponding to the nip portion between the image carrier of the unused process cartridge and the charging member. The surface layer 24 is provided on the side opposite to the direction in which the sheet member 20 is pulled out during use. Furthermore, as shown in FIG. 8 representing a cross section along the line D-D in FIG. 7, the sheet member 50 is provided with a resin layer 28 between the base material 22 and the resin surface layer 24. The substrate 22 is bonded to the entire surface by a resin adhesive layer 36. Here, the sheet member 50 uses an adhesive that forms the resin adhesive layer 26, adheres a sheet-like resin layer 28 to the base material 22, and further attaches the resin surface layer 24 to the resin surface layer 24 described later. The constituent resin or resin solution may be formed by applying or casting to the resin layer 28, or the resin particles constituting the resin surface layer 24 may be formed by transferring using a normal image forming apparatus. Alternatively, screen printing may be performed using a resin constituting the resin surface layer 24.

  As shown in FIGS. 1 to 4 and FIGS. 7 and 8 described above, the sheet member in the present embodiment has one or more resin layers (including a resin adhesive layer) between the base material and the resin surface layer. In such a case, the resistance value of the resin surface layer 24 in contact with the image carrier is preferably lower than the resistance value of the resin layer on the substrate 22 side. Since the resistance value of the resin surface layer 24 in contact with the image carrier is lower than the resistance value of the resin layer on the substrate 22 side, when the charging member and the image carrier are conveyed in contact with each other, the contact with the image carrier is assumed. Even if charges are generated on the surface of the image carrier, the generated charges are transferred to the resin surface layer 24 having a relatively low resistance value. Therefore, charge accumulation on the surface of the image bearing member is suppressed, charging unevenness in the initial stage of use is suppressed, and image defects are prevented as compared with the conventional case.

  Further, as in the sheet member 50 shown in FIGS. 7 and 8, a first resin layer made of the resin adhesive layer 36 and a second resin layer made of the resin layer 28 are provided between the base material 22 and the resin surface layer 24. When formed, the resistance value of the resin surface layer 24 in contact with the image carrier and the resistance value of the resin adhesive layer 36 which is the first resin layer in contact with the substrate 22 are the resistance of the resin layer 28 which is the second resin layer. Preferably it is lower than the value. Since the resistance value of the resin surface layer 24 in contact with the carrier and the resistance value of the resin adhesive layer 36 as the first resin layer in contact with the base material 22 are lower than the resistance value of the resin layer 28 as the second resin layer, the same as described above. When the charging member and the image carrier are transported in contact with each other, even if charge is generated on the surface of the image carrier due to contact with the image carrier, the generated charge has a relatively low resistance value. Transition to layer 24. Therefore, charge accumulation on the surface of the image bearing member is suppressed, charging unevenness in the initial stage of use is suppressed, and image defects are prevented as compared with the conventional case.

Here, when a resin layer is formed between the base material 22 and the resin surface layer 24, the resistance value of the resin surface layer 24 is, for example, 10 ⁹ Ω / □ or more and 10 ¹² Ω / □ or less. The resistance value of the resin layer on the material 22 side or the resistance value of the resin adhesive layer 36 which is the first resin layer in contact with the base material 22 is, for example, 10 ¹³ Ω / □ or more, and the difference between the resistance values of both layers is 10 ^3. It is preferable that it is Ω / □ or more. On the other hand, as shown in FIGS. 5 and 6, when the resin surface layer 24 is directly formed on the substrate 22, the resistance value of the resin surface layer may be outside the range of the resistance value, that is, the conductive layer. Or any of an insulating layer may be sufficient. Here, the “conductive layer” in this embodiment refers to a layer of less than 10 ¹³ Ω / □, while the “insulating layer” refers to 10 ¹³ Ω / □ or more.

The resistance value is represented by surface resistivity. This surface resistivity is in accordance with JIS K6911 (1995) using a circular electrode shown in FIG. 20 (for example, HR probe of High Lester IP manufactured by Mitsubishi Yuka Co., Ltd.). The value obtained from a current value after 10 seconds after applying a voltage of 100V. FIG. 20 is a schematic plan view (a) and a schematic cross-sectional view (b) illustrating an example of a circular electrode. The circular electrode includes a first voltage application electrode A and a plate-like insulator B. The first voltage application electrode A has a columnar electrode portion C and a cylindrical ring electrode having an inner diameter larger than the outer diameter of the columnar electrode portion C and surrounding the columnar electrode portion C at regular intervals. Part D is provided. A test piece T is sandwiched between the cylindrical electrode part C and the ring-shaped electrode part D and the plate-like insulator B in the first voltage application electrode A, and the cylindrical electrode part C and the ring shape in the first voltage application electrode A. The current I (A) flowing when the voltage V (V) is applied between the electrode part D is measured, and the surface resistivity ρs (Ω / □) can be calculated by the following formula (1). Here, in the following formula (1), d (mm) indicates the outer diameter of the cylindrical electrode portion C, and D (mm) indicates the inner diameter of the ring-shaped electrode portion D.
Formula (1) ρs = π × (D + d) / (D−d) × (V / I)

  The base material made of the nonwoven fabric in the present embodiment is desired to have a strength that does not leave a part of the sheet member between the image carrier and the charging member when the sheet member is pulled out and removed. When the sheet member is mounted, the sheet member is often deformed and mounted in the process cartridge, so that flexibility is also required. Further, in order to prevent the sheet member from falling off due to the rotation of the image carrier during transportation vibration, friction with the charging member is necessary, and paper having a predetermined thickness is preferable. Examples of the paper include printing paper such as high-quality paper and coated paper, wrapping paper such as kraft paper, Rasha paper, and Kent paper, and conductive paper containing a conductive agent may be used.

<Resin surface layer>
In the present embodiment, the resin surface layer is made of a resin selected from the group consisting of polyolefin, fluororesin, silicone resin, polyurethane, polyester, acrylic copolymer, polyamide, polyimide, phenol resin, and polyacetal resin. The surface form such as the surface resistance and surface roughness of the resin surface layer is not limited.

[Polyolefin]
Examples of the polyolefin include polyethylene and polypropylene obtained by polymerizing ethylene and propylene, resins obtained by copolymerizing ethylene, propylene, and α-olefin, ethylene-vinyl acetate copolymer resins, chlorinated polyethylene, and olefin resins. Blend resin etc. are mentioned. Polyethylene is preferable regardless of low-pressure polymerization or high-pressure polymerization from the viewpoint of contamination of the photoreceptor such as bleed. Particularly, from the viewpoint of preventing scratches on the photoreceptor, low-density polyethylene that is flexible with low hardness and linear low-density. Polyethylene is more preferred. As the polyolefin, for example, “Mirason” (manufactured by Mitsui Chemicals) or “AS Clean Film” (manufactured by Achilles) subjected to conductive treatment is used.

  Further, when polyethylene is used as the polyolefin, low density polyethylene is most preferable, followed by medium density polyethylene and high density polyethylene in this order. Here, the low density polyethylene means a specific gravity of 0.91 or more and less than 0.93, and the medium density polyethylene means a specific gravity of 0.93 or more and less than 0.942, and is a high density polyethylene. Means a specific gravity of 0.942 or more.

  The film thickness of the resin surface layer made of polyolefin is flexible and is not particularly limited as long as it is not wrinkled when it is interposed between the charging member and the image carrier, and it is not cut when transported or pulled out. 1 μm or more and 500 μm or less are preferable, and 20 μm or more and 100 μm or less are more preferable.

[Fluorine resin or silicone resin]
When a fluororesin or silicone resin is used as the resin surface layer, examples of the fluororesin include polytetrafluoroethylene, polychlorotrifluoroethylene, tetrafluoroethylene-hexafluoropropylene copolymer, polyvinylidene fluoride, and polyvinyl fluoride. And copolymers such as tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer and tetrafluoroethylene / ethylene copolymer containing these. Examples of the silicone resin include resins containing organosilicone such as dimethyl silicone and methylphenyl silicone in the molecular chain, and further amino-modified, epoxy-modified, carboxyl-modified, carbinol-modified, methacryl-modified, phenol-modified, polyether. Modified or alkyl-modified single or composite modified silicone resins are also used. Since the fluororesin or silicone resin has a smaller coefficient of friction than other resins, it is excellent in the pullability of the sheet member.

  The film thickness of the resin surface layer made of fluororesin or silicone resin is flexible and is not particularly wrinkled when interposed between the charging member and the image carrier, and is not particularly limited if it is not cut when transported or pulled out. However, it is preferably 10 μm or more and 500 μm or less, and more preferably 20 μm or more and 100 μm or less.

[Polyurethane or polyester]
When polyurethane or polyester is used as the resin surface layer, examples of the polyurethane include ester-based, ether-based, and carbonate-based depending on the type of polyol as a raw material, but from the viewpoint of adhesiveness to a photoreceptor as an image carrier, Ester urethane is preferred. Polyurethane or polyester is superior to other resins in impact absorption, absorbs the impact between the unused image carrier and the charging member during transportation, and suppresses the formation of charging history on the image carrier.

  Typical examples of polyester include polyethylene terephthalate, polyethylene isophthalate, polyethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, poly (ethylene / 1,4-dimethylene / cyclohexane) terephthalate copolymer resin, and the like. Among these, polyethylene terephthalate, polybutylene terephthalate and the like are preferable.

  Moreover, you may use the acrylic copolymer of the said polyurethane or polyester as a polyurethane or polyester.

  The film thickness of the resin surface layer made of polyurethane or polyester is flexible and does not wrinkle easily when interposed between the charging member and the image carrier, and is not particularly limited as long as it is not cut during transportation or drawing. However, in the case of extrusion molding, 10 μm or more and 500 μm or less are preferable, and 20 μm or more and 100 μm or less are more preferable. In the case of transfer molding, it is preferable to form a film thickness of 10 μm or more and 200 μm or less, and in wet coating, the film thickness is 10 μm or more and 50 μm or less.

[Polyamide or polyimide]
When polyamide or polyimide is used as the resin surface layer, examples of the polyamide include copolymer nylon resins such as nylon 12, nylon 6, nylon 6-12, 610 nylon, and 11 nylon. In particular, a low hardness and flexible nylon resin is more preferable from the viewpoint of preventing scratches on the photoreceptor. In particular, since polyamide is easily positively charged, it is difficult for positive charge to be generated on the image carrier during transportation.

  Moreover, as a polyimide, an aromatic polyimide etc. are mentioned, for example.

  The film thickness of the resin surface layer made of polyamide or polyimide is flexible and does not wrinkle easily when interposed between the charging member and the image carrier, and is not particularly limited as long as it is not cut during transportation or drawing. Is preferably 10 μm or more and 500 μm or less, more preferably 20 μm or more and 100 μm or less.

[Phenolic resin or polyacetal]
When a phenol resin or polyacetal is used as the resin surface layer, the resol type or novolac type is not limited as phenol. Also, an alkyl-modified phenol resin may be used. Since it can be handled in a liquid state, the phenol layer is preferably formed by coating on a substrate. As the polyacetal, a homopolymer having an oxymethylene unit structure, an oxyethylene copolymer, and a terminal treatment are not particularly limited. Examples of commercial products are Delrin (DuPont) and Duracon (Polyplastics). In particular, polyacetal is excellent in the pullability of the sheet member because the coefficient of friction is small next to the above-described fluororesin and silicone resin.

  The film thickness of the resin surface layer made of phenol resin or polyacetal is flexible, and it is difficult to wrinkle when interposed between the charging member and the image carrier. However, the film thickness of the resin surface layer made of polyacetal is preferably 10 μm or more and 500 μm or less, more preferably 20 μm or more and 100 μm or less, while the resin surface layer made of phenol resin whose film is harder than that made of polyacetal. The film thickness is preferably 10 μm or more and 100 μm or less.

[Image carrier]
As an example of the image carrier in the present embodiment, an electrophotographic photosensitive member will be described below as an example.

  FIGS. 13 to 16 are schematic cross-sectional views showing a preferred embodiment of the electrophotographic photosensitive member according to the present embodiment, in which the electrophotographic photosensitive member 11 is perpendicular to the stacking direction of the substrate 12 and the photosensitive layer 13. It is cut by a flat plane. Each of the electrophotographic photoreceptors 11 shown in FIGS. 13 to 16 is a function-separated photoreceptor, and the charge generation layer 15 and the charge transport layer 16 are separately provided on the photosensitive layer 13 provided in each photoreceptor. Yes.

  More specifically, in the electrophotographic photoreceptor 11 shown in FIG. 13, 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. 15, 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 illustrated electrophotographic photoreceptor 11, 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. 16, 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. Although not described here, this 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. It is possible.

  Hereinafter, each component of the electrophotographic photoreceptor 11 will be described in detail.

  As the conductive substrate 12, a metal sheet such as aluminum, copper, iron, zinc, or nickel; aluminum, copper, gold, silver, platinum, palladium, titanium, nickel-chromium on a substrate such as paper, plastic, or glass; Deposited metal such as stainless steel and copper-indium; Deposited conductive metal compound such as indium oxide and tin oxide on the base; Laminated metal foil on the base; Carbon black, indium oxide, oxidized Examples include tin-antimony oxide powder, metal powder, copper iodide and the like 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 in advance by a surface treatment. Is also possible. Such roughening can prevent grain-like density spots due to interference light that can be generated inside the photosensitive member when a coherent light source such as a laser beam is used as the exposure light source. 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.

  The undercoat layer 14 includes vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris-2-methoxyethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxy. Propyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-2-aminoethylaminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, β It can be used by containing a silane coupling agent such as -3,4-epoxycyclohexyltrimethoxysilane. 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- Known binder resins such as a vinyl acetate copolymer, an epoxy resin, polyvinyl pyrrolidone, polyvinyl pyridine, polyurethane, polyglutamic acid, and polyacrylic acid can also be used. These mixing ratios can be appropriately set as necessary.

  In the present embodiment, the undercoat layer 14 may contain metal oxide fine particles. The metal oxide fine particles can be arbitrarily selected from known metal oxides as long as the desired electrophotographic photoreceptor characteristics can be obtained, but one or more metals selected from tin oxide, titanium oxide, and zinc oxide Oxide fine particles are preferably used. The metal oxide fine particles are more preferably coated with at least one coupling agent, and the coupling agent is more preferably a silane coupling agent.

  Further, an electron transporting pigment can 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 can also be formed by containing fine metal oxide particles provided with an acceptor compound. As the acceptor compound, any compound can be used as long as the desired properties 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 can be preferably used. More specifically, anthraquinone, alizarin, quinizarin, anthralphine, pullpurin and the like are particularly preferably used.

  The amount of these acceptor compounds to be applied can be arbitrarily set as long as desired properties are obtained, but it is preferably applied in an amount of 0.01% by mass to 20% by mass with respect to the metal oxide. More preferably, it is provided at 0.05% by mass or more and 10% by mass or less with respect to the metal oxide. If it is less than 0.01% by mass, sufficient acceptor property that contributes to improvement of charge accumulation in the undercoat layer cannot be imparted, so that it is likely to cause deterioration in sustainability such as increase in residual potential during repeated use. In addition, when the amount exceeds 20% by mass, the metal oxides tend to agglomerate with each other. Therefore, when the undercoat layer is formed, the metal oxide cannot form a good conductive path in the undercoat layer. Not only does it easily deteriorate the sustainability such as an increase in residual potential, but it also easily causes image quality defects such as black spots.

  As a method for applying an acceptor compound to metal oxide fine particles, an acceptor compound dissolved in an organic solvent is dropped and sprayed with dry air or nitrogen gas while stirring the metal oxide fine particles with a mixer having a large shearing force. Is uniformly applied. The addition or spraying is preferably performed at a temperature lower than the boiling point of the solvent. When spraying at a temperature higher than the boiling point of the solvent, the solvent evaporates before stirring uniformly, and the acceptor compound is locally concentrated. Therefore, it is not preferable because there is a defect that uniform processing is difficult. After addition or spraying, drying can be performed at a temperature higher than the boiling point of the solvent. In addition, metal oxide fine 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. Then, it is uniformly applied by removing the solvent. Moreover, the solvent removal method is distilled off by filtration, distillation, or heat drying.

As the metal oxide fine particles to which the acceptor compound is provided, a powder resistance of about 10 ² Ω · cm or more and 10 ¹¹ Ω · cm or less is required. This is because the undercoat layer 14 needs to obtain an appropriate resistance for obtaining leak resistance.

  The undercoat layer 14 is formed by applying a coating solution obtained by mixing / dispersing the above materials in a predetermined 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 organic metal 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 can be used alone or in admixture of two or more. The coating solution is dried at a temperature at which the solvent can be evaporated and a film can be formed. 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 fine particles are not contained. It is more preferable. Moreover, when it contains metal oxide microparticles | fine-particles, it is preferable to exceed 15 micrometers, and it is more preferable that they are 15 micrometers or more and 50 micrometers or less. When the thickness of the undercoat layer 14 satisfies the above conditions, local dielectric breakdown (photoreceptor leakage) in the electrophotographic photoreceptor can be more reliably prevented. In addition, stable characteristics can be obtained even in long-term continuous use.

  As the material used for the intermediate layer 18, similarly to the material used for the undercoat layer 14, an organic zirconium compound such as a zirconium chelate compound, a zirconium alkoxide compound, and a zirconium coupling agent; a titanium chelate compound, a titanium alkoxide compound, and a titanate. Organic titanium compounds such as coupling agents; organoaluminum compounds such as aluminum chelate compounds and aluminum coupling agents; antimony alkoxide compounds; germanium alkoxide compounds; organic indium compounds such as indium alkoxide compounds and indium chelate compounds; manganese alkoxide compounds and manganese chelates Organic manganese compounds such as compounds; Organotin compounds such as tin alkoxide compounds and tin chelate compounds; Aluminum silicon Alkoxide compounds; aluminum titanium alkoxide compound; 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, as in the case of the undercoat layer 14, the intermediate layer 18 is made of vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris-2-methoxyethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyl. Trimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-2-aminoethylaminopropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ -A silane coupling agent such as ureidopropyltriethoxysilane or β-3,4-epoxycyclohexyltrimethoxysilane can be contained and used. 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- Known binder resins such as a vinyl acetate copolymer, an epoxy resin, polyvinyl pyrrolidone, polyvinyl pyridine, polyurethane, polyglutamic acid, and polyacrylic acid can also be used. These mixing ratios can be appropriately set as necessary.

  Further, in the intermediate layer 18, similarly to the undercoat layer 14, an electron transporting pigment can be mixed / dispersed and used. 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 intermediate layer is lowered and a coating film defect is caused.

  As in the case of the undercoat layer 14, the intermediate layer 18 is formed by applying a coating liquid obtained by mixing / dispersing the above materials in a predetermined 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 organic metal 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 can be used alone or in admixture of two or more. The coating solution is dried at a temperature at which the solvent can be evaporated and a film can be formed. The thickness of the intermediate layer 18 thus obtained is preferably 0.1 μm or more and 10 μm or less, and more preferably 0.5 μm or more and 5 μm or less. When the film thickness of the intermediate layer 18 satisfies the above conditions, stable characteristics can be obtained even when the electrophotographic photosensitive member is used continuously for a long time.

  The charge generation layer 15 preferably contains a hydroxygallium phthalocyanine pigment. As the hydroxygallium phthalocyanine used in the present embodiment formed using the coating solution for forming the charge generation layer, any hydroxygallium phthalocyanine capable of obtaining desired characteristics can be used, but particularly for CuKα characteristic X-rays. Those having diffraction peaks at 7.5 ° and 28.3 ° of the Bragg angle (2θ ± 0.2 °) are preferably used.

  The hydroxygallium phthalocyanine pigment is dispersed and held in a predetermined binder resin to form the charge generation layer 15. Such a binder resin can be 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 can be used alone or in combination of two or more. The blending ratio (mass ratio) of the charge generating material and the binder resin is preferably in the range of 10: 1 to 1:10, and more preferably in the range of 8: 2 to 3: 7.

  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 a predetermined 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, etc. Can be 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 can be 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.

  As long as the position of the absorption peak and the intensity ratio are maintained within a predetermined range, the hydroxygallium phthalocyanine dispersion in the present embodiment may be subjected to a surface treatment on the hydroxygallium phthalocyanine pigment in order to improve dispersibility. Is possible. A coupling agent or the like can be used as the surface treatment agent, but is not limited thereto. As coupling agents, vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane , Vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ- Examples include silane coupling agents such as aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, and γ-chloropropyltrimethoxysilane. Among these, vinyltriethoxysilane, vinyltris (2-methoxyethoxysilane), 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxy Silane, N-2- (aminoethyl) -3-aminopropyltrimethoxysilane, N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3- Aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-chloropropyltrimethoxysilane are preferred.

  In addition to coupling agents, zirconium butoxide, zirconium zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl acetoacetate butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octoate Organic zirconium compounds such as zirconium naphthenate, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, and isostearate zirconium butoxide may be blended. Tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt, titanium lactate, titanium lactate Organic titanium compounds such as ethyl ester, titanium triethanolamate, polyhydroxy titanium stearate, aluminum isopropylate, monobutoxy aluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate) An organoaluminum compound such as can also be used.

  Further, the coating solution for charge generation layer can be subjected to centrifugal separation treatment after dispersion. By the centrifugal separation process, it is possible to efficiently remove the dispersion container and the wear pieces of the dispersion medium and coarse particles with poor dispersion mixed during dispersion of the coating liquid.

  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. Can be obtained. Here, as a solvent used for the coating liquid of the charge generation layer 1, specifically, methanol, ethanol, n-butanol, benzyl alcohol, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran , Methylene chloride, chloroform, toluene, xylene, chlorobenzene, dimethylformamide, dimethylacetamide, water, and the like. One of these may be used alone, or a mixture of two or more may be used.

  The film thickness of the charge generation layer 15 thus obtained is preferably 0.05 μm or more and 5 μm or less, and preferably 0.1 μm or more and 1 μm or less in order to give good electrical characteristics and image quality. More preferred. If the thickness of the charge generation layer 15 is less than 0.05 μm, sufficient sensitivity cannot be given. On the other hand, when the thickness of the charge generation layer 15 exceeds 5 μm, it is easy to cause adverse effects such as poor charging properties.

  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 can also be used. Furthermore, a polymer having a group composed of the above compound in the main chain or side chain can also be used. These charge transport materials can be used alone or in combination of two or more.

  The binder resin for the charge transport layer 16 is preferably a resin capable of forming an electrically insulating film. Examples of such resins 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, chloride Vinylidene-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 Vinylidene polymer wax chloride, polyurethane, and the like. These binder resins can be used individually by 1 type or in mixture of 2 or more types. The mixing ratio (mass ratio) between the binder resin and the charge transport material can be arbitrarily set in any case, but attention must be paid 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 can be arbitrarily 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 for. Moreover, these can be used individually by 1 type or in mixture of 2 or more types. The thickness of the charge transport layer 16 is preferably 5 μm or more and 60 μm or less, more preferably 10 μm or more and 50 μm or less. In the present embodiment, if it is 30 μm or more, density unevenness due to vibration tends to occur strongly, so that it can be particularly preferably applied.

  In the charge transport layer 16, additives such as an antioxidant and a light stabilizer are added to the photosensitive layer for the purpose of preventing deterioration of the photoreceptor due to ozone, oxidizing gas, or light / heat generated in the image forming apparatus. Can be added.

  Examples of the antioxidant include hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroidanone and derivatives thereof, organic sulfur compounds, and organic phosphorus compounds.

  Examples of phenolic antioxidants include 2,6-di-t-butyl-4-methylphenol, styrenated phenol, n-octadecyl-3- (3 ′, 5′-di-t-butyl-4′-hydroxy Phenyl) -propionate, 2,2′-methylene-bis- (4-methyl-6-tert-butylphenol), 2-t-butyl-6- (3′-tert-butyl-5′-methyl-2′-) Hydroxybenzyl) -4-methylphenyl acrylate, 4,4′-butylidene-bis- (3-methyl-6-tert-butylphenol), 4,4′-thio-bis- (3-methyl-6-tert-butylphenol) ), 1,3,5-tris (4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, tetrakis- [methylene-3- (3 ′, 5 ′,-di-t-butyl) 4′-hydroxyphenyl) propionate] methane, 3,9-bis [2- [3- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy] -1,1-dimethylethyl] -2 4,8,10-tetraoxaspiro [5,5] undecane and the like.

  Examples of hindered amine compounds include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1- [2- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy]- 2,2,6,6-tetramethylpiperidine, 8-benzyl-7,7,9,9-tetramethyl-3-octyl-1,3,8-triazaspiro [4,5] undecane-2,4-dione 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine succinate Polycondensate, poly [{6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diimyl} {(2,2,6,6-tetra Methyl-4-piperidyl) imino} hexamethylene {(2,3,6,6-tetramethyl-4-piperidyl) imino}], 2- (3,5-di-t-butyl-4-hydroxybenzyl)- 2-n-butylmalonate bis (1,2,2,6,6-pentamethyl-4-piperidyl), N, N′-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl- N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate and the like.

  Examples of organic sulfur antioxidants include dilauryl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, pentaerythritol-tetrakis. -(Β-laurylthiopropionate), ditridecyl-3,3′-thiodipropionate, 2-mercaptobenzimidazole and the like.

  Examples of the organophosphorus antioxidant include trisnonylphenyl phosfte, triphenyl phosfte, tris (2,4-di-t-butylphenyl) -phosfte, and the like.

The organic sulfur-based and organic phosphorus-based antioxidants are called secondary antioxidants, and a synergistic effect can be obtained by using them together with a primary antioxidant such as a phenol-based or amine-based antioxidant.
Examples of the light stabilizer include benzophenone, benzotriazole, dithiocarbamate, and tetramethylpiperidine derivatives.

  Examples of the benzophenone light stabilizer include 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, and the like.

  Examples of the benzotriazole light stabilizer include 2- (2′-hydroxy-5′-methylphenyl) -benzotriazole, 2- [2′-hydroxy-3 ′-(3 ″, 4 ″, 5 ′, 6 ″). -Tetrahydrophthalimido-methyl) -5'-methylphenyl] benzotriazole, 2- (2'-hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'- Hydroxy-3′-t-butyl-5′-methylphenyl) -5-chlorobenzotriazole, 2- (2′-hydroxy-3 ′, 5 ′,-di-t-butylphenyl) benzotriazole, 2- ( 2'-hydroxy-5'-t-octylphenyl) benzotriazole, 2- (2'-hydroxy-3 ', 5',-di-t-amylphenyl) benzotriazole And the like.

Other compounds include 2,4-di-t-butylphenyl-3 ′, 5′-di-t-butyl-4′-hydroxybenzoate, nickel dibutyl-dithiocarbamate, and the like.
Further, at least one kind of electron accepting substance can be included for the purpose of improving sensitivity, reducing residual potential, reducing fatigue during repeated use, and the like. 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.

  In addition, a solid lubricant or a metal oxide can be dispersed in the charge transport layer 16 for the purpose of reducing wear. 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, tin oxide and the like. When the solid lubricant is dispersed, the friction coefficient on the surface of the charge transport layer decreases, so that wear can be suppressed. Further, when the metal oxide is dispersed, the mechanical hardness of the charge transport layer is increased, so that wear can be suppressed. Further, since the fluorine-containing resin particles are hardly dispersed particles, dispersibility is improved by using a fluorine-containing polymer-based dispersion aid. As a method for dispersing the solid lubricant and metal oxide, methods such as a roll mill, a ball mill, a vibration ball mill, an attritor, a sand mill, a colloid mill, a paint shaker, a homogenizer, and a high-pressure treatment type homogenizer can be used. In this dispersion, it is effective to make the dispersed particles 1.0 μm or less, preferably 0.5 μm or less.

  Further, a trace amount of silicone oil can be added as a leveling agent for improving the smoothness of the coating film.

As shown in FIG. 15, a protective layer 17 can be formed on the electrophotographic photosensitive member according to the present embodiment as necessary. As the surface protective layer 17, a cured film formed by including a compound represented by the following general formula (I) is preferable.
F- [DA] b (I)

In the general formula (I), F represents an organic group derived from a photofunctional compound, D represents a divalent group, and A represents a water represented by -SiR ¹ _3-a (OR ² ) _a. The substituted silicon group which has a decomposable group is represented, b represents the integer of 1-4. 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. be able to. 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 to} Ar ⁴ each independently represents a substituted or unsubstituted aryl group. Ar ⁵ represents a substituted or unsubstituted aryl group or an arylene group. B pieces out of Ar ^{1 to} Ar ⁴ are bonded to a group represented by —D—SiR ¹ _3-a (OR ² ) _a . k represents 0 or 1;

Ar ^{1 to} 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, a phenyl group substituted with an alkyl group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms, or an unsubstituted phenyl group, carbon represents one selected from the group consisting of an aralkyl group having 7 to ^10, each of R 7 to R ⁹ hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms or carbon atoms, 1 Represents one selected from the group consisting of a phenyl group substituted by an alkoxy group of -4 or an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, and a halogen atom, and Ar represents a substituted or unsubstituted arylene group X represents —D—SiR ¹ _3-a (OR ² ) _a in formula (I), m and s each represent 0 or 1, and t represents an integer of 1 to 3, respectively.

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, or unsubstituted. 1 group selected from the group consisting of a 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)-(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 unsubstituted. 1 represents a group selected from the group consisting of a phenyl group, an aralkyl group having 7 to 10 carbon atoms, and a halogen atom, W represents a divalent group, q and r each represents an integer of 1 to 10, and t represents Each represents an integer of 1 to 3.

W in the above 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 to 3.

In general formula (II), Ar ₅ is an aryl group exemplified in the description of Ar _{1 to} Ar ₄ when k is 0, and when k is 1, a predetermined hydrogen atom is taken from the aryl group. Excluded arylene 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 a three-dimensional inorganic glassy network, On the other hand, it imparts moderate flexibility to an inorganic glassy network that is brittle and plays a role of improving the toughness of the film. 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 1~15), - COO -, - S -, - O -, - CH 2 -C 6 H 4 -, - n = CH -, - C 6 H 4 -C 6 H 4 -, A combination of these, or 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 the general formula (I) has two or more Si atoms, which facilitates formation of an inorganic glassy network and improves mechanical strength. Tend to.

  The compound represented by general formula (I) may be used individually by 1 type, and may be used together 2 or more types.

A compound represented by the following general formula (III) may be used in combination with the compound represented by the general formula (I) for the purpose of further improving the mechanical strength of the cured film.
B-An (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. When the compound represented by the general formula (III) and the compound represented by the general formula (I) are used in combination, the crosslinked structure of the cured film tends to be three-dimensional, and the cured film has an appropriate flexibility. Therefore, stronger mechanical strength can be obtained. Preferred examples of the compound represented by the general formula (III) are shown in Table 1.

  In addition to the compound represented by the general formula (I), another compound capable of crosslinking reaction may be used in combination. As such a compound, various silane coupling agents and commercially available silicone hard coat agents can be 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 can be added to the protective layer 17 for the purpose of imparting surface lubricity. By improving the surface lubricity, the coefficient of friction with the cleaning member decreases, and the wear resistance can be improved. It also has an effect of preventing adhesion of discharge products, toner, paper dust, and the like to the surface of the photoconductor, which helps to improve the life of the photoconductor.

  As the fluorine-containing compound, a fluorine atom-containing polymer such as polytetrafluoroethylene can be added as it is, or fine particles of these polymers can be added. In the case of a cured film formed of the compound represented by the general formula (I), it is desirable to add a fluorine-containing compound that can react with an alkoxysilane and configure it as a part of the crosslinked film. Examples of such fluorine-containing compounds include (tridecafluoro-1,1,2,2-tetrahydrooctyl) triethoxysilane, (3,3,3-trifluoropropyl) trimethoxysilane, 3- (heptafluoro Isopropoxy) propyltriethoxysilane, 1H, 1H, 2H, 2H-perfluoroalkyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorooctyltri An ethoxysilane etc. are mentioned.

  The content of the fluorine-containing compound is preferably 20% by mass or less based on the total amount of the protective layer 17. When the content of the fluorine-containing compound exceeds 20% by mass, a problem may occur in the film formability of the crosslinked cured film.

  Although the protective layer 17 containing the above compound has sufficient oxidation resistance, an antioxidant may be added for the purpose of imparting stronger oxidation resistance. Antioxidants are preferably hindered phenols or hindered amines, organic sulfur antioxidants, phosphite antioxidants, dithiocarbamate antioxidants, thiourea antioxidants, benzimidazole antioxidants. , Etc., 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.

  Examples of the hindered phenol antioxidant include 2,6-di-t-butyl-4-methylphenol, 2,5-di-t-butylhydroquinone, N, N′-hexamethylene bis (3,5-di). -T-butyl-4-hydroxyhydrocinnamide, 3,5-di-t-butyl-4-hydroxybenzylphosphonate-diethyl ester, 2,4-bis [(octylthio) methyl] -o-cresol, 2 , 6-di-t-butyl-4-ethylphenol, 2,2'-methylenebis (4-methyl-6-t-butylphenol), 2,2'-methylenebis (4-ethyl-6-t-butylphenol), 4,4′-butylidenebis (3-methyl-6-tert-butylphenol), 2,5-di-tert-amylhydroquinone, 2-tert-butyl-6- (3-butyl-2-hydroxy) Proxy-5-methylbenzyl) -4-methylphenyl acrylate, 4,4'-butylidene bis (3-methyl -6-t-butylphenol) and the like.

  In addition, other additives used for forming a known coating film can be added to the protective layer 17, and known materials such as a leveling agent, an ultraviolet absorber, a light stabilizer, and a surfactant are used. be able to.

  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 by general formula (I) raise | generate a crosslinking hardening reaction three-dimensionally, and a firm 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 to 200 ° C, more preferably 100 ° C to 160 ° C.

  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, it can 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 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.

[Image forming apparatus]
FIG. 9 is a cross-sectional view schematically showing the basic configuration of the image forming apparatus according to the first embodiment of the present invention. An image forming apparatus 200 shown in FIG. 9 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.

  A charging device 208 in FIG. 9 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). A charging device is used.

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

  The transfer device 212 is capable of supplying a current having a predetermined current density toward 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, brush cleaning, roll cleaning, and the like can be 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 according to the present embodiment may further include a light irradiation device as the static eliminator 214 as shown in FIG. As a result, when the electrophotographic photosensitive member is repeatedly used, the phenomenon that the residual potential of the electrophotographic photosensitive member is brought into the next cycle is prevented, so that the image quality can be further improved.

  FIG. 10 is a sectional view schematically showing a basic configuration of an image forming apparatus according to the second embodiment of the present invention. The image forming apparatus 210 shown in FIG. 10 transfers the toner image formed on the electrophotographic photosensitive member 207 to the primary transfer member 212a and then supplies it between the primary transfer member 212a and the secondary transfer member 212b. A transfer device of an intermediate transfer system for transferring to a transfer target (image output medium) 500 to be transferred, 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. Can be supplied. Although not shown in FIG. 10, the image forming apparatus 210 may further include a static eliminator as in the image forming apparatus 200 shown in FIG. Other configurations of the image forming apparatus 210 are the same as those of the image forming apparatus 200.

  As described above, in the image forming apparatus 210, the intermediate transfer method is applied. However, as in the case of the image forming apparatus 200 according to the first embodiment, the electrophotographic photosensitive member 207, the charging device, and the like. In combination, it is possible to stably obtain good image quality over a long period of time.

  Further, when the toner image formed on the electrophotographic photosensitive member 207 is transferred to the primary transfer member 212a, a current having a predetermined current density is supplied from the primary transfer member 212a to the electrophotographic photosensitive member 207. Thus, fluctuations in the transfer current due to the type and material of the transfer medium 500 can be suppressed, so that the amount of charge flowing into the electrophotographic photoreceptor 207 can be accurately controlled. As a result, it is possible to achieve higher image quality and reduced environmental burden at a higher level.

  FIG. 11 is a cross-sectional view schematically showing a basic configuration of an image forming apparatus according to the third embodiment of the present invention. An image forming apparatus 220 shown in FIG. 11 is an intermediate transfer type image forming apparatus. In the housing 400, four electrophotographic photoreceptors 401a to 401d (for example, the electrophotographic photoreceptor 401a is yellow and the electrophotographic photoreceptor 401b is magenta). The electrophotographic photosensitive member 401c can form an image of cyan and the electrophotographic photosensitive member 401d can form a black color) are arranged in parallel along the intermediate transfer belt 409.

  Each of the electrophotographic photosensitive members 401a to 401d can be rotated in a predetermined direction (counterclockwise on the paper surface), and the charging rolls 402a to 402d, the developing devices 404a to 404d, and the primary transfer roll 410a along the rotation direction. To 410d and cleaning blades 415a to 415d are arranged. Each of the developing devices 404a to 404d can supply toners of four colors, yellow, magenta, cyan, and black, which are accommodated in toner cartridges 405a to 405d. These toners satisfy the condition that the average shape factor is 100 to 140. Further, the primary transfer rolls 410a to 410d are in contact with the electrophotographic photosensitive members 401a to 401d via the intermediate transfer belt 409, respectively.

  Further, a laser light source (exposure device) 403 is disposed at a predetermined position in the housing 400, and the surface of the electrophotographic photoreceptors 401a to 401d after charging is irradiated with laser light emitted from the laser light source 403. Is possible. Accordingly, charging, exposure, development, primary transfer, and cleaning are sequentially performed in the rotation process of the electrophotographic photosensitive members 401a to 401d, and the toner images of the respective colors are transferred onto the intermediate transfer belt 409 in an overlapping manner. Here, by combining the electrophotographic photoconductors 401a to 401d with each color toner having an average shape factor of 100 to 140, even in a tandem color image forming apparatus, high image quality and a reduction in environmental burden can be achieved. It can be achieved at a standard level.

  The intermediate transfer belt 409 is supported with a predetermined tension by a drive roll 406, a support roll 408, and a tension applying roll 407, and can rotate without causing deflection due to the rotation of these rolls. Further, the secondary transfer roll 413 is disposed so as to contact the support roll 408 via the intermediate transfer belt 409. The intermediate transfer belt 409 that has passed between the support roll 408 and the secondary transfer roll 413 is cleaned by, for example, a cleaning blade 416 disposed in the vicinity of the drive roll 406 and then repeatedly used for the next image forming process. Is done.

  A tray (transfer medium tray) 411 is provided at a predetermined position in the housing 400, and the transfer medium 500 such as paper in the tray 411 is transferred to the intermediate transfer belt 409 and the secondary transfer roll by the transfer roll 412. Then, the paper is sequentially transferred between the two fixing rolls 414 that are in contact with each other and the two fixing rolls 414, and then discharged to the outside of the housing 400.

  In the above description, the case where the intermediate transfer belt 409 is used as the intermediate transfer member has been described. However, the intermediate transfer member may have a belt shape like the intermediate transfer belt 409 or a drum shape. There may be.

  When a drum-shaped configuration is adopted as the intermediate transfer member, it is preferable to use a cylindrical substrate formed of aluminum, stainless steel (SUS), copper, or the like as the substrate. If necessary, an elastic layer can be coated on the cylindrical substrate, and a surface layer can be formed on the elastic layer.

  The process cartridge according to the present embodiment includes a developing device and an image carrier in addition to an image carrier made of a photosensitive member, a charging member, and a sheet member interposed between the image carrier and the charging member. It is a preferable aspect that these cleaning devices are combined and integrated by a mounting member. The case needs to be provided with an opening for exposure.

  FIG. 12 is a sectional view schematically showing a preferred embodiment of the process cartridge of the present invention. In addition to the electrophotographic photosensitive member 207, the process cartridge 300 is provided with 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 developing device 211 supplies toner to the electrophotographic photosensitive member 207.

  The process cartridge 300 is detachably attached to an image forming apparatus main body including a transfer device 212, a fixing device 215, and other components (not shown), and the image forming apparatus together with the image forming apparatus main body. It constitutes.

  Next, FIGS. 17 and 18 illustrate a configuration in which a sheet member is interposed between an unused image carrier and a charging member. In FIG. 17 and FIG. 18, the configuration other than the electrophotographic photosensitive member 207 that is an image carrier and the charging device 208 that is a charging member is omitted.

  As shown in FIG. 17, the sheet member 20 is inserted so that the resin surface layer exists between the electrophotographic photoreceptor 207 and the charging device 208, and one end side of the base material corresponding to the drawing direction of the sheet member 20 Is transferred to the electrophotographic photosensitive member 207 so as to protrude from the opening 102 of the case 100 of the process cartridge, and on the other end side of the base member of the sheet member is folded back to the charging member 208 side. It is preferable that the part 60 is provided. The folded portion 60 prevents the sheet member 20 from dropping from between the electrophotographic photosensitive member 207 and the charging device 208 during unused conveyance. Here, the sheet member 20 has been described as an example. However, the present invention is not limited to this, and the above-described sheet members 30, 40, and 50 are similarly mounted. 1 to 8, the resin surface layer 22 is provided at the end portion of the base material 22. However, the present invention is not limited to this, and when the folded portion 60 is made of only the base material 22, the sheet member is used. It is preferable to appropriately select the formation position of the resin surface layer 24 with respect to the base material 22 according to the mounting of the base material 22.

  As shown in FIG. 18, in the case of a process cartridge having a cleaning roll 205 that adheres to the charging device 208 and cleans the surface, a resin surface layer exists between the electrophotographic photosensitive member 207 and the charging device 208. Thus, the sheet member 20 is inserted, and one end side of the base material corresponding to the drawing direction of the sheet member 20 is passed to the electrophotographic photoreceptor 207 so as to protrude from the opening 112 of the case 110 of the process cartridge. On the other hand, the other end side of the base material of the sheet member is passed to the charging device 208 and further inserted and mounted between the charging device 208 and the cleaning roll 205. By inserting the other end of the base material of the sheet member 20 between the charging device 208 and the cleaning roll 205, the sheet member 20 is dropped from between the electrophotographic photosensitive member 207 and the charging device 208 during unused conveyance. Is suppressed. Here, the sheet member 20 has been described as an example. However, the present invention is not limited to this, and the above-described sheet members 30, 40, and 50 are similarly mounted. 1 to 8, the resin surface layer 22 is provided at the end of the base material 22, but the present invention is not limited to this, and a portion inserted between the charging device 208 and the cleaning roll 205 is a base. When only the material 22 is formed, it is preferable to appropriately select the formation position of the resin surface layer 24 with respect to the base material 22 in accordance with the mounting of the sheet member.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples. In the examples, “part” represents “part by mass”.

  First, the degree of the coefficient of friction of the resin used for the resin surface layer of the sheet member was evaluated using the apparatus shown in FIG. When a resin sheet having a length of 200 mm, a width of 350 mm and a thickness of 60 μm is sandwiched between the charging roll shown in FIG. 19 and the photosensitive member, and then the resin sheet is pulled out at a constant speed of 50 cm / s, the charging is actually performed. The maximum drive torque required to drive the roll was measured. Here, the smaller the maximum driving torque, the smaller the friction coefficient of the resin. Table 2 shows the results.

In Table 2, “Nitoflon Film No. 900UL” (manufactured by Nitto Denko) is used as the fluororesin, “Silicon Film” (manufactured by ASONE) is used as the silicone resin, and “Delrin 900P” (manufactured by DuPont) as the polyacetal. , “Alamine CM8000” (manufactured by Toray Industries, Inc.) as the polyamide, “Mirason 27” (manufactured by Mitsui Chemicals), a low-density polyethylene as the polyolefin, and “Cranziel U-1490” (manufactured by Kurabo Industries) as the polyurethane. "Tetron film GE" (manufactured by Teijin DuPont Films) is used as the polyester, "Kapton 100H" (manufactured by Toray DuPont) is used as the polyimide, and "Sumilite Resin PR50209" (manufactured by Sumitomo Bakelite) is used as the phenol resin. Was used.

-Production of photoconductor A-
On a 30 mmφ cylindrical Al substrate subjected to a honing treatment, 100 parts of a zirconium compound (trade name: Orgatics ZC540, manufactured by Matsumoto Pharmaceutical), 10 parts of a silane compound (trade name: A1100, manufactured by Nihon Unicar), 400 parts of isopropanol And a solution containing 200 parts of butanol were dip-coated and dried by heating at 150 ° C. for 10 minutes to form an undercoat layer of 0.1 μm.

  On this aluminum substrate, the Bragg angles (2θ ± 0.2 °) in the X-ray diffraction spectrum are 7.5 °, 9.9 °, 12.5 °, 16.3 °, 18.6 °, 25. 10 parts of hydroxygallium phthalocyanine having a strong diffraction peak at 1 ° and 28.3 ° are mixed with 10 parts of polyvinyl butyral (trade name: S-REC BM-S, manufactured by Sekisui Chemical Co., Ltd.) and 1000 parts of n-butyl acetate, After being dispersed with a glass shaker and a glass shaker for 1 hour, the resulting coating solution was dip-coated on the undercoat layer and dried by heating at 100 ° for 10 minutes to form a charge generation layer having a thickness of 0.15 μm. Formed. This is referred to as a photoreceptor A.

  Next, 40 parts by weight of N, N′-bis (3-methylphenyl) -N, N′-diphenylbenzidine, 60 parts by weight of bisphenol Z polycarbonate resin (viscosity average molecular weight 40,000), silica oil surface-treated silica “ 10 parts by mass of “RY50” (manufactured by Nippon Aerosil Co., Ltd.) and 280 parts by mass of Tetrohydrofuran and 120 parts by mass of toluene were sufficiently dissolved and mixed, and then further mixed. At this time, the room temperature was set to 25 ° C., and the liquid temperature in the mixing step was kept at 25 ° C. Then, it disperse | distributed with the sand grinder using a glass bead, and the silicone oil surface treatment silica dispersion liquid was created. At this time, 24 ° C. water was allowed to flow through the vessel of the sand cylinder, and the temperature of the dispersion was maintained at 50 ° C.

  The obtained coating solution was dip-coated on the charge generation layer in the same manner as the charge generation layer to form a 34 μm charge transport layer at 130 ° C. for 40 minutes.

-Production of charging roll A-
<Formation of elastic layer>
As the metal core, a SUM roll having a diameter of 8 mm was subjected to electroless nickel plating. The following mixture is kneaded with an open roll, and a semiconductive elastic layer is formed around the plated metal core so as to have a rubber thickness of 3 mm, and then 10 points average with a thickness of 2 mm by plunge polishing. The surface was finished so that the surface roughness Rz was 1 μm or more and 5 μm or less to form a semiconductive elastic layer.

・ Rubber material 100 parts by mass (epichlorohydrin-ethylene oxide-allyl glycidyl ether copolymer rubber: Gechron 3106: 95%, acrylonitrile butadiene rubber: Nipol 1312: 5%: manufactured by Zeon Corporation)
・ Carbon black (# 3030B: manufactured by Mitsubishi Carbon Black) 15 parts by mass ・ Ion conductive agent 1 part by mass (benzyltriethylammonium chloride: manufactured by Kanto Chemical Co., Inc.)
・ Vulcanizing agent ((sulfur) 200 mesh: manufactured by Tsurumi Chemical Co., Ltd.) 1 part by mass ・ Vulcanization accelerator (Noxeller DM: manufactured by Ouchi Shinsei Chemical Co., Ltd.) 2.0 parts by mass ・ Vulcanizing accelerator (Noxeller TT) : Ouchi Shinsei Chemical Industry Co., Ltd.) 0.5 parts by mass, zinc oxide (Zinc Hana No. 1: made by Shodo Chemical Industry Co., Ltd.) 5 parts by mass, calcium carbonate (Whiteon SSB: Shiraishi Calcium) 30 parts by mass

<Formation of outermost layer>
Dispersion A obtained by dispersing the following mixture with a bead mill was diluted with methyl ethyl ketone and dip-coated on the end side surface of the semiconductive elastic layer. On the other hand, the total mass of dispersion A and roughening filler The dispersion B, to which 30 parts by mass of a porous nylon resin manufactured by Arkema Inc. with a diameter of 10 μm was added, was diluted with methyl ethyl ketone and dip-coated on the side surface near the center of the semiconductive elastic layer. Heating and drying for 30 minutes to form an outermost layer having a thickness of 10 μm, a charging roll A was obtained.

(Dispersion A)
・ 100 parts by mass of polymer material (saturated copolymer polyester resin solution Byron 30SS: manufactured by Toyobo Co., Ltd.)
Curing agent 26.3 parts by mass (amino resin solution Super Becamine G-821-60: manufactured by Dainippon Ink & Chemicals, Inc.)
-Conductive agent 10 parts by mass (carbon black MONARCH1000: manufactured by Cabot Corporation)

<Production of sheet member and process cartridge>
< Reference Example 1>
FIG. 2 shows a sheet of black high-quality paper (330 × 200 (printing direction) mm, thick mouth) and low-density polyethylene (specific gravity: 0.92, “Mirason 27” (Mitsui Chemicals)) having a thickness of 20 μm. A double-sided tape was used as the resin adhesive layer so as to be configured, and a high-quality paper and a sheet were affixed to produce a sheet member. Between the photosensitive member A and the charging roll A of the process cartridge of the color copying machine DocuCenter-IIIC3300 (manufactured by Fuji Xerox Co., Ltd.), the nip portion is the base of the sheet member so that the drawing side is in the rotational direction of the photosensitive member. The process cartridge was obtained by interposing so that the material and the resin surface layer existed. The thickness of the charge transport layer of the photoreceptor is 34 μm.

< Reference Example 2>
A sheet of black low-quality paper (330 x 200 (printing direction) mm, thick mouth) and a linear low-density polyethylene (specific gravity: 0.93, "Ultzex 2520F" (Mitsui Chemicals)) with a film thickness of 20 μm As shown in FIG. 2, a double-sided tape was used as the resin adhesive layer, and high-quality paper and a sheet were attached to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 3>
FIG. 2 shows a sheet of medium-quality polyethylene (specific gravity: 0.94, “Neozex 3510F” (manufactured by Mitsui Chemicals)) having a film thickness of 20 μm on black high-quality paper (330 × 200 (printing direction) mm, thick mouth). A double-sided tape was used as the resin adhesive layer so as to be configured, and a high-quality paper and a sheet were affixed to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 4>
FIG. 2 shows a sheet of black high-quality paper (330 × 200 (printing direction) mm, thick mouth) and high-density polyethylene (specific gravity: 0.95, “Hi-Zex 3300F” (Mitsui Chemicals)) having a film thickness of 20 μm. A double-sided tape was used as the resin adhesive layer so as to be configured, and a high-quality paper and a sheet were affixed to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 5>
A sheet of black high-quality paper (330 × 200 (printing direction) mm, thick mouth) and 20 μm-thick polypropylene (specific gravity: 0.91, “F109BA” (Grand Polymer Co., Ltd.)) is configured as shown in FIG. As described above, a double-sided tape was used as the resin adhesive layer, and high-quality paper and a sheet were attached to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 6>
A sheet of black high-quality paper (330 × 200 (printing direction) mm, thick mouth) and an ethylene-vinyl acetate copolymer (“V115” (manufactured by Ube Industries)) with a film thickness of 20 μm is configured as shown in FIG. As described above, a double-sided tape was used as the resin adhesive layer, and high-quality paper and a sheet were attached to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 7>
FIG. 2 shows a sheet of black high-quality paper (330 × 200 (printing direction) mm, thick mouth) and a metallocene-catalyzed low-density polyethylene (specific gravity: 0.92, “Evolu SP2320” (Mitsui Chemicals)) having a film thickness of 20 μm. A sheet member was prepared by using a double-sided tape as the resin adhesive layer and pasting high-quality paper and a sheet so as to have the structure shown in FIG. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 8>
A sheet of low-density polyethylene (specific gravity: 0.92, “Mirason 27” (manufactured by Mitsui Chemicals, Inc.)) having a film thickness of 20 μm on black Rash paper (330 × 200 (printing direction) mm) is configured as shown in FIG. As described above, a double-sided tape was used as the resin adhesive layer, and high-quality paper and a sheet were attached to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 9>
FIG. 4 shows a sheet of high-quality polyethylene (specific gravity: 0.95, “Hi-Zex 3300F” (manufactured by Mitsui Chemicals)) having a film thickness of 20 μm on black quality paper (330 × 200 (printing direction) mm, thick mouth). A double-sided tape was used as the resin adhesive layer so as to be configured, and a double-sided tape was affixed to the entire surface of the sheet, and high-quality paper and sort were affixed to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 10>
A black high-quality paper (330 x 200 (printing direction) mm, thick mouth) and a low-density polyethylene (specific gravity: 0.92, “Mirason 27” (Mitsui Chemicals)) with a film thickness of 20 μm remain unbonded. The cartridge was mounted in the same manner as in Reference Example 1. The cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 11>
FIG. 2 shows a sheet of low-quality polyethylene (specific gravity: 0.92, “Mirason 27” (manufactured by Mitsui Chemicals)) having a film thickness of 100 μm on black fine paper (330 × 200 (printing direction) mm, thick mouth). A double-sided tape was used as the resin adhesive layer so as to be configured, and a high-quality paper and a sheet were affixed to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 12>
FIG. 2 shows a sheet of black high-quality paper (330 × 200 (printing direction) mm, thick mouth) and low-density polyethylene (specific gravity: 0.92, “Mirason 27” (Mitsui Chemicals)) having a thickness of 20 μm. A double-sided tape was used as the resin adhesive layer so as to be configured, and a high-quality paper and a sheet were affixed to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1 except that the thickness of the charge transport layer of the photoreceptor A was changed to 37 μm.

< Reference Example 13>
FIG. 2 shows a sheet of black high-quality paper (330 × 200 (printing direction) mm, thick mouth) and low-density polyethylene (specific gravity: 0.92, “Mirason 27” (Mitsui Chemicals)) having a thickness of 20 μm. A double-sided tape was used as the resin adhesive layer so as to be configured, and a high-quality paper and a sheet were affixed to produce a sheet member. The process cartridge was prepared in the same manner as in Reference Example 1 except that the thickness of the charge transport layer of the photoreceptor A was changed to 42 μm.

< Reference Example 14>
FIG. 2 shows a sheet of black high-quality paper (330 × 200 (printing direction) mm, thick mouth) and low-density polyethylene (specific gravity: 0.92, “Mirason 27” (Mitsui Chemicals)) having a thickness of 20 μm. A double-sided tape was used as the resin adhesive layer so as to be configured, and a high-quality paper and a sheet were affixed to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1 except that the thickness of the charge transport layer of the photoreceptor A was changed to 47 μm.

< Reference Example 15>
Black high-quality paper (330 x 200 (printing direction) mm, thick mouth), carbon-containing conductive low-density polyethylene (specific gravity: 0.92, “Mirason 27” (Mitsui Chemicals)) with a thickness of 20 μm and ketjen black A double-sided tape is used as a resin adhesive layer, and a high-quality paper and a sheet are affixed so that a sheet having 4 parts by mass of EC300J and a surface resistivity: 1.0 × 10 ⁹ Ω / □ is formed as shown in FIG. Thus, a sheet member was produced. The process cartridge was produced in the same manner as in Reference Example 1.

<Example 16>
A sheet of black high-quality paper (330 x 200 (printing direction) mm, thick mouth) and a low-density polyethylene (specific gravity: 0.92, "Mirason 27" (Mitsui Chemicals)) with a film thickness of 20 µm is attached with double-sided tape. Using high-quality paper and sheet 1, a carbon-containing conductive low-density polyethylene with a film thickness of 20 μm (specific gravity: 0.92, “Mirason 27” (manufactured by Mitsui Chemicals), 4 parts by mass of Ketjen Black EC300J Sheet 2 having a composition and a surface resistivity of 1.0 × 10 ⁹ Ω / □ was attached to sheet 1 and sheet 2 using a double-sided tape to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 17>
FIG. 2 shows a sheet of conductive paper (330 × 200 (printing direction) mm, 10 ⁶ Ω) and low-density polyethylene (specific gravity: 0.92, “Mirason 27” (Mitsui Chemicals)) having a film thickness of 20 μm. Thus, a double-sided tape was used as the resin adhesive layer, and high-quality paper and a sheet were affixed to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 18>
A sheet of black high-quality paper (330 × 200 (printing direction) mm, thick mouth) and a polyethylene-polypropylene copolymer (“F569D” (manufactured by Grand Polymer)) having a thickness of 20 μm is configured as shown in FIG. In addition, a double-sided tape was used as the resin adhesive layer, and a high-quality paper and a sheet were affixed to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 19>
FIG. 2 shows a sheet of low-quality polyethylene (specific gravity: 0.92, “Mirason 27” (manufactured by Mitsui Chemicals)) having a film thickness of 10 μm on black high-quality paper (330 × 200 (printing direction) mm, thick mouth). A double-sided tape was used as the resin adhesive layer so as to be configured, and a high-quality paper and a sheet were affixed to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

<Comparative Example 1>
A process cartridge was produced in accordance with Reference Example 1 except that no sheet member was mounted.

<Comparative example 2>
A process cartridge was prepared in the same manner as in Reference Example 1 except that only black high-quality paper (330 × 200 (printing direction) mm, thick mouth) was attached as a sheet member. In addition, in the image quality evaluation described later, the image quality after printing 100 sheets of Comparative Example 2 is better than that of Comparative Example 1, and the charging history is reduced by printing. It can be seen that the generation of electric charges can be reduced simply by interposing high-quality paper.

<Comparative Example 3>
A process cartridge was prepared in the same manner as in Reference Example 1 except that conductive paper (330 × 200 (printing direction) mm, 10 ⁶ Ω) was mounted as a sheet member. In the image quality evaluation to be described later, the image quality after printing 100 sheets of Comparative Example 3 is better than that of Comparative Example 2 because the charging history is reduced by printing and compared with the high quality paper of Comparative Example 2. It can be seen that the charge generation is further reduced simply by interposing the conductive paper of Example 3.

<Comparative Example 4>
The process cartridge is a reference except that only a sheet (330 × 200 (printing direction) mm) of low-density polyethylene (specific gravity: 0.92, “Mirason 27” (manufactured by Mitsui Chemicals)) with a film thickness of 100 μm is mounted as a sheet member. Prepared in the same manner as in Example 1.

<Comparative Example 5>
Only conductive paper (330 × 200 (printing direction) mm, 10 ⁶ Ω) was mounted as a sheet member, and the process cartridge was the same as Reference Example 1 except that the thickness of the charge transport layer of the photoreceptor A was changed to 37 μm. It was prepared.

<Comparative Example 6>
Only conductive paper (330 × 200 (printing direction) mm, 10 ⁶ Ω) was mounted as a sheet member, and the process cartridge was the same as Reference Example 1 except that the thickness of the charge transport layer of the photoreceptor A was changed to 42 μm. It was prepared.

<Comparative Example 7>
Only conductive paper (330 × 200 (printing direction) mm, 10 ⁶ Ω) was mounted as a sheet member, and the process cartridge was the same as Reference Example 1 except that the thickness of the charge transport layer of the photoreceptor A was changed to 47 μm. It was prepared.

< Reference Example 20>
The structure which shows the sheet | seat of polytetrafluoroethylene ("Nitoflon film No.900UL" (made by Nitto Denko Corporation)) with a film thickness of 30 micrometers on black quality paper (330x200 (printing direction) mm, thick mouth) in FIG. Thus, a double-sided tape was used as the resin adhesive layer, and high-quality paper and a sheet were affixed to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 21>
A black high-quality paper (330 × 200 (printing direction) mm, thick mouth) with a 50 μm-thick polyvinylidene fluoride sheet (“KF sheet” (manufactured by Kureha Co.)) is a resin so as to have the configuration shown in FIG. A double-sided tape was used as the adhesive layer, and a high-quality paper and a sheet were affixed to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 22>
A black high-quality paper (330 × 200 (printing direction) mm, thick mouth) and a 50 μm-thick polyvinyl fluoride (“Full-on PFA” (Asahi Glass Co., Ltd.)) resin is used so as to have the configuration shown in FIG. A double-sided tape was used as the adhesive layer, and a high-quality paper and a sheet were affixed to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 23>
A sheet of black high-quality paper (330 × 200 (printing direction) mm, thick mouth) and a tetrafluoroethylene / ethylene copolymer (“Fluon ETFE” (manufactured by Asahi Glass Co., Ltd.)) having a film thickness of 50 μm is configured as shown in FIG. As described above, a double-sided tape was used as the resin adhesive layer, and high-quality paper and a sheet were attached to prepare a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 24>
Fig. 2 shows a sheet of black high-quality paper (330 x 200 (printing direction) mm, thick mouth) and a tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer ("Fluon PFA" (Asahi Glass Co., Ltd.)) with a film thickness of 25 µm. As shown, a double-sided tape was used as the resin adhesive layer, and high-quality paper and a sheet were affixed to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 25>
Resin bonding so that a black high-quality paper (330 × 200 (printing direction) mm, thick mouth) and a sheet of 100 μm-thick silicone rubber (“silicone film” (manufactured by ASONE)) is configured as shown in FIG. A double-sided tape was used as a layer, and a high-quality paper and a sheet were affixed to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

<Example 26>
Black high-quality paper (330 x 200 (printing direction) mm, thick mouth) is coated with an epoxy-modified silicone resin with a film thickness of 1 μm, then UV cured, and the high-quality paper has a resin surface so that the structure shown in FIG. A layer was formed to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 27>
FIG. 4 shows a black high-quality paper (330 × 200 (printing direction) mm, thick mouth) and a sheet of polytetrafluoroethylene (“Nitoflon film No. 900UL” (manufactured by Nitto Denko Corporation)) having a film thickness of 30 μm. Thus, a double-sided tape was used as the resin adhesive layer, a double-sided tape was attached to the entire surface of the sheet, and a fine paper and a sheet were attached to prepare a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 28>
Black quality paper (330 × 200 (printing direction) mm, thick mouth) and 30 μm thick polytetrafluoroethylene (“Nitoflon Film No. 900UL” (manufactured by Nitto Denko Corporation)) are left unbonded and the process cartridge Was mounted in the same manner as in Reference Example 1. The cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 29>
A sheet of black high-quality paper (330 × 200 (printing direction) mm, thick mouth) made of polytetrafluoroethylene (“Nitoflon film No. 900UL” (manufactured by Nitto Denko Corporation)) having a thickness of 100 μm is shown in FIG. Thus, a double-sided tape was used as the resin adhesive layer, and high-quality paper and a sheet were affixed to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 30>
The structure which shows the sheet | seat of polytetrafluoroethylene ("Nitoflon film No.900UL" (made by Nitto Denko Corporation)) with a film thickness of 30 micrometers on black quality paper (330x200 (printing direction) mm, thick mouth) in FIG. Thus, a double-sided tape was used as the resin adhesive layer, and high-quality paper and a sheet were affixed to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1 except that the thickness of the charge transport layer of the photoreceptor A was changed to 37 μm.

< Reference Example 31>
The structure which shows the sheet | seat of polytetrafluoroethylene ("Nitoflon film No.900UL" (made by Nitto Denko Corporation)) with a film thickness of 30 micrometers on black quality paper (330x200 (printing direction) mm, thick mouth) in FIG. Thus, a double-sided tape was used as the resin adhesive layer, and high-quality paper and a sheet were affixed to produce a sheet member. The process cartridge was prepared in the same manner as in Reference Example 1 except that the thickness of the charge transport layer of the photoreceptor A was changed to 42 μm.

< Reference Example 32>
The structure which shows the sheet | seat of polytetrafluoroethylene ("Nitoflon film No.900UL" (made by Nitto Denko Corporation)) with a film thickness of 30 micrometers on black quality paper (330x200 (printing direction) mm, thick mouth) in FIG. Thus, a double-sided tape was used as the resin adhesive layer, and high-quality paper and a sheet were affixed to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1 except that the thickness of the charge transport layer of the photoreceptor A was changed to 47 μm.

<Comparative Example 8>
The process cartridge was produced in the same manner as in Reference Example 1 except that only a sheet (330 × 200 (printing direction) mm) of a silicone resin (“silicon film” (manufactured by ASONE)) having a film thickness of 100 μm was mounted as the sheet member.

<Comparative Example 9>
The process cartridge is a reference example, except that only a sheet (330 × 200 (printing direction) mm) of polytetrafluoroethylene (“Nitoflon film No. 900UL” (manufactured by Nitto Denko Corporation)) having a film thickness of 100 μm is mounted as a sheet member. 1 was produced.

< Reference Example 33>
A black high-quality paper (330 × 200 (printing direction) mm, thick mouth) and a 20 μm-thick ester polyurethane (“Cranziel U-1490” (Kurabo Co., Ltd.)) sheet is configured as shown in FIG. Then, a double-sided tape was used as the resin adhesive layer, and a high-quality paper and a sheet were affixed to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 34>
A black high-quality paper (330 × 200 (printing direction) mm, thick mouth) and a 20 μm-thick ether polyurethane (“Cranziel U-1390” (manufactured by Kurabo Industries)) sheet is configured as shown in FIG. Then, a double-sided tape was used as the resin adhesive layer, and a high-quality paper and a sheet were affixed to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 35>
A sheet of polyethylene fine terephthalate (PET) (“Tetron Film GE” (manufactured by Teijin DuPont Films)) with a film thickness of 20 μm on black fine paper (330 × 200 (printing direction) mm, thick mouth) is configured as shown in FIG. As described above, a double-sided tape was used as the resin adhesive layer, and high-quality paper and a sheet were attached to prepare a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 36>
FIG. 2 shows a sheet of black high-quality paper (330 × 200 (printing direction) mm, thick mouth) and 20 μm-thick polybutylene terephthalate (PBT) (“DURANEX 200FP” (manufactured by Wintech Polymer)). Thus, a double-sided tape was used as the resin adhesive layer, and high-quality paper and a sheet were affixed to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

<Comparative Example 10>
The process cartridge is the same as in Reference Example 1 except that only a sheet (330 × 200 (printing direction) mm) of an ether-based polyurethane (“Cranziel U-1390” (manufactured by Kurabo Industries)) having a film thickness of 100 μm is mounted as a sheet member. Produced.

<Comparative Example 11>
The process cartridge is Reference Example 1 except that only a sheet (330 × 200 (printing direction) mm) of polyethylene terephthalate (PET) (“Tetron Film GE” (manufactured by Teijin DuPont Films)) having a film thickness of 100 μm is mounted as a sheet member. It produced similarly.

<Example 37>
A polyamide resin (“Amilan CM8000” (manufactured by Toray Industries, Inc.) dissolved in methanol having a thickness of 20 μm is applied to black high-quality paper (330 × 200 (printing direction) mm, thick mouth), and the structure shown in FIG. 8 is obtained. Thus, a resin surface layer was formed on high-quality paper to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

<Example 38>
A polyamide resin (“Amilan CM8000” (manufactured by Toray Industries, Inc.)) dissolved in methanol with a film thickness of 20 μm is applied to black Rash paper (330 × 200 (printing direction) mm) so that the configuration shown in FIG. A resin surface layer was formed on fine paper to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 39>
As shown in FIG. 2, a sheet of polyimide resin (“Kapton 100H” (manufactured by Toray DuPont)) with a film thickness of 25 μm is applied to black high-quality paper (330 × 200 (printing direction) mm, thick mouth). A double-sided tape was used as the resin adhesive layer, and a high-quality paper and a sheet were attached to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 40>
Resin adhesive layer so that a sheet of black Rash paper (330 × 200 (printing direction) mm) and a polyimide resin (“Kapton 100H” (manufactured by Toray DuPont)) with a film thickness of 25 μm is configured as shown in FIG. Using a double-sided tape, a high-quality paper and a sheet were pasted to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 41>
As shown in FIG. 2, a sheet of polyamideimide resin (“Vilomax HR12N2” (manufactured by Toyobo Co., Ltd.)) with a film thickness of 20 μm is applied to black high-quality paper (330 × 200 (printing direction) mm, thick mouth). A double-sided tape was used as the resin adhesive layer, and a high-quality paper and a sheet were attached to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

<Comparative Example 12>
A process cartridge was prepared in the same manner as in Reference Example 1 except that only a sheet (330 × 200 (printing direction) mm) of a polyamide resin (“Amilan CM8000” (manufactured by Toray Industries, Inc.)) having a film thickness of 100 μm was mounted as a sheet member.

<Comparative Example 13>
The process cartridge is manufactured in the same manner as Reference Example 1 except that only a sheet (330 × 200 (printing direction) mm) of a polyimide resin (“Kapton 500H” (manufactured by Toray DuPont)) having a film thickness of 125 μm is mounted as a sheet member. did.

<Example 42>
A black high-quality paper (330 × 200 (printing direction) mm, thick mouth) is coated with a phenol resin (“Sumilite Resin PR50209” (manufactured by Sumitomo Bakelite Co., Ltd.)) having a film thickness of 10 μm so that the configuration shown in FIG. In addition, a resin surface layer was formed on high quality paper to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

<Example 43>
A black resin paper (330 × 200 (printing direction) mm) is coated with a phenol resin (“Sumilite Resin PR50209” (manufactured by Sumitomo Bakelite Co., Ltd.)) having a film thickness of 10 μm. A resin surface layer was formed on paper to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 44>
A black high-quality paper (330 × 200 (printing direction) mm, thick mouth) is bonded to a resin sheet so that a 20 μm-thick polyacetal resin (“Derlin 900P” (manufactured by DuPont)) is formed as shown in FIG. A double-sided tape was used as a layer, and a high-quality paper and a sheet were affixed to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

< Reference Example 45>
A sheet of black arusha paper (330 × 200 (printing direction) mm) and a polyacetal resin (“Derlin 900P” (manufactured by DuPont)) with a thickness of 20 μm is used as a resin adhesive layer so as to have the structure shown in FIG. Using a tape, a high-quality paper and a sheet were pasted to produce a sheet member. The process cartridge was produced in the same manner as in Reference Example 1.

<Comparative example 14>
The process cartridge is the same as Reference Example 1 except that only a sheet (330 × 200 (printing direction) mm) of a phenol resin (“Sumilite Resin PR50209” (Sumitomo Bakelite Co., Ltd.)) having a film thickness of 100 μm is mounted as a sheet member. Produced.

<Comparative Example 15>
A process cartridge was prepared in the same manner as Reference Example 1 except that only a sheet (330 × 200 (printing direction) mm) of a polyacetal resin (“Derlin 900P” (manufactured by DuPont)) having a film thickness of 100 μm was mounted as a sheet member.

<Evaluation>
-Vibration test-
The process cartridge was packed, and vibration with an amplitude of 25 mm, a frequency of 10 Hz, and an acceleration of 7 mm / s ² was applied for 4 hours.

-Strong vibration test-
The process cartridge was packed, and vibration with an amplitude of 25 mm, a frequency of 300 Hz, and an acceleration of 7 mm / s ² was applied for 4 hours.

-Image quality evaluation-
After the vibration test, the sheet member is pulled out and removed, the process cartridge is mounted on the DocuCentre-IIIC3300 (Fuji Xerox Co., Ltd.), a 50% halftone image of magenta is printed in A3, and the first image quality (initial image quality) is obtained. Visual evaluation was performed. Further, the image quality evaluation after printing 10 sheets and 100 sheets was further printed, and the image quality of the 10th sheet and the 100th sheet was visually evaluated. The printing environment was 22 ° C. and 55% RH. The indexes for image quality evaluation are as follows. Note that up to C is acceptable.
A: No image quality defect occurred.
B: An extremely slight color streak or image quality defect that can be visually confirmed occurs.
C: Minor color streaks or image quality defects occur.
D: Color streaks or image quality defects occur.
E: Strong color streaks or image quality defects occur.

  As an application example of the present invention, there is application to an image forming apparatus such as a copying machine or a printer using an electrophotographic system.

  11 Electrophotographic photoreceptor, 12 Conductive substrate, 13 Photosensitive layer, 14 Undercoat layer, 15 Charge generation layer, 16 Charge transport layer, 17 Surface protective layer, 18 Intermediate layer, 20, 30, 40, 50 Sheet member, 22 Base material, 24 resin surface layer, 26, 36 resin adhesive layer, 28 resin layer, 100, 110 case, 102, 112 opening, 200, 210, 220 image forming device, 206 exposure device, 207 photoconductor, 207 electrophotography Photoconductor, 208 charging device, 209 power supply, 211 developing device, 212a primary transfer member, 212b secondary transfer member, 212 transfer device, 213 cleaning device, 214 static eliminator, 215 fixing device, 216 mounting rail, 217, 218 opening Part, 400 housing, 401a, 401b, 401c, 401d electrophotographic photosensitive member, 4 02a, 402b, 402c, 402d Charging roll, 403 Laser light source, 404a, 404b, 404c, 404d Developing device, 405a, 405b, 405c, 405d Toner cartridge, 406 Drive roll, 407 Tension roll, 408 Support roll, 409 Intermediate transfer Belt, 410a, 410b, 410c, 410d Primary transfer roll, 411 tray, 412 transfer roll, 413 secondary transfer roll, 414 fixing roll, 415a, 415b, 415c, 415d cleaning blade, 416 cleaning blade, 500 medium to be transferred.

Claims (4)

A charging means for contacting the surface of the image carrier with the image carrier and charging the surface with a charging member;
It saw including a a substrate comprising a nonwoven fabric and a direction pulling out during use and the opposite side resin surface layer provided on one end of a first resin layer and second resin layer between the resin surface layer and the base material The sheet member whose resistance value of the resin surface layer in contact with the image carrier and the resistance value of the first resin layer in contact with the base material is lower than the resistance value of the second resin layer is used for the unused image. A process cartridge, wherein the resin surface layer is interposed between a carrier and a charging member so as to contact the image carrier, and the sheet member is pulled out during use. The resin surface layer is a polyolefin, fluororesin, claim wherein the silicone resin, polyurethane, polyester, acrylic copolymers, polyamides, polyimides, phenolic resins, in that it consists of a resin selected from the group consisting of polyacetal 1 the process cartridge according to. A charging means for contacting the surface of the image carrier with the image carrier and charging the surface with a charging member;
A sheet member including a base material made of a nonwoven fabric and a resin surface layer provided at one end opposite to a direction to be pulled off when used, the resin surface layer is between the unused image carrier and the charging member. Intervening in contact with the carrier,
The process cartridge according to claim 1, wherein an end portion of the interposed sheet member has a folded portion folded to the image carrier side. An image forming apparatus comprising: a process cartridge according to any one of claims 1 to 3.