JP2008040241A - Charging roll, process cartridge and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a charging roll capable of retaining satisfactory charging characteristics in which peeling resulting from contact failure and adherence failure caused between an elastic layer and a functional layer formed on the elastic layer is prevented and hence nonuniform charging is prevented for a long time. <P>SOLUTION: The charging roll includes: a conductive support 1; the elastic layer 2 formed on the conductive support 1; and the functional layer 4 formed on the elastic layer 2. The elastic layer 2 and the functional layer 4 are bonded together via an adhesive layer 3 formed on at least one end of the elastic layer 2 in the axial direction of the charging roll. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

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

  In an image forming apparatus using an electrophotographic system, a laser beam that modulates an image signal by forming a uniform charge on an electrophotographic photosensitive member (hereinafter, abbreviated as “photosensitive member” in some cases) as an image carrier. After the electrostatic latent image is formed by the above, the electrostatic latent image is developed with a charged toner to obtain a visualized toner image. Then, a desired transfer image can be obtained by electrostatically transferring the toner image to the recording medium via the intermediate transfer member.

  As described above, in an image forming apparatus using an electrophotographic method, a charging process for forming a uniform charge on a photoconductor is performed. One type of charging member that performs this charging process is a contact-type charging roll, which is widely used. The contact-type charging roll generally has a small current to be applied, and has an advantage that the amount of ozone generation is very small compared to the corotron or scorotron which is a non-contact type charging member.

  As the charging roll, at least an elastic layer made of rubber or elastomer is formed on a conductive support made of metal or alloy such as stainless steel; iron or the like plated with chromium, nickel or the like. Is widely used. On the elastic layer, functional layers such as a resistance layer and a surface layer are formed as necessary.

  Such a charging roll is required to have adhesion and adhesion between each layer. If there is an adhesion failure or adhesion failure between the layers, uneven resistance or deformation of the charging roll will occur. Therefore, in order to improve the adhesion between the layers, a method for improving the adhesion and adhesion by forming an adhesion layer between the layers has been proposed (for example, see Patent Document 1). However, when an adhesive layer is formed between the layers, if the conductivity is not imparted to the adhesive layer, uneven resistance and increased resistance are caused.

If gaps are generated between layers due to poor adhesion or poor adhesion between layers, or if there is uneven resistance in the formed adhesive layer, uneven charging occurs when the photoreceptor is charged. Therefore, in order to improve resistance unevenness of the adhesive layer, a conductivity imparting agent such as carbon black is added to impart conductivity to the adhesive layer (see, for example, Patent Documents 2 and 3).
JP-A-8-123139 JP 58-202468 A Japanese Patent Laid-Open No. 2-310666

  However, in the adhesive layers described in Patent Documents 2 and 3, the adhesive strength of the adhesive layer is reduced by containing the conductivity imparting agent. Particularly in recent years, in image forming apparatuses, there is an increasing demand for higher image quality and longer life, and the charging roll has a gap due to poor adhesion or poor adhesion between layers as compared to conventional cases, and when an adhesive layer is formed. Unevenness of resistance of the adhesive layer and unevenness of charging due to the presence of a high resistance portion are likely to occur over time. In particular, the contact-type charging roll is required to have sufficient adhesiveness and adhesion between the elastic layer and the upper layer because the elastic layer is deformed during use.

  The present invention has been made in view of the above-described problems of the prior art, and the occurrence of peeling due to poor adhesion and poor adhesion between the elastic layer and the functional layer formed on the elastic layer is sufficiently suppressed. Another object of the present invention is to provide a charging roll capable of maintaining good charging characteristics in which charging unevenness is suppressed over a long period of time, and a process cartridge and an image forming apparatus using the same.

  In order to achieve the above object, the present invention comprises a conductive support, an elastic layer formed on the conductive support, and a functional layer formed on the elastic layer. Provided is a charging roll in which the layer and the functional layer are bonded via an adhesive layer formed on at least one end of the elastic layer in the charging roll axial direction.

  When the charging roll is used for a long period of time, peeling between the elastic layer and the functional layer formed on the elastic layer is likely to occur from the axial end of the charging roll. This is presumably because deformation of the elastic layer is likely to occur at the end portion, where air entrainment or the like occurs and a separation starting point is formed. In the charging roll of the present invention, by forming the adhesive layer at the end where the deformation amount of the elastic layer is large, it is possible to suppress the occurrence of a peeling start point between the elastic layer and the functional layer. Generation | occurrence | production of peeling between a functional layer can fully be suppressed. Further, in the charging roll of the present invention, since the adhesive layer is formed only at the end portion on the elastic layer, it is possible to suppress the occurrence of uneven charging on the object to be charged due to the uneven resistance of the adhesive layer. . Therefore, it is not necessary to add a large amount of conductive agent to the adhesive layer in order to improve the resistance unevenness of the adhesive layer, and a sufficient adhesive force can be given to the adhesive layer. Therefore, according to the charging roll of the present invention, it is possible to sufficiently suppress the occurrence of peeling between the elastic layer and the functional layer, and to maintain good charging characteristics in which charging unevenness is suppressed over a long period of time. it can.

  Here, the adhesive layer is preferably formed at both ends of the elastic layer in the charging roll axial direction. Even if the adhesive layer is formed only at one end on the elastic layer, it has the effect of suppressing delamination between the elastic layer and the functional layer. Generation of the starting point can be sufficiently suppressed, peeling between the elastic layer and the functional layer can be more sufficiently suppressed, and stable charging characteristics can be maintained over a longer period.

  The adhesive layer is preferably formed in an end region of the charging roll that is in contact with the non-image region of the charged body. As a result, even when there is uneven resistance in the adhesive layer, uniform charging can be performed on the image area of the member to be charged, so that the required charging characteristics can be sufficiently satisfied.

Furthermore, the volume resistivity of the adhesive layer is preferably 1 × 10 ¹⁰ Ω · cm or more. By setting the volume resistivity of the adhesive layer in the above range, the content of the conductive agent in the adhesive layer can be sufficiently lowered, and the adhesive force of the adhesive layer can be made sufficient. Thereby, peeling between an elastic layer and a functional layer can be suppressed more fully over a long period of time.

  The elastic layer is preferably a layer containing silicone rubber. Silicone rubber is excellent in tackiness, so that the adhesion between the elastic layer and the functional layer can be improved in a region where the adhesive layer is not formed, and peeling between the elastic layer and the functional layer can be performed for a long time. Can be more fully suppressed.

Furthermore, the volume resistivity of the elastic layer is preferably 1 × 10 ⁸ Ω · cm or less. As a result, a sufficient current flows in the portion where the adhesive layer is formed as well as in the portion where the adhesive layer is not formed, and the resistance unevenness of the adhesive layer forming portion can be more sufficiently suppressed.

  The present invention also provides a charging unit having a charging roll for charging the electrophotographic photosensitive member by a contact charging method, and developing the electrophotographic photosensitive member and the electrostatic latent image formed on the electrophotographic photosensitive member with toner. And at least one selected from the group consisting of a developing means for forming a toner image and a cleaning means for removing the toner remaining on the surface of the electrophotographic photosensitive member. A conductive support, an elastic layer formed on the conductive support, and a functional layer formed on the elastic layer, and the elastic layer and the functional layer are provided on the elastic layer. Provided is a process cartridge which is bonded through an adhesive layer formed at least at one end in the charging roll axial direction.

  The present invention further includes an electrophotographic photosensitive member, a charging unit having a charging roll for charging the electrophotographic photosensitive member by a contact charging method, and an electrostatic latent image formed on the charged electrophotographic photosensitive member. An exposure unit; a developing unit for developing the electrostatic latent image with toner to form a toner image; and a transfer unit for transferring the toner image from the electrophotographic photosensitive member to a transfer target. The charging roll has a conductive support, an elastic layer formed on the conductive support, and a functional layer formed on the elastic layer, and the elastic layer and the functional layer Is bonded via an adhesive layer formed on at least one end in the charging roll axial direction on the elastic layer.

  According to the process cartridge and the image forming apparatus of the present invention, since the above-described charging roll of the present invention is used, good charging characteristics are maintained over a long period of time, and an image with good image quality can be stably formed. it can.

  According to the present invention, the occurrence of peeling due to poor adhesion and poor adhesion between the elastic layer and the functional layer is sufficiently suppressed, and it is possible to maintain good charging characteristics in which charging unevenness is suppressed over a long period of time. A charging roll, and a process cartridge and an image forming apparatus using the same can be provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings. In the drawings, the same or corresponding parts are denoted by the same reference numerals, and redundant description is omitted.

(Charging roll)
The charging roll of the present invention has a conductive support, an elastic layer formed on the conductive support, and a functional layer formed on the elastic layer, the elastic layer and the functional layer Are bonded via an adhesive layer formed on at least one end portion of the elastic layer in the charging roll axial direction. Here, FIG. 1 is a perspective view showing a preferred embodiment of the charging roll of the present invention, FIG. 2 is a schematic cross-sectional view taken along the line II of FIG. 1, and FIG. FIG. 4 is a schematic cross-sectional view taken along the line -II, and FIG. 4 is a schematic cross-sectional view taken along the line III-III in FIG.

  1 to 4 includes a conductive support 1, an elastic layer 2 formed on the conductive support 1, and a resistance layer 4 as a functional layer formed on the elastic layer 2. And a surface layer 5 formed on the resistance layer 4, and the elastic layer 2 and the resistance layer 4 are formed on both ends of the charging roll 10 in the axial direction on the elastic layer 2. It has the structure adhered via. 2 to 4, the adhesive layer 3 is formed only on the elastic layer 2 at both ends in the axial direction of the charging roll 10, and the central portion of the elastic layer 2 is in direct contact with the resistance layer 4. 3 is a cross-sectional view of a region (center portion) where the adhesive layer 3 is not formed, and FIG. 4 is a cross-sectional view of a region (end portion) where the adhesive layer 3 is formed. Hereinafter, each layer will be described.

  The conductive support 1 functions as an electrode and a support member of the charging roll 10, for example, a metal or an alloy such as aluminum, copper alloy, or stainless steel; iron that has been plated with chromium, nickel, or the like; A conductive material such as a conductive resin; Among these, metals and alloys are particularly preferable. The diameter of the conductive support 1 is not particularly limited, but is preferably 5 to 9 mm, and more preferably 6 to 8 mm.

  The elastic layer 2 is formed, for example, by dispersing a conductive agent in a rubber material as necessary. Rubber materials include isoprene rubber, chloroprene rubber, epichlorohydrin rubber, butyl rubber, polyurethane rubber, fluorine rubber, styrene-butadiene rubber, butadiene rubber, nitrile rubber, ethylene propylene rubber, epichlorohydrin-ethylene oxide copolymer rubber, epichlorohydrin-ethylene oxide-allyl glycidyl. Examples thereof include ether copolymer rubber, ethylene-propylene-diene terpolymer rubber (EPDM), acrylonitrile-butadiene copolymer rubber (NBR), natural rubber, and blend rubbers thereof. Among these, the silicone rubber having tackiness is preferable because the adhesiveness with the functional layer is good even in the portion where the adhesive layer 3 is not formed when the elastic layer 2 having a low hardness desired in recent years is used. These rubber materials may be foamed or non-foamed.

  As the conductive agent, an electronic conductive agent or an ionic conductive agent is used. Examples of electronic conductive agents include carbon blacks such as ketjen black and acetylene black; pyrolytic carbon, graphite; various conductive metals or alloys such as aluminum, copper, nickel, and stainless steel; tin oxide, indium oxide, titanium oxide Examples thereof include various conductive metal oxides such as a tin oxide-antimony oxide solid solution and a 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 electrically conductive agents can be used individually by 1 type or in combination of 2 or more types.

  When the conductive agent is contained in the elastic layer 2, the content thereof is not particularly limited, but in the case of the electronic conductive agent, it is preferably in the range of 1 to 30 parts by mass with respect to 100 parts by mass of the rubber material. A range of 5 to 25 parts by mass is more preferable. On the other hand, in the case of the ionic conductive agent, it is preferably in the range of 0.1 to 5.0 parts by mass, and in the range of 0.5 to 3.0 parts by mass with respect to 100 parts by mass of the rubber material. More preferred.

  In addition to the rubber material and the conductive agent, materials necessary for vulcanization, various fillers, and the like may be added to the elastic layer 2.

The volume resistivity of the elastic layer 2 is preferably 1 × 10 ⁸ Ω · cm or less, and more preferably 1 × 10 ⁶ Ω · cm or less.

  The elastic layer 2 can be formed, for example, on the conductive support 1 coated with an adhesive by a method such as an injection molding method, a press molding method, or an extrusion molding using the composition containing each component described above. it can. As the adhesive, for example, a polyolefin-based resin, a chlorinated rubber-based resin, an epoxy-based resin, a phenol-based resin, a silicone-based resin, or a rubber, or a silane coupling agent can be used.

  The thickness of the elastic layer is preferably 1.0 to 4.0 mm, and more preferably 2.0 to 3.0 mm.

  The adhesive layer 3 is not particularly limited as long as it is a layer capable of adhering the elastic layer 2 and the upper functional layer. Examples of the adhesive component constituting the adhesive layer 3 include polyolefin-based, chlorinated rubber-based, epoxy-based, phenol-based, silicone-based resins or rubbers. When silicone rubber is used for the elastic layer 2, it is preferable to use a silicone-based resin or rubber, particularly using a silane coupling agent, in consideration of adhesion to the silicone rubber, uneven resistance, and uneven film thickness. preferable.

In order to impart conductivity to the adhesive layer 3, a conductivity imparting agent (conductive agent) can also be added. As the conductivity-imparting agent, the same conductive agent as that used for the elastic layer 2 can be used. If the volume resistivity of the adhesive layer 3 is adjusted to be less than 1 × 10 ¹⁰ Ω · cm, the amount of the conductivity-imparting agent is increased and the adhesiveness is lowered. Therefore, the volume resistivity of the adhesive layer is 1 × preferably adjusted to more than ^{10 10 Ω} · cm, and more preferably adjusted to more than 1 × ^{10 13 Ω} · cm. Further, from the viewpoint of improving the adhesiveness of the adhesive layer 3, the content of the conductivity imparting agent is preferably 10% by mass or less, preferably 5% by mass or less, based on the total amount of the adhesive layer 3. Is more preferable.

  For example, the adhesive layer 3 is a method such as brush coating, spray coating, roll coating, dip coating, or flow coating with a coating solution for forming an adhesive layer containing an adhesive component and a conductivity imparting agent used as necessary. Can be formed by applying to both ends of the elastic layer 2.

  The thickness of the adhesive layer 3 is not particularly limited as long as it does not affect the resistance unevenness and film thickness unevenness of the layer formed on the outer side, but is preferably 100 μm or less, and preferably 50 μm or less. More preferred.

  The positions where the adhesive layer 3 is formed are both ends in the axial direction of the charging roll 10 on the elastic layer 2, but the adhesive layer 3 is a non-image region of the object to be charged from the viewpoint of sufficiently suppressing the occurrence of charging unevenness. It is particularly preferable that it is formed in the end region of the charging roll 10 in contact with the surface. Further, the width of the adhesive layer 3 in the axial direction of the charging roll 10 may be in a range included in the end region of the charging roll 10 corresponding to the non-image region of the member to be charged. Although it depends on the region, it is usually preferable to form it with a width of 50 mm or less inward from the end of the charging roll 10, and more preferably with a width of 5 to 30 mm. Further, since it is preferable that the end region of the charging roll 10 on which the adhesive layer 3 is formed does not come into contact with the image area of the member to be charged, the charging roll 10 has an area where the adhesive layer 3 is not formed (adhesive layer not yet formed). It is preferable that the image forming area has a width equal to or larger than the size of the image area. That is, for example, when the object to be charged has an A3 size image region, the width of the region where the adhesive layer 3 is not formed on the charging roll 10 is preferably 300 mm or more in the axial direction of the charging roll 10. By forming the adhesive layer 3 so as to satisfy these conditions, the charging roll 10 can perform more uniform charging with respect to the image area of the member to be charged, and sufficiently suppress the occurrence of charging unevenness. It becomes possible.

  The resistance layer 4 is a functional layer that is bonded to the elastic layer 2 via the adhesive layer 3 at both ends in the axial direction of the charging roll 10. The surface layer 5 is a layer further formed on the resistance layer 4.

  The resistance layer 4 and the surface layer 5 are formed, for example, by dispersing a conductive agent in a polymer material. The polymer material is not particularly limited. For example, polyamide resin, polyurethane resin, polyvinylidene fluoride resin, tetrafluoroethylene copolymer, polyester resin, polyimide resin, silicone resin, acrylic resin, polyvinyl butyral resin, ethylene tetra Resin materials such as fluoroethylene copolymer, melamine resin, fluorine resin, epoxy resin, polycarbonate resin, polyvinyl alcohol resin, cellulose resin, polyvinylidene chloride resin, polyvinyl chloride resin, polyethylene resin, ethylene vinyl acetate copolymer, The rubber material etc. which were used for the elastic layer 2 are mentioned. These polymer materials may be used alone or in a combination of two or more.

  As the conductive agent, the same conductive agent as that used for the elastic layer 2 can be used. The content of the conductive agent in the resistance layer 4 is not particularly limited, but when the electronic conductive agent is used as the conductive agent, it is preferably in the range of 1 to 30 parts by mass with respect to 100 parts by mass of the polymer material. A range of 25 parts by mass is more preferable. On the other hand, when using the said ionic conductive agent, it is preferable that it is the range of 0.1-5.0 mass parts with respect to 100 mass parts of polymeric materials, and is the range of 0.5-3.0 mass parts. It is more preferable. Further, the content of the conductive agent in the surface layer 5 is not particularly limited, but is preferably in the range of 1 to 50 parts by mass, and in the range of 5 to 20 parts by mass with respect to 100 parts by mass of the polymer material. More preferred.

  In addition, metal oxide such as silicon oxide, aluminum oxide and barium titanate and composite metal oxide, and polymer fine powder such as tetrafluoroethylene and vinylidene fluoride are added to the surface layer 5 alone or in combination. You can also

  The resistance layer 4 can be formed, for example, by applying a resistance layer forming coating solution obtained by dissolving or dispersing the above-described components in an organic solvent or water onto the elastic layer 2 and the adhesive layer 3. The surface layer 5 can be formed, for example, by applying a coating solution for forming a surface layer formed by dissolving or dispersing the above-described components in an organic solvent or water onto the resistance layer 4.

  In particular, the functional layer (resistive layer 4) formed on the elastic layer 2 and the adhesive layer 3 is preferably formed by coating using the coating solution. By forming the resistance layer 4 by coating, voids are not easily formed between the elastic layer 2 and the resistance layer 4, and adhesion is increased, so that an unformed portion of the adhesive layer 3 (the elastic layer 2 and the resistance layer 4 are connected to each other). Adequate adhesion can be ensured even in direct contact portions).

  In the case of forming a layer by coating, the coating method of the coating liquid is not particularly limited, and methods such as dip (dip) coating, spray coating, roll coating, push-up coating, and flow coating, which are widely used as coating techniques, are used. be able to.

  Although the thickness of the resistance layer 4 is not specifically limited, It is preferable that it is 200-1000 micrometers, and it is more preferable that it is 300-600 micrometers.

  Moreover, although the thickness of the surface layer 5 is not specifically limited, It is preferable that it is 1-50 micrometers, and it is more preferable that it is 3-20 micrometers.

  As mentioned above, although one suitable embodiment of the charging roll of this invention was described, this invention is not limited to the said embodiment. For example, in the charging roll 10 shown in FIGS. 1 to 4, the case where the adhesive layer 4 is formed on both ends in the axial direction of the charging roll 10 on the elastic layer 2 has been described. The layer 4 may be formed on one end in the axial direction of the charging roll 10 on the elastic layer 2.

  Further, the adhesive layer 4 does not necessarily have to be continuously formed in the circumferential direction of the charging roll 10 and is intermittent while having a portion where the adhesive layer 4 is not formed as long as the effect of the present invention is not impaired. It may be formed automatically. Further, the width of the adhesive layer 4 (the width in the axial direction of the charging roll 10) is not necessarily constant as long as the effect of the present invention is not impaired.

  1 to 4, the case where the resistance layer 4 and the surface layer 5 are provided on the elastic layer 2 and the adhesive layer 3 has been described. However, the charging roll of the present invention includes the elastic layer 2 and the adhesive layer 3. It suffices to have at least one functional layer on the layer 3. For example, the charging roll 10 may not have the resistance layer 4 or the surface layer 5. When the charging roll 10 does not have the resistance layer 4, the surface layer 5 is a functional layer formed on the elastic layer 2 and the adhesive layer 3. In this case, the thickness of the surface layer 5 is preferably 1 to 100 μm, and more preferably 3 to 20 μm. The charging roll of the present invention may further have a layer other than the resistance layer 4 and the surface layer 5 on the elastic layer 2 and the adhesive layer 3. Furthermore, in the charging roll of the present invention, the layer formed on the functional layer may be formed of, for example, a resin tube.

  Next, a method for measuring the volume resistivity of each layer constituting the charging roll 10 will be described. The measurement of the volume resistivity in the present invention is performed using a sheet sample of each layer as a measurement object so that the volume resistivity of each layer can be measured separately. As shown in FIG. 5, electrodes (advantest R12702A / B resilience chamber) 14 and 15 are attached to both sides of the sheet sample 11, and the sheet sample 11 has a ring coaxially with the electrode 14 on one side. A ground electrode 16 is further attached, and a high resistance measuring device (R8340A digital high resistance / microammeter manufactured by Advantest) 13 having an ammeter 21 and a power source 22 is connected to the electrodes 14, 15, 16.

The volume resistivity (Ω · cm) is calculated by applying the voltage adjusted so that the electric field (applied voltage / sheet sample thickness) is 1000 V / cm to the electrodes 14 and 15 and charging it for 10 seconds using the following formula ( 1). The measurement is performed in an environment of 23 ° C. and 55% RH.
Volume resistivity (Ω · cm) = {19.63 × applied voltage (V) × sheet sample thickness (cm)} / current value (A) (1)

The charging roll resistance is measured by the method described in JP-A-6-118105. In the present invention, an electrode made of a cylindrical SUS bearing having a width of 5 mm is brought into contact with the surface of the charging roll with a weight of 25 g, and the resistance between the electrode and the conductive support is reduced while rotating the charging roll at 5.5 rpm. measure. A high resistance measuring instrument (manufactured by Advantest, R8340A digital high resistance / microammeter) is used for the power source and ammeter. The applied voltage is 100 V, and the charging roll resistance is calculated using the following formula (2).
Charging roll resistance (log Ω) = log ₁₀ {applied voltage (V) / current (A)} (2)

(Image forming apparatus and process cartridge)
Next, an image forming apparatus and a process cartridge equipped with the charging roll of the present invention will be described.

  The image forming apparatus of the present invention includes an electrophotographic photosensitive member as a member to be charged, a charging unit having the charging roll of the present invention for charging the electrophotographic photosensitive member by a contact charging method, and the charged electrophotographic image. An exposure means for forming an electrostatic latent image on the photoreceptor, a developing means for developing the electrostatic latent image with toner to form a toner image, and the toner image transferred from the electrophotographic photoreceptor And a transfer means for transferring to the body.

  First, an electrophotographic photoreceptor used in the image forming apparatus of the present invention will be described. 6 to 10 are schematic cross-sectional views each showing a preferred example of the electrophotographic photosensitive member, which is obtained by cutting the electrophotographic photosensitive member along a plane perpendicular to the stacking direction of the substrate and the photosensitive layer. The electrophotographic photoreceptors shown in FIGS. 6 to 9 are all function-separated photoreceptors, and the photosensitive layer 36 provided in each photoreceptor contains a charge generation layer 31 containing a charge generation material and a charge transport material. The charge transport layer 32 is provided separately. On the other hand, the electrophotographic photosensitive member shown in FIG. 10 is a single layer type photosensitive member, and is provided with a single layer type photosensitive layer 38 containing both a charge generating material and a charge transporting material.

  More specifically, in the electrophotographic photoreceptor 100 shown in FIG. 6, a photosensitive layer 36 in which a charge generation layer 31 and a charge transport layer 32 are laminated in this order on a conductive substrate 33 is formed. In the electrophotographic photoreceptor 110 shown in FIG. 7, an undercoat layer 34 and a photosensitive layer 36 in which a charge generation layer 31 and a charge transport layer 32 are laminated in this order are sequentially formed on a conductive substrate 33. ing. In the electrophotographic photoreceptor 120 shown in FIG. 8, the undercoat layer 34, the charge generation layer 31 and the charge transport layer 32 are laminated in this order on the conductive substrate 33, and the protective layer 35. Are sequentially formed. In the electrophotographic photoreceptor 130 shown in FIG. 9, a photosensitive layer 36 in which an undercoat layer 34, an intermediate layer 7, a charge generation layer 31 and a charge transport layer 32 are laminated in this order on a conductive substrate 33. And the protective layer 35 are sequentially formed. In the electrophotographic photoreceptor 140 shown in FIG. 10, a single layer type photosensitive layer 38 is formed on a conductive substrate 33. Hereinafter, each layer constituting the electrophotographic photosensitive member will be described mainly based on the electrophotographic photosensitive member 130 shown in FIG.

  The conductive substrate 33 is not particularly limited. For example, a metal drum such as aluminum, copper, iron, zinc, nickel, etc .; aluminum, copper, gold, silver on a polymer sheet, paper, plastic, or glass , Platinum, palladium, titanium, nickel-chromium, stainless steel, copper-indium, etc., a drum-like, sheet-like or plate-like substrate subjected to conductive treatment by vapor deposition; on a polymer sheet, paper, plastic or glass A drum-like, sheet-like or plate-like substrate subjected to a conductive treatment by vapor-depositing a conductive metal compound such as indium oxide or tin oxide or laminating a metal foil; carbon black, indium oxide, tin oxide-antimony oxide Powder, metal powder, copper iodide, etc. are dispersed in a binder resin, and a polymer sheet, paper, plastic Click, or glass over the conductive-treated drum-like by applying to a sheet, such as a plate-like substrate and the like.

  Here, when a metal drum is used as the conductive substrate 33, the outer peripheral surface (the surface on the side where the photosensitive layer 36 is formed) may remain a raw tube, but in advance, mirror cutting, etching, anodizing, etc. It is preferable to perform processing such as rough cutting, centerless grinding, sand blasting, wet honing, and coloring. By roughening the surface on which the photosensitive layer 36 is formed by a surface treatment, the density-like spots of grain due to the interference light in the photosensitive body that can be generated when using a coherent light source such as a laser beam. Can be prevented.

  The undercoat layer 34 has a function of preventing charge injection from the conductive substrate 33 to the photosensitive layer 36 when the photosensitive layer 36 is charged. The undercoat layer 34 also functions as an adhesive layer that integrally adheres and holds the photosensitive layer 36 to the conductive support layer 3. Further, the undercoat layer 34 has a function of preventing light reflection of the conductive substrate 33.

  Materials used for the undercoat layer 34 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; Kokishido 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 34 is made of vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris-2-methoxyethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxy. Propyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-2-aminoethylaminopropyltrimethoxysilane, γ-mercapropropyltrimethoxysilane, γ-ureidopropyltriethoxysilane, It can be used by containing a silane coupling agent such as β-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 undercoat layer 34, metal oxide fine particles can be added. 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 Fine particles of oxide are preferably used. Further, these metal oxide fine particles are more preferably coated with at least one coupling agent, and a silane coupling agent is preferred as the coupling agent.

  In the undercoat layer 34, an electron transporting pigment may be mixed / dispersed. 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, zinc oxide, and titanium oxide are preferably used because of their high electron mobility. Further, the surface of these pigments may be surface-treated with the above-mentioned coupling agent or binder for the purpose of controlling dispersibility and charge transport property. If the amount of the electron transporting pigment is too large, the strength of the undercoat layer 34 is lowered and a coating film defect is caused. Therefore, the amount is 95% by mass or less, preferably 90% by mass or less, based on the total amount of the undercoat layer 34.

  The undercoat layer 34 can also be formed by containing metal oxide fine 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 more preferably used. Examples of the acceptor compound having an anthraquinone structure include hydroxyanthraquinone compounds, aminoanthraquinone compounds, aminohydroxyanthraquinone compounds, and the like in addition to anthraquinones. More specifically, anthraquinone, alizarin, quinizarin, anthralfin, pullpurin and the like are particularly preferably used.

  The amount of these acceptor compounds applied can be arbitrarily set as long as desired properties are obtained, but is preferably 0.01 to 20 parts by mass, more preferably 0.05 to 100 parts by mass of the metal oxide. To 10 parts by mass. If the applied amount is less than 0.01 parts by mass, sufficient acceptor properties that contribute to the improvement of charge accumulation in the undercoat layer 34 cannot be imparted, so that it tends to cause deterioration of maintainability such as an increase in residual potential during repeated use. is there. Further, when the amount exceeds 20 parts by mass, aggregation of metal oxides is likely to occur, and it becomes difficult to form a good conductive path in the undercoat layer 34 when the undercoat layer 34 is formed. Not only does it tend to cause deterioration in sustainability such as an increase in residual potential, but it also tends to cause 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. The method of providing an acceptor compound uniformly to metal oxide fine particles by this is mentioned. When the acceptor compound is added or sprayed, it is preferably carried out at a temperature below the boiling point of the solvent, and if sprayed at a temperature above the boiling point of the solvent, the solvent evaporates before stirring uniformly, and the acceptor compound is localized. It is not preferable because it has a drawback that it is difficult to achieve uniform processing. 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.

The metal oxide fine particles to which the acceptor compound is imparted preferably have a powder resistance (volume resistivity) of about 1 × 10 ² to 1 × 10 ¹¹ Ω · cm. As a result, the undercoat layer 34 can obtain an appropriate resistance for obtaining leak resistance.

  The undercoat layer 34 is formed by applying a coating solution for forming an undercoat layer obtained by mixing / dispersing the components constituting the undercoat layer 34 in an organic solvent onto the conductive substrate 33 and removing the solvent by drying. It is formed by doing.

  A conventional method using a ball mill, a roll mill, a sand mill, an attritor, an ultrasonic wave, or the like is applied as a mixing / dispersing method in preparing the coating liquid for forming the undercoat layer. Mixing / dispersing is carried out in an organic solvent, as long as the organic solvent dissolves an organometallic compound or resin and does not cause gelation or aggregation when an electron transporting pigment is mixed / dispersed. Anything can be used. 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 Ordinary organic solvents such as chlorobenzene and toluene can be used alone or in admixture of two or more.

  As a coating method for the coating solution for forming the undercoat layer, a normal method such as 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, or a curtain coating method should be used. Can do. The coated layer is dried to obtain the undercoat layer 34. Usually, the drying is performed at a temperature at which a solvent can be evaporated and a film can be formed. In particular, the conductive substrate 33 that has been subjected to the acid solution treatment and the boehmite treatment is preferably formed with the undercoat layer 34 because the defect concealing power of the conductive substrate 33 tends to be insufficient.

  The thickness of the undercoat layer 34 formed in this manner is preferably 0.1 to 10 μm, more preferably 0.5 to 5.0 μm when it does not contain metal oxide fine particles. . Moreover, when containing metal oxide microparticles | fine-particles, it is preferable that it is 15 micrometers or more, and it is more preferable that it is 15-50 micrometers. When the thickness of the undercoat layer 34 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.

  The intermediate layer 37 is a layer provided between the undercoat layer 34 and the photosensitive layer 36 in order to improve electrical characteristics, improve image quality, improve image quality maintenance, improve adhesion of the photosensitive layer, and the like.

  As a material used for the intermediate layer 37, similarly to the material used for the undercoat layer 34, 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 Rukokishido 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 34, the intermediate layer 37 is made of vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris-2-methoxyethoxysilane, vinyltriacetoxysilane, γ-glycidoxypropyl. Trimethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, γ-2-aminoethylaminopropyltrimethoxysilane, γ-mercapropropyltrimethoxysilane, Silane coupling agents such as γ-ureidopropyltriethoxysilane and 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 37, as in the case of the undercoat layer 34, 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, zinc oxide, and titanium oxide are preferably used because of their high electron mobility. Further, the surface of these pigments may be surface-treated with the above-mentioned coupling agent or binder for the purpose of controlling dispersibility and charge transport property. If the amount of the electron transporting pigment is too large, the strength of the intermediate layer 37 is lowered and a coating film defect is caused.

  As in the case of the undercoat layer 34, the intermediate layer 37 is formed by applying a coating solution for forming an intermediate layer obtained by mixing / dispersing each component constituting the above-described intermediate layer 37 in an organic solvent onto the undercoat layer 34. It is formed by removing the solvent by drying.

  A conventional method using a ball mill, a roll mill, a sand mill, an attritor, an ultrasonic wave, or the like is applied as a mixing / dispersing method in preparing the intermediate layer forming coating solution. Mixing / dispersing is carried out in an organic solvent, as long as the organic solvent dissolves an organometallic compound or resin and does not cause gelation or aggregation when an electron transporting pigment is mixed / dispersed. Anything can be used. 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 Ordinary organic solvents such as chlorobenzene and toluene can be used alone or in admixture of two or more.

  As a coating method for the intermediate layer forming coating solution, a usual method such as 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, or a curtain coating method may be used. it can. The coated layer is dried to obtain the intermediate layer 37. Usually, the drying is performed at a temperature at which the solvent can be evaporated to form a film.

  The thickness of the intermediate layer 37 formed in this way is preferably 0.1 to 10 μm, and more preferably 0.5 to 5.0 μm. When the thickness of the intermediate layer 37 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 31 is formed by forming a charge generation material by vacuum deposition or by dispersing and applying the charge generation material together with an organic solvent and a binder resin.

  When the charge generation layer 31 is formed by dispersion coating, the charge generation material is dispersed together with an organic solvent, a binder resin, an additive, and the like to prepare a coating liquid for forming a charge generation layer, and the obtained coating liquid is intermediate It can be formed by coating on the layer 37 and drying.

  As the charge generation material, known charge generation materials can be used without particular limitation. As the charge generation material for infrared light, phthalocyanine pigment, squarylium, bisazo, trisazo, perylene, dithioketopyrrolopyrrole, etc. are used, and as the charge generation material for visible light, condensed polycyclic pigment, bisazo, perylene, Trigonal selenium, dye-sensitized zinc oxide fine particles and the like are used. Among these, particularly excellent performance is obtained, and charge generating materials that are preferably used are phthalocyanine pigments and azo pigments. By using these charge generation materials, it is possible to obtain an electrophotographic photosensitive member having particularly high sensitivity and excellent repeatability. In addition, phthalocyanine pigments and azo pigments generally have several crystal types, and any of these crystal types can be used as long as it is a crystal type capable of obtaining electrophotographic characteristics suitable for the purpose. . Particularly preferred charge generating materials include chlorogallium phthalocyanine, dichlorosus phthalocyanine, hydroxygallium phthalocyanine, metal-free phthalocyanine, oxytitanyl phthalocyanine, chloroindium phthalocyanine, and the like.

  In particular, the charge generation layer 31 preferably contains a hydroxygallium phthalocyanine pigment from the viewpoint of obtaining uniform chargeability. As the hydroxygallium phthalocyanine pigment, any pigment can be used as long as it has the desired characteristics. In particular, in the X-ray diffraction spectrum using CuKα characteristic X-ray, the Bragg angle (2θ ± 0.2 °) is 7.5. Those having diffraction peaks at ° and 28.3 ° are preferably used.

  The binder resin used for the charge generation layer 31 can be selected from a wide range of insulating resins. Preferred binder resins include polyvinyl acetal resin, polyarylate resin (polycondensate of bisphenol A and phthalic acid, etc.), polycarbonate resin, polyester resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyamide resin, acrylic resin Insulating resins such as polyacrylamide resin, polyvinyl pyridine resin, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol resin, polyvinyl pyrrolidone resin, poly-N-vinyl carbazole, polyvinyl anthracene, polyvinyl pyrene, polysilane, etc. Organic photoconductive polymers are mentioned. Among these, polyvinyl acetal resin and vinyl chloride-vinyl acetate copolymer are preferably used. These binder resins can be used singly or in combination of two or more.

  The charge generation layer 31 is formed by vacuum deposition of a charge generation material or application of a charge generation layer forming coating solution containing a charge generation material and a binder resin. In the coating solution for forming the charge generation layer, the blending ratio (mass ratio) of the charge generation 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. . The solvent for adjusting the coating solution can be arbitrarily selected from known organic solvents such as alcohols, aromatics, halogenated hydrocarbons, ketones, ketone alcohols, ethers and esters. . More specifically, examples of the solvent include methanol, ethanol, n-propanol, iso-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, acetic acid. Usual organic solvents such as n-butyl, dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, and toluene can be used. These solvents can be used alone or in admixture of two or more. When two or more kinds are mixed, any solvent can be used as long as it can dissolve the binder resin as a mixed solvent.

  As a method for dispersing the charge generation material and the binder resin in a solvent, methods such as a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a colloid mill, and a paint shaker can be used.

  Further, as a coating method used for forming the charge generation layer 31, the blade coating method, the wire bar coating method, the spray coating method, the dip coating method, the bead coating method, the air knife coating method, the curtain coating method and the like are used. The method can be used.

  The thickness of the charge generation layer 31 formed in this way is preferably 0.05 to 5.0 μm, and preferably 0.1 to 1.0 μm, in order to give good electrical characteristics and image quality. Is more preferable. If the thickness of the charge generation layer 31 is less than 0.05 μm, the sensitivity tends to be insufficient. On the other hand, when the thickness of the charge generation layer 31 exceeds 5.0 μm, it tends to cause adverse effects such as poor charging properties.

  Further, the charge generation material used for the charge generation layer 31 can be subjected to a surface treatment in order to improve the stability of electrical characteristics and prevent image quality defects. As the surface treatment agent, a coupling agent, an organic zirconium compound, an organic titanium compound, an organoaluminum compound, and the like can be used, but the surface treatment agent is not limited thereto.

  Examples of coupling agents used for the surface treatment include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycol. Sidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- ( Examples of the silane coupling agent include aminoethyl) -γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, and γ-chloropropyltrimethoxysilane. Particularly preferred silane coupling agents are vinyltriethoxysilane, vinyltris (2-methoxyethoxysilane), 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- (3,4 -Epoxycyclohexyl) ethyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N Examples include silane coupling agents such as phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-chloropropyltrimethoxysilane.

  Examples of the organic zirconium compound include zirconium butoxide, zirconium zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl acetoacetate butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octoate, Zirconium naphthenate, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide and the like.

  Further, as the organic titanium compound, 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 ethyl ester, titanium triethanolamate, polyhydroxy titanium stearate and the like.

  Examples of the organoaluminum compound include aluminum isopropylate, monobutoxyaluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, and aluminum tris (ethyl acetoacetate).

  The charge transport layer 32 includes, for example, a charge transport material and a binder resin. Any known material can be used as the charge transporting material contained in the charge transporting layer 32, such as 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadiazole. Oxadiazole derivatives, pyrazoline derivatives such as 1,3,5-triphenyl-pyrazoline, 1- [pyridyl- (2)]-3- (p-diethylaminostyryl) -5- (p-diethylaminostyryl) pyrazoline, Triphenylamine, tri (P-methyl) phenylamine, N, N′-bis (3,4-dimethylphenyl) biphenyl-4-amine, dibenzylaniline, 9,9-dimethyl-N, N′-di ( p-tolyl) aromatic tertiary amino compounds such as fluorenone-2-amine, N, N′-diphenyl-N, N′-bis (3-methylphenyl)- Aromatic tertiary diamino compounds such as 1,1-biphenyl] -4,4′-diamine, 3- (4′dimethylaminophenyl) -5,6-di- (4′-methoxyphenyl) -1,2 1,2,4-triazine derivatives such as 1,4-triazine, 4-diethylaminobenzaldehyde-1,1-diphenylhydrazone, 4-diphenylaminobenzaldehyde-1,1-diphenylhydrazone, [p- (diethylamino) phenyl] (1 A hydrazone derivative such as -naphthyl) phenylhydrazone, a quinazoline derivative such as 2-phenyl-4-styryl-quinazoline, a benzofuran derivative such as 6-hydroxy-2,3-di (p-methoxyphenyl) -benzofuran, p- (2 , 2-diphenylvinyl) -N, N′-diphenylaniline and other α-stilbene derivatives, Namin derivatives, carbazole derivatives such as N-ethylcarbazole, hole transport materials such as poly-N-vinylcarbazole and its derivatives, quinone compounds such as chloranil, bromoanil, anthraquinone, tetracyanoquinodimethane compounds, 2, 4 , 7-trinitrofluorenone, 2,4,5,7-tetranitro-9-fluorenone and the like, 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4- Oxadiazoles such as oxadiazole, 2,5-bis (4-naphthyl) -1,3,4-oxadiazole, 2,5-bis (4-diethylaminophenyl) 1,3,4 oxadiazole Compounds, xanthone compounds, thiophene compounds, dipheno such as 3,3 ′, 5,5′tetra-t-butyldiphenoquinone Polymer or the like having an electron transport material, such as non-compound, or a compound group shown above in the main chain or side chain. These charge transport materials can be used alone or in combination of two or more.

  Any binder resin can be used as the binder resin used for the charge transport layer 32, but a resin capable of forming an electrically insulating film is preferable. Examples of the binder resin include polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer. Polymer, 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-vinylcarbazole, Polysilanes and polymer charge transport materials such as polyester polymer charge transport materials disclosed in JP-A-8-176293 and JP-A-8-208820 can also be used. Among these, a polycarbonate resin, a polyester resin, a methacrylic resin, and an acrylic resin are preferably used because they are excellent in compatibility with a charge transport material, solubility in a solvent, and strength. 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.

  A polymer charge transport material can also be used alone. As the polymer charge transport material, known materials having charge transport properties such as poly-N-vinylcarbazole and polysilane can be used. In particular, polyester polymer charge transport materials disclosed in JP-A-8-176293 and JP-A-8-208820 have a high charge transporting property and are particularly preferable. The polymer charge transport material alone can be used as the charge transport layer, but it may be formed by mixing with the binder resin.

  The charge transport layer 32 is formed by applying a charge transport layer forming coating solution in which a charge transport substance, a binder resin, and other materials are dissolved in an appropriate solvent on the charge transport layer 31 and drying. Can do. Examples of the solvent used in the coating solution for forming the charge transport layer include aromatic hydrocarbon solvents such as toluene and chlorobenzene, aliphatic alcohol solvents such as methanol, ethanol and n-butanol, acetone, cyclohexanone and 2-butanone. Ketone solvents, halogenated aliphatic hydrocarbon solvents such as methylene chloride, chloroform and ethylene chloride, cyclic or linear ether solvents such as tetrahydrofuran, dioxane, ethylene glycol and diethyl ether, or a mixed solvent thereof. be able to.

  As a coating method when the charge transport layer forming coating solution is coated on the charge generation layer 31, a dip coating method, a push-up coating method, a spray coating method, a roll coater coating method, a wire bar coating method, a gravure coater coating method, A bead coating method, a curtain coating method, a blade coating method, an air knife coating method, or the like can be used.

  The thickness of the charge transport layer 32 is preferably 5 to 50 μm, and more preferably 10 to 40 μm.

  In the electrophotographic photosensitive member, an antioxidant, a light stabilizer, etc. are contained in the photosensitive layer 3 for the purpose of preventing deterioration of the electrophotographic photosensitive member due to ozone or oxidizing gas generated in the image forming apparatus or light or heat. Additives 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.

  Specific examples of antioxidants include phenolic antioxidants such as 2,6-di-t-butyl-4-methylphenol, styrenated phenol, n-octadecyl-3- (3 ′, 5 ′. -Di-t-butyl-4'-hydroxyphenyl) -propionate, 2,2'-methylene-bis- (4-methyl-6-t-butylphenol), 2-t-butyl-6- (3'-t -Butyl-5'-methyl-2'-hydroxybenzyl) -4-methylphenyl acrylate, 4,4'-butylidene-bis- (3-methyl-6-tert-butyl-phenol), 4,4'-thio -Bis- (3-methyl-6-tert-butylphenol), 1,3,5-tris (4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, tetrakis- [methyle -3- (3 ', 5'-di-t-butyl-4'-hydroxy-phenyl) propionate] -methane, 3,9-bis [2- [3- (3-t-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-4piperidyl) 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-lauryl-thiopropionate), 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.

  Organic sulfur-based and organic phosphorus-based antioxidants are said to be secondary antioxidants, and a synergistic effect can be obtained by using them together with primary antioxidants such as phenol-based or amine-based antioxidants.

  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'-di-hydroxy-4-methoxybenzophenone, and the like. 2- (2′-hydroxy-5′methylphenyl) -benzotriazole, 2- [2′-hydroxy-3 ′-(3 ″, 4 ″, 5 ″, 6 ′) as benzotriazole light stabilizer '-Tetrahydrophthalimidomethyl) -5'-methylphenyl] -benzotriazole, 2- (2'-hydroxy-3'-tert-butyl5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'- Hydroxy-3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3 ', 5'-t-butylphenyl) -benzotriazole, 2- (2' -Hydroxy-5'-t-octylphenyl) -benzotriazole, 2- (2'-hydroxy-3 ', 5'-di-t-amylphenyl) -benzotriazole, etc. And the like.

  As other compounds, 2,4-di-t-butylphenyl-3 ', 5'-di-t-butyl-4'-hydroxybenzoate, nickel dibutyl-dithiocarbamate, and the like may be used.

  In addition, at least one kind of electron-accepting substance can be contained for the purpose of improving sensitivity, reducing residual potential, and reducing fatigue during repeated use.

Examples of the electron accepting substance include succinic anhydride, maleic anhydride, dibromomaleic anhydride, phthalic anhydride, tetrabromophthalic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m-dinitrobenzene. , Chloranil, dinitroanthraquinone, trinitrofluorenone, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, phthalic acid and the like. Of these, fluorenone-based, quinone-based, and benzene derivatives having an electron-withdrawing substituent such as Cl, CN, NO ₂ are particularly preferable.

  In particular, as shown in FIGS. 6 and 7, when the charge transport layer 32 is the outermost surface layer, it is preferable to disperse a solid lubricant or a metal oxide in the charge transport layer 32 for the purpose of reducing wear. . Examples of solid lubricants include fluorine-containing resin particles (ethylene tetrafluoride, ethylene trifluoride chloride, ethylene tetrafluoride hexafluoropropylene resin, vinyl fluoride resin, vinylidene fluoride resin, ethylene difluoride dichloride and those And the like, and silicon-containing resin particles. Examples of the metal oxide include silica, alumina, titanium oxide, 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 32 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 small amount of silicone oil can be added to the charge transport layer 32 as a leveling agent for improving the smoothness of the coating film.

  The protective layer 35 is used to prevent chemical change of the charge transport layer 32 during charging, to improve the mechanical strength of the photosensitive layer 36, and to further improve the resistance of the surface layer to abrasion and scratches. .

  Examples of the form of the protective layer 35 include a cured resin film containing a curable resin and a charge transporting compound, a film formed by containing a conductive material in an appropriate binder resin, and the like. What is contained is preferably used. The curable resin can be used without particular limitation as long as it is a known resin, but in particular from the viewpoint of strength, electrical characteristics and image quality maintenance, those having a crosslinked structure are preferable, for example, phenol resin, urethane resin, melamine resin, Examples include diallyl phthalate resin and siloxane resin.

  The charge transporting compound used for the protective layer 35 has a reactive functional group and is preferably compatible with the curable resin used, and further forms a chemical bond with the curable resin used. Those are more preferred. As the charge transport compound having a reactive functional group, a compound represented by the following general formula (I) is preferable.

F [-D-Si (R ¹ ) _(3-a) Q _a ] _b (I)
[In Formula (I), F represents an organic group derived from a compound having a hole transporting ability, D represents a divalent group having flexibility, and R ¹ represents a hydrogen atom, a substituted or unsubstituted group. An alkyl group or a substituted or unsubstituted aryl group, Q represents a hydrolyzable group, a represents an integer of 1 to 3, and b represents an integer of 1 to 4; ]

  In the above general formula (I), F is a unit having photoelectric characteristics, specifically, photocarrier transport characteristics, and a structure conventionally known as a charge transport material can be used as it is. Specifically, compound skeletons having hole transport properties such as triarylamine compounds, benzidine compounds, arylalkane compounds, aryl-substituted ethylene compounds, stilbene compounds, anthracene compounds, hydrazone compounds, and quinones A compound skeleton having an electron transporting property such as a compound, a fluorenone compound, a xanthone compound, a benzophenone compound, a cyanovinyl compound, or an ethylene compound can be used.

In the general formula (I), —Si (R ¹ ) _(3-a) Q _a is a substituted silicon group having a hydrolyzable group, and the substituted silicon undergoes a crosslinking reaction with the Si group. A three-dimensional Si—O—Si bond is formed. That is, this substituted silicon group plays a role of forming a so-called inorganic glassy network in the protective layer 35.

In the above general formula (I), D represents a divalent group having flexibility. Specifically, it is directly bonded to an F site for imparting photoelectric characteristics and a three-dimensional inorganic glassy network. An organic group that plays a role in linking to a substituted silicon group that is tied in, and gives moderate flexibility to an inorganic glassy network that is hard but brittle, and improves the toughness of the film. To express. Specific examples _{D, -C n H 2n -,} - C n H (2n-2) -, - C n H (2n-4) - 2 divalent hydrocarbon group (here represented, n is 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 )-And a characteristic group arbitrarily combining these, and those obtained by substituting structural atoms of these characteristic groups with other substituents.

  In the 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) contains two or more Si atoms, and it becomes easy to form an inorganic glassy network, and mechanical strength is increased. Will improve.

  The F in the compound represented by the general formula (I) is preferably a group represented by the following general formula (II). The group represented by the following general formula (II) is a group having a hole transporting ability, and it is particularly preferable that the protective layer 35 contains this group from the viewpoint of improving the photoelectric characteristics and mechanical characteristics of the protective layer 35.

［式（ＩＩ）中、Ａｒ^１、Ａｒ^２、Ａｒ^３及びＡｒ^４はそれぞれ独立に置換又は未置換のアリール基を示し、Ａｒ^５は置換若しくは未置換のアリール基又はアリーレン基を示し、且つＡｒ^１〜Ａｒ^５のうち１〜４個は、上記一般式（Ｉ）で表わされる化合物における−Ｄ−Ｓｉ（Ｒ^１）_{（３-ａ）}Ｑ_ａで示される部位と結合するための結合手を有し、ｋは０又は１を示す。］

[In formula (II), Ar ¹ , Ar ² , Ar ³ and Ar ⁴ each independently represent a substituted or unsubstituted aryl group, Ar ⁵ represents a substituted or unsubstituted aryl group or arylene group, and Ar ^{1 to} 4 of ^{1 to} Ar ^{5 have} a bond for binding to the site represented by -D-Si (R ¹ ) _(3-a) Q _a in the compound represented by the general formula (I). And k represents 0 or 1. ]

Further, as the substituted or unsubstituted aryl group represented by Ar ^{1 to} Ar ⁴ in the general formula (II), specifically, an aryl group represented by the following general formulas (1) to (7) is preferable. .

The formula (1) ~ ^{(7), R 11} is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkyl group having 1 to 4 carbon atoms, alkoxy group having 1 to 4 carbon atoms, phenyl which is substituted by them A group or an unsubstituted phenyl group, or an aralkyl group having 7 to 10 carbon atoms, wherein R ^{12 to} R ¹⁴ are a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and a carbon number, respectively. 1 to 4 alkoxy groups, phenyl or unsubstituted phenyl groups substituted therewith, aralkyl groups having 7 to 10 carbon atoms or halogen atoms, Ar represents a substituted or unsubstituted arylene group, and X represents the above -D-Si (R ¹ ) _(3-a) in the compound represented by the general formula (I) _(3-a) Q _a represents a structure, c and s each represents 0 or 1, and t represents an integer of 1 to 3. Indicates.

  Moreover, as Ar in the aryl group represented by the above formula (7), an arylene group represented by the following formula (8) or (9) is preferable.

In the above formulas (8) and (9), R ¹⁵ and R ¹⁶ are each substituted with a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and an alkoxy group having 1 to 4 carbon atoms. A phenyl group, an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, or a halogen atom, and t represents an integer of 1 to 3.

  Moreover, as Z 'in the aryl group represented by the above formula (7), divalent groups represented by the following formulas (10) to (17) are preferable.

In the above formulas (10) to (17), R ¹⁷ and R ¹⁸ are each substituted with a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, and an alkoxy group having 1 to 4 carbon atoms. A phenyl group, an unsubstituted phenyl group, an aralkyl group having 7 to 10 carbon atoms, or a halogen atom, W represents a divalent group, q and r each represent an integer of 1 to 10, and t Represents an integer of 1 to 3, respectively.

  In the above formulas (16) to (17), W represents a divalent group represented by the following formulas (18) to (26). In formula (25), u represents an integer of 0 to 3.

In addition, the specific structure of Ar ⁵ in the general formula (II) includes the aryl groups exemplified as the specific structure of Ar ^{1 to} Ar ⁴ when k is 0, and the case where k is 1 An arylene group obtained by removing a predetermined hydrogen atom from an aryl group is exemplified.

  The charge transporting compound represented by the general formula (I) may be used alone or in combination of two or more.

  In addition to the charge transporting compound represented by the above general formula (I), the protective layer 35 includes 2 as represented by the following general formula (III) for the purpose of further improving the mechanical strength of the cured film. It is also preferable to use a compound having two or more silicon atoms.

B (—Si (R ⁴⁰ ) _(3-a) Q _a ) _d (III)
[In Formula (III), B represents a divalent or higher organic group, R ⁴⁰ represents a hydrogen atom, an alkyl group, or a substituted or unsubstituted aryl group, Q represents a hydrolyzable group, and a represents 1 to 1 3 represents an integer, and d 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 —Si (R ⁴⁰ ) _(3-a) Q _a . The compound represented by the general formula (III) has a Si—O—Si bond formed by a reaction with the compound represented by the general formula (I) or a reaction between the compounds represented by the general formula (III). Form a three-dimensional cross-linked cured film. 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 appropriate flexibility is imparted to the cured film. Therefore, stronger mechanical strength can be obtained. Preferable examples of the compound represented by the general formula (III) include the following compounds (III-1) to (III-19). In the following table, Me represents a methyl group, Et represents an ethyl group, and Pr represents a propyl group.

  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, commercially available silicone hard coat agents, and the like can be used.

  Examples of the silane coupling agent include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-glycidoxypropyl. Trimethoxysilane, γ-aminopropyltriethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropylmethyldimethoxysilane, N-β (aminoethyl) γ-aminopropyltriethoxysilane, tetramethoxysilane, methyltrimethoxy Examples thereof include silane and dimethyldimethoxysilane.

  As a commercially available hard coat agent, KP-85, CR-39, X-12-2208, X-40-9740, X-41-1007, KNS-5300, X-40-2239 (above, manufactured by Shin-Etsu Silicone Co., Ltd.) ), AY42-440, AY42-441, AY49-208 (manufactured by Toray Dow Corning), and the like.

  Further, a fluorine atom-containing compound can be added to the protective layer 35 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 the effect of preventing the adhesion of discharge products, developer, paper dust, etc. to the surface of the electrophotographic photosensitive member, which is useful for improving the life of the electrophotographic photosensitive member.

  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 where the protective layer 35 is a cured film formed of the compound represented by the general formula (I), a fluorine-containing compound that can react with an alkoxysilane is added to constitute a part of the crosslinked film. Is desirable. Specific examples of such a fluorine atom-containing compound include (tridecafluoro-1,1,2,2-tetrahydrooctyl) triethoxysilane, (3,3,3-trifluoropropyl) trimethoxysilane, 3- (Heptafluoroisopropoxy) propyltriethoxysilane, 1H, 1H, 2H, 2H-perfluoroalkyltriethoxysilane, 1H, 1H, 2H, 2H-perfluorodecyltriethoxysilane, 1H, 1H, 2H, 2H-per And fluorooctyltriethoxysilane.

  The content of the fluorine-containing compound is preferably 20% by mass or less based on the total amount of the protective layer 35. If the content exceeds 20% by mass, there may be a problem in the film formability of the crosslinked cured film.

  The protective layer 35 has sufficient oxidation resistance, but 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. You may use well-known antioxidants, such as. The addition amount of the antioxidant is preferably 15% by mass or less, more preferably 10% by mass or less, based on the total amount of the protective layer 35.

  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-hydroxy-benzylphosphonate-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-t-butylphenol), 2,5-di-t-amylhydroquinone, 2-t-butyl-6- (3-butyl-2- Dorokishi-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 35, 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 35 can be formed by applying a coating solution for forming a protective layer containing the above-described various materials and various additives onto the photosensitive layer 36 and subjecting it to a heat treatment. Thereby, the compound etc. which are represented with the said 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 underlying photosensitive layer 36, but is preferably room temperature to 200 ° C, more preferably 100 to 160 ° C.

  In the formation of the protective layer 35, the crosslinking and 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 and trifluoroacetic acid, bases such as ammonia and triethylamine, organotin compounds such as dibutyltin diacetate, dibutyltin dioctoate and stannous oxalate, tetra -Organic titanium compounds such as -n-butyl titanate and tetraisopropyl titanate, iron salts, manganese salts, cobalt salts, zinc salts, zirconium salts and aluminum chelate compounds of organic carboxylic acids.

  In order to make application | coating easy, the solvent can be added to the coating liquid for protective layer formation as needed. Specific examples of the solvent include 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, Examples include ordinary organic solvents such as tetrahydrofuran, methylene chloride, chloroform, dimethyl ether, dibutyl ether and the like. These can be used individually by 1 type or in mixture of 2 or more types.

  In the formation of the protective layer 35, the application method of the coating liquid for forming the protective layer includes blade coating method, wire bar coating method, spray coating method, dip coating method, bead coating method, air knife coating method, curtain coating method, etc. Conventional methods can be used.

  The thickness of the protective layer 35 thus formed is preferably 0.5 to 20 μm, and more preferably 2 to 10 μm.

  As shown in FIG. 10, when the photosensitive layer is a single-layer type photosensitive layer 38, the single-layer type photosensitive layer 38 is formed containing a charge generation material, a charge transport material, and a binder resin. The charge generation material is the same as that used for the charge generation layer 31 in the functional separation type photosensitive layer, and the charge transport material is the same as that used for the charge transport layer 32 in the function separation type photosensitive layer. As the binder resin, the same binder resin used for the charge generation layer 31 and the charge transport layer 32 in the function-separated type photosensitive layer can be used. Moreover, the solvent and coating method used for coating can be the same as those for the above layers. The thickness of the single-layer type photosensitive layer 38 is preferably about 5 to 50 μm, and more preferably 10 to 40 μm.

  Next, the image forming apparatus of the present invention will be described with reference to the drawings. FIG. 11 is a sectional view schematically showing a basic configuration of a preferred embodiment of the image forming apparatus of the present invention. The image forming apparatus 200 shown in FIG. 11 is charged by the electrophotographic photosensitive member 207 described above, the charging device 208 that charges the electrophotographic photosensitive member 207, the power source 209 connected to the charging device 208, and the charging device 208. An exposure device 210 that exposes the electrophotographic photosensitive member 207 to form an electrostatic latent image, a developing device 211 that develops the electrostatic latent image formed by the exposure device 210 with toner, and forms a toner image; The image forming apparatus includes a transfer device 212 that transfers a toner image formed by the developing device 211 to a transfer medium (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.

  Here, the charging device 208 is of a type (contact charging type) in which the surface of the electrophotographic photoreceptor 207 is brought into contact with the above-described charging roll of the present invention as a conductive member to charge the surface of the photoreceptor 207. It is.

  When charging the photoreceptor using the charging roll of the present invention, a voltage is applied to the charging roll. The applied voltage may be a DC voltage or a DC voltage superimposed with an AC voltage.

  As the exposure apparatus 210, an optical system apparatus 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.

  As the developing device 211, a conventionally known developing device using a regular or reversal developer such as a one-component system or a two-component system can be used.

  The toner used for the developing device 211 includes, for example, a binder resin and a colorant. Examples of the binder resin include homopolymers and copolymers such as styrenes, monoolefins, vinyl esters, α-methylene aliphatic monocarboxylic acid esters, vinyl ethers, and vinyl ketones. Typical binder resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer. Examples thereof include coalescence, polyethylene, and polypropylene. Furthermore, polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, paraffin wax, and the like can also be mentioned.

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

  The toner may be internally added or externally added with a known additive such as a charge control agent, a release agent, or other inorganic fine particles.

  Typical examples of the release agent include low molecular weight polyethylene, low molecular weight polypropylene, Fischer-Tropsch wax, montan wax, carnauba wax, rice wax, and candelilla wax.

  Known charge control agents can be used, but charge control agents such as azo-based metal complex compounds, metal complex compounds of salicylic acid, and resin types containing polar groups can be used.

  As other inorganic fine particles, small-diameter inorganic fine particles having an average primary particle size of 40 nm or less are used for the purpose of powder flowability, charge control, etc., and if necessary, larger diameters are used to reduce adhesion. Inorganic or organic fine particles may be used in combination. As these other inorganic fine particles, known ones can be used.

  In addition, the small-diameter inorganic fine particles are effective because surface dispersibility increases dispersibility and increases the powder flowability.

  As a method for producing the toner used in the present invention, a polymerization method such as an emulsion polymerization aggregation method or a dissolution suspension method is preferably used because high shape controllability can be obtained. In addition, a manufacturing method may be performed in which the toner obtained by the above method is used as a core, and agglomerated particles are further adhered and heat-fused to give a core-shell structure. When an external additive is added, it can be produced by mixing the toner and the external additive with a Henschel mixer or a V blender. Further, when the toner is manufactured by a wet method, it can be externally added by a wet method.

  Examples of the transfer device 212 include a roller-type contact charging member, a contact-type transfer charger using a belt, a film, a rubber blade, or the like, or a scorotron transfer charger or a corotron transfer charger using corona discharge. It is done.

  The transfer device 212 can supply a current having a predetermined current density to the electrophotographic photosensitive member when the toner image formed on the electrophotographic photosensitive member 207 is transferred to the transfer medium 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.

  The image forming apparatus of the present invention may further include an erase light irradiation device 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. 12 is a cross-sectional view schematically showing a basic configuration of another preferred embodiment of the image forming apparatus of the present invention. The image forming apparatus 210 shown in FIG. 12 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 medium (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. 12, the image forming apparatus 210 may further include a static eliminator in the same manner as 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.

  In such an image forming apparatus 210, when the toner image formed on the electrophotographic photosensitive member 207 is transferred to the primary transfer member 212a, a predetermined current density from the primary transfer member 212a toward the electrophotographic photosensitive member 207 is obtained. By supplying this current, 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 photosensitive member 207 can be accurately controlled. Become. As a result, it is possible to achieve higher image quality and reduced environmental burden at a higher level.

  FIG. 13 is a cross-sectional view schematically showing a basic configuration of another preferred embodiment of the image forming apparatus of the present invention. An image forming apparatus 220 shown in FIG. 13 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. Here, the electrophotographic photoreceptors 401a to 401d mounted on the image forming apparatus 220 are the electrophotographic photoreceptors described above.

  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 of black, yellow, magenta, and cyan 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. Here, the charging rolls 402a to 402d mounted on the image forming apparatus 220 are the above-described charging rolls of the present invention.

  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.

  The intermediate transfer belt 409 is supported with a predetermined tension by a drive roll 406, a backup roll 408, and a tension 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 backup roll 408 via the intermediate transfer belt 409. The intermediate transfer belt 409 passing between the backup 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. Conventionally known resins can be used as the resin material used as the base material of the intermediate transfer member in the belt shape. For example, polyimide resin, polycarbonate resin (PC), polyvinylidene fluoride (PVDF), polyalkylene terephthalate (PAT), ethylenetetrafluoroethylene copolymer (ETFE) / PC, ETFE / PAT, PC / PAT blend material, polyester Resin materials such as polyether ether ketone and polyamide, and resin materials using these as main raw materials. Furthermore, a resin material and an elastic material can be blended and used.

  As an elastic material, polyurethane, chlorinated polyisoprene, NBR, chloropyrene rubber, EPDM, hydrogenated polybutadiene, butyl rubber, silicone rubber, or the like can be used, or a material obtained by blending two or more kinds can be used. If necessary, a conductive agent imparting electronic conductivity or a conductive agent having ionic conductivity is added to the resin material and elastic material used for these base materials in combination of one kind or two or more kinds. Among these, it is preferable to use a polyimide resin in which a conductive agent is dispersed from the viewpoint of excellent mechanical strength. As the conductive agent, a conductive polymer such as carbon black, metal oxide, or polyaniline can be used.

  When a belt-shaped configuration such as the intermediate transfer belt 409 is employed as the intermediate transfer member, the thickness of the belt is generally preferably 50 to 500 μm and more preferably 60 to 150 μm, but is appropriately selected according to the hardness of the material. be able to.

  For example, a belt made of a polyimide resin in which a conductive agent is dispersed is 5 to 20% by mass as a conductive agent in a polyamic acid solution, which is a polyimide precursor, as described in JP-A-63-311263. After the carbon black is dispersed, the dispersion is cast on a metal drum and dried, and then the film peeled off from the drum is stretched at a high temperature to form a polyimide film. Can be produced.

  The film molding is generally performed by injecting a polyamic acid solution film-forming stock solution in which a conductive agent is dispersed into a cylindrical mold and, for example, heating at 100 to 200 ° C. at a rotational speed of 500 to 2000 rpm. The film was formed into a film by a centrifugal molding method while rotating, and then the obtained film was demolded in a semi-cured state and covered with an iron core. It can be carried out by proceeding a ring-closing reaction) and carrying out main curing. In addition, the stock solution is cast on a metal sheet to a uniform thickness and heated to 100 to 200 ° C. to remove most of the solvent in the same manner as described above, and then gradually raised to a high temperature of 300 ° C. or higher. There is also a method of forming a polyimide film. The intermediate transfer member may have a surface layer.

  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.

  FIG. 14 is a sectional view schematically showing a preferred embodiment of the process cartridge of the present invention. The process cartridge 300 includes an electrophotographic photosensitive member 207, a developing device 211, a cleaning device (cleaning means) 213, an opening 218 for exposure, and static elimination exposure as well as the above-described charging device 208 having the charging roll of the present invention. The opening 217 is combined and integrated using the mounting rail 216.

  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.

  In the image forming apparatus and the process cartridge of the present invention described above, since the charging roll of the present invention is used, good charging characteristics are maintained over a long period of time, and an image with good image quality can be stably formed. it can.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to a following example.

<Example 1>
An adhesive (KBE-903, manufactured by Shin-Etsu Chemical Co., Ltd.) is applied by brush to a cylindrical conductive support with a diameter of 8 mm, which is nickel-plated and chromated on a SUM material (free-cutting steel), and air-dried. It was. Next, as a rubber material, liquid silicone rubber (LSR) containing carbon black (manufactured by Shin-Etsu Chemical Co., Ltd., ASKER-C hardness: 30) is used, and the conductivity is applied by the injection molding method. An elastic layer was formed on the support to obtain a conductive elastic roll A1. At this time, the elastic layer was formed using a mold so that the conductive elastic roll A1 was an A3 size roll having a diameter of 14 mm and a rubber length of 320 mm.

  Next, an adhesive (DY39−) is formed on both ends of the conductive elastic roll A1 on the elastic layer (both ends in the axial direction of the conductive elastic roll A1) with a width of 10 mm from both ends of the conductive elastic roll A1. 067, manufactured by Toray Dow Corning Co., Ltd.) was applied by brush and allowed to air dry to form an adhesive layer. Thereby, electroconductive elastic roll A2 was obtained.

  Next, 100 parts by mass of a polyurethane resin solution (Nipporan 3113, manufactured by Nippon Polyurethane Industry Co., Ltd.), 10 parts by mass of an isocyanate solution (Coronate 2507, manufactured by Nippon Polyurethane Industry Co., Ltd.) as a curing agent, and carbon black (MONARCH1000 as a conductive agent) (Manufactured by Cabot Co., Ltd.) 27 parts by mass of dispersion in a bead mill was added to 50 parts by mass of MEK and diluted to obtain a coating solution for forming a resistance layer. The obtained coating solution was dip-coated on the surface of the conductive elastic roll A2, and then heated and dried at 180 ° C. for 60 minutes to form a 300 μm-thick resistance layer to obtain a conductive elastic roll A3.

  Next, 100 parts by mass of copolymer nylon (Alamine CM8000, manufactured by Toray Industries, Inc.) as a polymer material, 30 parts by mass of antimony-doped tin oxide (SN-100P, manufactured by Ishihara Sangyo Co., Ltd.), 500 parts by mass of methanol, and To a dispersion obtained by dispersing 240 parts by weight of butanol with a bead mill, 750 parts by weight of methanol was added and diluted to obtain a coating solution for forming a surface layer. The obtained coating solution was dip-coated on the surface of the conductive elastic roll A3 and then dried by heating at 140 ° C. for 15 minutes to form a surface layer having a thickness of 5 μm to obtain a charging roll.

<Example 2>
In the same manner as in Example 1, an elastic layer was formed on the conductive support to obtain a conductive elastic roll B1. Next, 100 parts by mass of an adhesive (DY39-067, manufactured by Toray Dow Corning) and 1 part by mass of a conductive agent (Ketjen Black EC, manufactured by Lion) are dispersed by a ball mill, and a coating solution for forming an adhesive layer is prepared. Obtained. The adhesive layer forming coating liquid is applied to both end portions on the elastic layer of the conductive elastic roll B1 (both axial end portions of the conductive elastic roll B1) with a width of 10 mm from both ends to the inside of the conductive elastic roll B1. The adhesive layer was formed by applying by brushing and air drying. Thereby, the conductive elastic roll B2 was obtained.

  Next, a resistance layer was formed on the conductive elastic roll B2 in the same manner as in Example 1 to obtain a conductive elastic roll B3. Further, a surface layer was formed on the conductive elastic roll B3 in the same manner as in Example 1 to obtain a charging roll.

<Example 3>
An adhesive (KBE-903, manufactured by Shin-Etsu Chemical Co., Ltd.) is applied by brush to a cylindrical conductive support with a diameter of 8 mm, which is nickel-plated and chromated on a SUM material (free-cutting steel), and air-dried. It was. Next, as a rubber material, liquid silicone rubber (LSR) containing carbon black (manufactured by Shin-Etsu Chemical Co., Ltd., ASKER-C hardness: 32) is used, and the conductivity is applied by the injection molding method. An elastic layer was formed on the support to obtain a conductive elastic roll C1. At this time, the elastic layer was formed using a mold so that the conductive elastic roll C1 was an A3 size roll having a diameter of 14 mm and a rubber length of 320 mm.

  Next, an adhesive layer was formed on the conductive elastic roll C1 in the same manner as in Example 1 to obtain a conductive elastic roll C2. Next, a resistance layer was formed on the conductive elastic roll C2 in the same manner as in Example 1 to obtain a conductive elastic roll C3. Further, a surface layer was formed on the conductive elastic roll C3 in the same manner as in Example 1 to obtain a charging roll.

<Example 4>
In the same manner as in Example 3, an elastic layer was formed on the conductive support to obtain a conductive elastic roll D1. Next, an adhesive layer was formed on the conductive elastic roll D1 in the same manner as in Example 2 to obtain a conductive elastic roll D2. Next, a resistance layer was formed on the conductive elastic roll D2 in the same manner as in Example 1 to obtain a conductive elastic roll D3. Further, a surface layer was formed on the conductive elastic roll D3 in the same manner as in Example 1 to obtain a charging roll.

<Example 5>
In the same manner as in Example 1, an elastic layer was formed on the conductive support to obtain a conductive elastic roll E1. Next, an adhesive (DY39-067) having a width of 10 mm inside from one end of the conductive elastic roll E1 to one end on the elastic layer in the conductive elastic roll E1 (one axial end of the conductive elastic roll E1). , Manufactured by Toray Dow Corning Co., Ltd.) was applied by brushing and air-dried to form an adhesive layer. Thereby, the electroconductive elastic roll E2 was obtained.

  Next, a resistance layer was formed on the conductive elastic roll E2 in the same manner as in Example 1 to obtain a conductive elastic roll E3. Further, a surface layer was formed on the conductive elastic roll E3 in the same manner as in Example 1 to obtain a charging roll.

<Example 6>
A SUM material (free-cutting steel material) nickel-plated and chromate-treated on a cylindrical conductive support with a diameter of 8 mm, 100 parts by mass of a polyolefin-based adhesive (Chemok 250X, manufactured by Road Far East) and a conductive agent (ket An adhesive composition in which 3.0 parts by mass of Chain Black EC (manufactured by Lion Corporation) was dispersed with a ball mill for 24 hours was applied by brush and allowed to air dry.

  Next, 100 parts by mass of epichlorohydrin-ethylene oxide-allyl glycidyl ether copolymer rubber (Gechron 3106, manufactured by Nippon Zeon Co., Ltd.) as a rubber material, 12 parts by mass of carbon black (Asahi Thermal, manufactured by Asahi Carbon Co., Ltd.), a conductive agent (Ketjen Black EC, manufactured by Lion) 5 parts by mass, 1 part by mass of lithium perchlorate as an ionic conductive agent, 1 part by mass of sulfur as a vulcanizing agent (200 mesh, manufactured by Tsurumi Chemical Co., Ltd.), vulcanization acceleration Agent (Noxeller DM, manufactured by Ouchi Shinsei Chemical Co., Ltd.) 2.0 parts by mass, vulcanization accelerator (Noxeller TT, manufactured by Ouchi New Chemical Co., Ltd.) 0.5 parts by mass, zinc dimethyldithiocarbamate (Noxeller PZ, positive (Made by the same chemical industry) 5 parts by mass and 1.5 parts by mass of stearic acid are kneaded with an open roll to form an elastic layer It was obtained. Using the obtained composition, an elastic layer was formed on a conductive support coated with the adhesive so as to form a roll having a diameter of 15 mm and a rubber length of 320 mm by a press molding machine. Thereafter, the elastic layer was polished to obtain a conductive elastic roll F1 having a diameter of 14 mm.

  Next, a polyolefin-based adhesive (with a width of 10 mm from the both ends of the conductive elastic roll F1 to the inside on both ends on the elastic layer of the conductive elastic roll F1 (both ends in the axial direction of the conductive elastic roll F1) ( Chemlok 250X (manufactured by Road Far East) was applied by brushing and air-dried to form a 20 μm thick adhesive layer. Thereby, the electroconductive elastic roll F2 was obtained. Further, a surface layer was formed on the conductive elastic roll F2 in the same manner as in Example 1 to obtain a charging roll.

<Example 7>
In the same manner as in Example 1, an elastic layer was formed on the conductive support to obtain a conductive elastic roll G1. Next, an adhesive (DY39-) is formed on both ends of the conductive elastic roll G1 on the elastic layer (both ends in the axial direction of the conductive elastic roll G1) with a width of 50 mm inside from both ends of the conductive elastic roll G1. 067, manufactured by Toray Dow Corning Co., Ltd.) was applied by brush and allowed to air dry to form an adhesive layer. Thereby, the electroconductive elastic roll G2 was obtained.

  Next, a resistance layer was formed on the conductive elastic roll G2 in the same manner as in Example 1 to obtain a conductive elastic roll G3. Further, a surface layer was formed on the conductive elastic roll G3 in the same manner as in Example 1 to obtain a charging roll.

<Example 8>
An adhesive (KBE-903, manufactured by Shin-Etsu Chemical Co., Ltd.) is applied by brush to a cylindrical conductive support with a diameter of 8 mm, which is nickel-plated and chromated on a SUM material (free-cutting steel), and air-dried. It was. Next, as a rubber material, liquid silicone rubber (LSR) containing carbon black (manufactured by Shin-Etsu Chemical Co., Ltd., ASKER-C hardness: 30) is used, and the conductivity is applied by the injection molding method. An elastic layer was formed on the support to obtain a conductive elastic roll H1. At this time, the elastic layer was formed using a mold so that the conductive elastic roll H1 was an A3 size roll having a diameter of 14 mm and a rubber length of 320 mm.

  Next, an adhesive layer was formed on the conductive elastic roll H1 in the same manner as in Example 1 to obtain a conductive elastic roll H2. Next, a resistance layer was formed on the conductive elastic roll H2 in the same manner as in Example 1 to obtain a conductive elastic roll H3. Further, a surface layer was formed on the conductive elastic roll H3 in the same manner as in Example 1 to obtain a charging roll.

<Example 9>
In the same manner as in Example 1, an elastic layer was formed on the conductive support to obtain a conductive elastic roll I1. Next, 100 parts by mass of an adhesive (DY39-067, manufactured by Toray Dow Corning) and 2 parts by mass of a conductive agent (Ketjen Black EC, manufactured by Lion) are dispersed by a ball mill, and a coating solution for forming an adhesive layer is prepared. Obtained. The adhesive layer forming coating liquid is applied to both ends on the elastic layer of the conductive elastic roll I1 (both ends in the axial direction of the conductive elastic roll I1) with a width of 10 mm from both ends to the inside of the conductive elastic roll I1. The adhesive layer was formed by applying by brushing and air drying. Thereby, the electroconductive elastic roll I2 was obtained.

  Next, a resistance layer was formed on the conductive elastic roll I2 in the same manner as in Example 1 to obtain a conductive elastic roll I3. Further, a surface layer was formed on the conductive elastic roll I3 in the same manner as in Example 1 to obtain a charging roll.

<Comparative Example 1>
In the same manner as in Example 1, an elastic layer was formed on the conductive support to obtain a conductive elastic roll a1. Next, a conductive elastic roll a2 was obtained in the same manner as in Example 1 except that the adhesive layer was formed on the entire surface of the conductive elastic roll a1.

  Next, a resistance layer was formed on the conductive elastic roll a2 in the same manner as in Example 1 to obtain a conductive elastic roll a3. Further, a surface layer was formed on the conductive elastic roll a3 in the same manner as in Example 1 to obtain a charging roll.

<Comparative example 2>
In the same manner as in Example 1, an elastic layer was formed on the conductive support to obtain a conductive elastic roll b1. Next, a resistance layer was formed on the conductive elastic roll b1 in the same manner as in Example 1 to obtain a conductive elastic roll b2. Further, a surface layer was formed on the conductive elastic roll b2 in the same manner as in Example 1 to obtain a charging roll.

<Comparative Example 3>
In the same manner as in Example 1, an elastic layer was formed on the conductive support to obtain a conductive elastic roll c1. Next, a conductive elastic roll c2 was obtained in the same manner as in Example 9 except that the adhesive layer was formed on the entire surface of the conductive elastic roll c1.

  Next, a resistance layer was formed on the conductive elastic roll c2 in the same manner as in Example 1 to obtain a conductive elastic roll c3. Further, a surface layer was formed on the conductive elastic roll c3 in the same manner as in Example 1 to obtain a charging roll.

[Evaluation of charging roll]
For the charging rolls obtained in Examples 1 to 9 and Comparative Examples 1 to 3, the volume resistivity of the elastic layer and the adhesive layer was measured by the method described above with reference to FIG. Further, the charging roll resistance was measured by the method described above. These results are shown in Tables 6-7.
In addition, the charging rolls obtained in Examples 1 to 9 and Comparative Examples 1 to 3 were each modified with a color copier DocuCenter Color a450 manufactured by Fuji Xerox Co., Ltd. And an image forming apparatus was manufactured. Using this image forming apparatus, 30,000 sheets of images were formed on an A3 size image having an image density of 5% in an environment of low temperature and low humidity (10 ° C., 20% RH), and then high temperature and high humidity ( 30,000 sheets of images were formed in an environment of 28 ° C. and 75% RH. After image formation of a total of 60,000 sheets, white paper and 50% half-tone images are printed in A3 size under high and high humidity and low and low humidity environments. Evaluation was performed according to the following evaluation criteria. By confirming the presence or absence of high density areas and fogging in the formed image, it is possible to determine whether or not charging unevenness or surface potential decrease has occurred. The evaluation results are shown in Tables 6-7.
A: Charging unevenness does not occur,
B: Minor charging unevenness occurred,
C: Some uneven charging occurs,
D: Generation of uneven charging,
E: Charging unevenness and photoreceptor surface potential decrease occurred.

In addition, after forming a total of 60,000 images, the surface of the charging roll was observed and evaluated according to the following evaluation criteria in order to evaluate the adhesion between the elastic layer and the upper layer. The evaluation results are shown in Tables 6-7.
A: No wrinkle on the surface,
B: Minor wrinkle generation in part,
C: Minor wrinkle generation on the surface,
D: Wrinkles occur in part,
E: Wrinkles generated on the surface.

Further, after forming a total of 60,000 images, in the region where the adhesive layer is formed, a cut is made with the cutter from the surface of the charging roll until it reaches the elastic layer, and from the elastic layer of the charging roll above it. A test was conducted to peel the layers by hand. The peeled state at this time was evaluated according to the following evaluation criteria, and the adhesion between the elastic layer and the upper layer was evaluated. The evaluation results are shown in Tables 6-7.
A: Good adhesion (the elastic layer breaks without peeling between the elastic layer and the upper layer),
B: Adhesiveness is good (the elastic layer is mostly broken without peeling between the elastic layer and the upper layer),
C: Good adhesion (partially peeled between the elastic layer and the upper layer),
D: Adhesive failure (can be easily peeled between the elastic layer and the upper layer).

  As is apparent from the results shown in Tables 6 to 7, according to the charging rolls of the present invention (Examples 1 to 8), compared to the charging rolls of Comparative Examples 1 to 3, the elastic layer and the elastic layer Adhesion and adhesion with the functional layer formed on the surface are good, occurrence of peeling is sufficiently suppressed, charging unevenness is suppressed over a long period of time, and good charging characteristics can be maintained. It was confirmed that it was possible. Further, in the charging roll of Example 9, the adhesiveness was not always sufficient, but the charging unevenness was sufficiently suppressed, and it was confirmed that good charging characteristics can be maintained.

1 is a perspective view showing a preferred embodiment of a charging roll of the present invention. It is a schematic cross section along the II line of FIG. It is a schematic cross section along the II-II line of FIG. It is a schematic cross section along the III-III line of FIG. It is a schematic diagram for demonstrating the measuring method of the volume resistivity of each layer which comprises the charging roll of this invention. 1 is a schematic cross-sectional view showing an example of an electrophotographic photosensitive member used in the image forming apparatus of the present invention. It is a schematic cross-sectional view showing another example of an electrophotographic photosensitive member used in the image forming apparatus of the present invention. It is a schematic cross-sectional view showing another example of an electrophotographic photosensitive member used in the image forming apparatus of the present invention. It is a schematic cross-sectional view showing another example of an electrophotographic photosensitive member used in the image forming apparatus of the present invention. It is a schematic cross-sectional view showing another example of an electrophotographic photosensitive member used in the image forming apparatus of the present invention. 1 is a cross-sectional view schematically showing a basic configuration of a preferred embodiment of an image forming apparatus of the present invention. It is sectional drawing which shows schematically the basic composition of other suitable one Embodiment of the image forming apparatus of this invention. It is sectional drawing which shows schematically the basic composition of other suitable one Embodiment of the image forming apparatus of this invention. 1 is a cross-sectional view schematically showing a preferred embodiment of a process cartridge of the present invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Conductive support body, 2 ... Elastic layer, 3 ... Adhesive layer, 4 ... Resistance layer (functional layer), 5 ... Surface layer, 10 ... Charge roll, 11 ... Sheet sample, 13 ... High resistance measuring device, 14, DESCRIPTION OF SYMBOLS 15, 16 ... Electrode, 21 ... Ammeter, 22 ... Power supply, 31 ... Charge generation layer, 32 ... Charge transport layer, 33 ... Conductive substrate, 34 ... Undercoat layer, 35 ... Protective layer, 36 ... Photosensitive layer, 37 ... Intermediate layer, 38 ... Single layer type photosensitive layer, 100, 110, 120, 130, 140 ... Electrophotographic photosensitive member, 200, 210,220 ... Image forming device, 207 ... Electrophotographic photosensitive member, 208 ... Charging device, 209 DESCRIPTION OF SYMBOLS ... Power supply 210 ... Exposure device 211 ... Development device 212 ... Transfer device 213 Cleaning device 214 ... Static eliminator 215 ... Fixing device 216 ... Mounting rail 217 ... Opening for static elimination exposure, 218 ... Opening for exposure, 3 DESCRIPTION OF SYMBOLS 0 ... Process cartridge, 400 ... Housing, 401a-401d ... Electrophotographic photosensitive member, 402a-402d ... Charging roll, 403 ... Laser light source (exposure device), 404a-404d ... Developing device, 405a-405d ... Toner cartridge, 406 ... Drive roll, 407 ... tension roll, 408 ... backup roll, 409 ... intermediate transfer belt, 410a to 410d ... primary transfer roll, 411 ... tray (transfer tray), 412 ... transfer roll, 413 ... secondary transfer roll, 414: fixing roll, 415a to 415d: cleaning blade, 416: cleaning blade, 500: medium to be transferred.

Claims (3)

A conductive support, an elastic layer formed on the conductive support, and a functional layer formed on the elastic layer;
The charging roll, wherein the elastic layer and the functional layer are bonded via an adhesive layer formed on at least one end in the charging roll axial direction on the elastic layer. A charging means having a charging roll for charging the electrophotographic photosensitive member by a contact charging method;
The electrophotographic photosensitive member, a developing means for developing the electrostatic latent image formed on the electrophotographic photosensitive member with toner to form a toner image, and the toner remaining on the surface of the electrophotographic photosensitive member are removed. At least one selected from the group consisting of cleaning means for
With
The charging roll has a conductive support, an elastic layer formed on the conductive support, and a functional layer formed on the elastic layer, and the elastic layer and the functional layer include The process cartridge is bonded through an adhesive layer formed on at least one end in the charging roll axial direction on the elastic layer. An electrophotographic photoreceptor;
Charging means having a charging roll for charging the electrophotographic photosensitive member by a contact charging method;
Exposure means for forming an electrostatic latent image on the charged electrophotographic photosensitive member;
Developing means for developing the electrostatic latent image with toner to form a toner image;
Transfer means for transferring the toner image from the electrophotographic photosensitive member to a transfer target;
With
The charging roll has a conductive support, an elastic layer formed on the conductive support, and a functional layer formed on the elastic layer, and the elastic layer and the functional layer include An image forming apparatus, wherein the image forming apparatus is bonded via an adhesive layer formed on at least one end in the charging roll axial direction on the elastic layer.

Images