JP2012203023A - Electrophotographic photoreceptor, image forming apparatus and process cartridge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor having high wear resistance and good electric characteristics, suppressing deterioration of a cleaning blade, and capable of maintaining good cleaning property and prevention of frictional noise between the cleaning blade and the electrophotographic photoreceptor for a long period of time.SOLUTION: The electrophotographic photoreceptor includes at least a photosensitive layer (a charge generating layer (25) and a charge transporting layer (26)) and a surface layer (28) on a conductive support (21). When an axial surface profile of the electrophotographic photoreceptor measured by a contour curve method is processed to obtain a waviness curve by removing a rough component by a λc contour curve filter at a cutoff value of 2.5 mm and by removing a wavelength component longer than the waviness by a λf contour line filter at a cutoff value of 8.0 mm, the obtained waviness curve has an arithmetic average waviness Wa ranging from 0.08 μm to 0.20 μm and an average length WSm of the waviness curve elements ranging from 3.0 mm to 6.0 mm.

Description

  The present invention is improved in the cleaning blade chatter, chatter, etc. when performing blade cleaning, toner slipping and filming are less likely to occur even when using a spherical toner, and the above effect can be maintained even in long-term use, The present invention relates to an electrophotographic photosensitive member that achieves both high durability and stable image quality, an image forming apparatus using the same, and a process cartridge.

An organic photosensitive layer containing an organic photoconductive material is provided on a support as an electrophotographic photosensitive member (hereinafter also simply referred to as “photosensitive member” or “image carrier”) mounted on a laser printer or a digital copying machine. An electrophotographic photosensitive member is generally used. Among them, a laminated organic electrophotographic photosensitive member in which a charge generating material and a charge transporting material are contained in separate layers is mainly used. This is due to cost, productivity, and freedom of material design.

  Since these electrophotographic photoreceptors are exposed to mechanical external force, electrical or chemical hazards in the electrophotographic image forming process, they undergo various deteriorations. In particular, the output of color images has recently increased, and electrophotographic organic electrophotographic photoreceptors that are used repeatedly over a long period of time are required to have durability against these deteriorations more than ever.

  Various attempts have been made to improve the durability of organic photoreceptors. At present, the formation of a crosslinked resin film on the surface of the photoreceptor (Patent Document 1) and the formation of a sol-gel cured film on the surface of the photoreceptor (Patent Document 2) are particularly promising. The former has the merit that even when a charge transporting component is blended, cracks and cracks hardly occur and the production yield can be reduced. Among these, radically polymerizable acrylic resins are advantageous because a tough photoconductor with good sensitivity characteristics can be easily obtained. In these two types of measures taking a cross-linked structure, a coating film is formed by a plurality of chemical bonds. Therefore, even if the coating film is stressed and a part of the chemical bond is broken, it does not immediately progress to wear.

  In addition, developing toners used for photography are advantageous in terms of ecology and high image quality on the production side, and therefore, it is becoming mainstream to use polymerized toner (spherical toner). This polymerized toner (spherical toner) is a spherical toner having no angularity, and is produced by a chemical production method such as a suspension polymerization method, an emulsion aggregation polymerization method, an ester elongation polymerization method, or a dissolution suspension method. The shape of the polymerized toner varies depending on the manufacturing method, and the polymerized toner used in the image forming apparatus is slightly distorted in shape than the true sphere. Typical characteristic values are 0.95 to 0.99 for the average circularity, and 110 to 140 for the shape factors SF-1 and SF-2. When the average circularity is 1.0 and the shape factors SF-1 and SF-2 are 100, a true sphere is represented.

  Since the polymerized toner has a uniform shape, the electric charge to be held is relatively easy to align. Moreover, it is easy to add wax (5 to 10%). Therefore, since there is almost no protrusion from an electrostatic latent image, developability is good, sharpness, resolution, and gradation are excellent, and transfer efficiency is also good. In addition, there are many advantages such as no need for oil during transfer.

  On the other hand, with the increase in the output of color images, higher image quality is required than before, but in particular, the cleaning performance of residual toner remaining on the electrophotographic photosensitive member for each image formation is required more than before. Yes. This is because the wear durability of the electrophotographic photosensitive member is realized as described above, but the durability of the cleaning performance is still unsatisfactory compared to the wear resistance. In long-term repeated image formation, small scratches and cracks may occur on the surface of the electrophotographic photosensitive member, and the blade slides on the surface of the electrophotographic photosensitive member with the tip of a hard blade for cleaning. In some cases, fine toner may slip through. In particular, when the latter occurs, black streaks appear in the image and the image quality deteriorates at a stroke. This phenomenon becomes prominent particularly when the above-described polymerized toner is used, and image degradation due to toner slipping is an urgent issue for a highly durable electrophotographic photosensitive member.

  Known cleaning members used in image forming apparatuses include a brush cleaning method using a fiber brush, a blade cleaning method using a rubber blade, and a cleaning method using a combination of both. The blade cleaning method is frequently used because of its relatively good quality and high cleaning efficiency.

  The cleaning blade is a rubber plate (blade) formed into a plate shape fixed to a support such as an aluminum plate or an iron plate. A constant load (pressing) is applied, and the edge of the blade is applied to the electrophotographic photosensitive member. It is installed so that it abuts. As means for contacting the electrophotographic photosensitive member, the blade edge makes contact with the electrophotographic photosensitive member in the counter direction (the direction in which the blade edge bites when the electrophotographic photosensitive member rotates = the reverse direction), and the tray. There is a method of contacting in the ring direction (direction in which the blade edge licks (no bite) when the electrophotographic photosensitive member rotates) = forward direction). It has become commonplace. That is, the counter abutment causes the edge of the cleaning blade to bite by the rotation of the electrophotographic photosensitive member, so that the gap between the electrophotographic photosensitive member and the blade edge is eliminated and the cleaning property is improved.

  On the other hand, as described above, as for the cleaning blade, a counter system in which the tip is positioned and brought into contact with the moving direction of the latent image carrier so as to be a counter is well known. The tip of the cleaning blade is pulled in the driving direction of the electrophotographic photosensitive member due to friction on the surface of the electrophotographic photosensitive member. Although the life of the photoconductor is improved by strengthening the surface layer of the photoconductor, the cleaning blade in contact with the photoconductor is subjected to a mechanical hazard more than the conventional photoconductor. For this reason, the cleaning blade is likely to be deteriorated, the blade is often turned over and the edge portion is chipped, and the toner is seen to slip through the turned portion and the cut portion. Toner slip may occur as an abnormal image such as streak-like stains. Further, when the contact condition becomes unstable, there is a problem that the tip of the blade is chattered and an unpleasant sound (hereinafter referred to as blade squeal) is generated.

  In order to solve these problems, many methods for improving the cleaning property have been disclosed, and in particular, many methods for roughening the surface of the photoreceptor have been disclosed. For example, by controlling the drying conditions when forming the surface layer, a method of roughening the surface of the electrophotographic photosensitive member into a rough skin shape (Patent Document 3), or by incorporating particles in the surface layer A technique (Patent Document 4) for roughening the surface of an electrophotographic photosensitive member is disclosed. In addition, a method of mechanically roughening the surface is also disclosed, and a technique for roughening the surface of the photoreceptor by polishing the surface of the surface layer using a film-like abrasive (Patent Document 5), A technique (Patent Document 6) for roughening the peripheral surface of an electrophotographic photosensitive member by blasting is disclosed. However, although these surface roughening techniques initially show good cleaning properties, there has been a problem in that the photoreceptor is worn by long-term use, and the cleaning effect due to surface roughening is reduced.

  In addition, Patent Document 7 proposes a measure for preventing noise by inserting a balancer into the electrophotographic photosensitive drum. If a balancer is included, it is not a good idea that a shaft that is advantageous for improving the accuracy of driving an electrophotographic photosensitive member cannot be used, that it is difficult to apply to a large drum diameter, and that the cost is increased.

  Patent Document 8 discloses a method of blending fluororesin fine particles in the surface layer of the electrophotographic photosensitive member. The inclusion of the fluororesin fine particles brings about a decrease in the hardness of the surface layer, which causes a new problem and is not a good idea.

  Patent Document 9 discloses a technique of forming grooves in the circumferential direction of a cross-linked resin surface layer containing a filler of a photoreceptor, but this is a great improvement in cleaning performance, but in terms of blade squealing. Not enough solution.

  Further, Patent Document 10 discloses a technique for improving the blade squealing in combination with a cleaning blade having a hard coating layer by forming a convex portion on the surface layer of the photoreceptor. In some cases, the edge was broken at the convex portion of the layer.

  As described above, the photoreceptors in these prior arts have excellent overall characteristics with respect to mechanical characteristics, electrical characteristics, toner cleaning properties, and problems related to the cleaning blade (such as creaking and squeal). I can't say that.

  The present invention has been made in view of the above-described problems in the prior art, and the photoreceptor itself has high wear resistance and good electrical characteristics, while suppressing deterioration of the cleaning blade, and good cleaning properties and cleaning. An object of the present invention is to provide an electrophotographic photosensitive member capable of preventing the frictional noise between the blade and the electrophotographic photosensitive member for a long period of time. Another object of the present invention is to provide an image forming apparatus using the high-performance electrophotographic photosensitive member and a process cartridge for the image forming apparatus.

The present invention provided to solve the above problems is as follows. In addition, the site | part and code | symbol etc. which respond | correspond in the form for implementing this invention in a parenthesis are shown.
[1] Electrons having at least a photosensitive layer (charge generation layer (25), charge transport layer (26)) and a surface layer (surface layer (28)) on a conductive support (conductive support (21)). In the photographic photosensitive member, the surface shape in the axial direction of the electrophotographic photosensitive member is measured by a contour curve method, the roughness component is cut off at a cutoff value of 2.5 mm of the λc contour curve filter, and the cut of the λf contour curve filter is performed. The arithmetic mean waviness Wa in the waviness curve obtained by blocking the wavelength component longer than the waviness at the off value of 8.0 mm is 0.08 μm to 0.20 μm, and the average length WSm of the waviness curve element is 3.0 mm to 6 Electrophotographic photosensitive member (electrophotographic photosensitive member (11), FIGS. 1 and 2), characterized in that the thickness is 0.0 mm.
[2] The electrophotographic photosensitive member according to [1], wherein the surface layer contains filler fine particles.
[3] The electrophotographic photosensitive member according to [2], wherein the filler fine particles are inorganic fillers.
[4] The electrophotographic photosensitive member according to [2] or [3], wherein the filler fine particles are made of alumina.
[5] The surface layer is made of a crosslinkable resin, and the crosslinkable resin has structural units derived from a crosslinkable charge transport material having a triarylamine structure. The electrophotographic photosensitive member according to any one of the above.
[6] The electrophotographic photosensitive member according to any one of [1] to [5], wherein the surface layer is coated by a spray coating method.
[7] The surface layer is spray-coated through a mask (mask (M)) having openings (openings (Mw)) arranged at a constant pitch in the axial direction of the electrophotographic photosensitive member. The electrophotographic photosensitive member according to [6] above (FIG. 4).
[8] The electrophotographic photosensitive member (electrophotographic photosensitive member (11)) according to any one of [1] to [7], a charging unit (charging unit (12)), and an exposure unit (exposure unit (13). )), Developing means (developing means (14)), transfer means (transfer means (16)), and cleaning means (cleaning means (17)) having a cleaning blade for rubbing the electrophotographic photosensitive member, An image forming apparatus (FIGS. 5 and 7 to 9).
[9] The image forming apparatus according to [8], wherein the developing unit uses spherical toner (toner (15)) having an average circularity of 0.95 or more and 0.99 or less.
[10] The development unit according to [8] or [9], wherein the development unit has a development station of at least two colors and is a tandem type and further develops using polymerized toner. Image forming apparatus (FIGS. 7 to 9).
[11] At least the electrophotographic photosensitive member (electrophotographic photosensitive member (11)) according to any one of [1] to [7], a developing unit (developing unit (14)), and a cleaning unit (cleaning unit ( 17)) a process cartridge detachably attached to the main body of the image forming apparatus, wherein the cleaning means comprises a cleaning blade for rubbing the electrophotographic photosensitive member (FIG. 6).

  According to the present invention, the surface shape in the axial direction of the electrophotographic photosensitive member is measured by the contour curve method, the roughness component is cut off at the cutoff value of 2.5 mm of the λc contour curve filter, and the cut of the λf contour curve filter is performed. The arithmetic mean waviness Wa in the waviness curve obtained by blocking the wavelength component longer than the waviness at the off value of 8.0 mm is 0.08 μm to 0.20 μm, and the average length WSm of the waviness curve element is 3.0 mm to 6 By being 0.0 mm, the photoconductor is excellent in abrasion resistance and electrical characteristics, and the deterioration of the cleaning blade is reduced, and the good cleaning performance and the rubbing noise between the electrophotographic photoconductor and the cleaning blade are prevented. An electrophotographic photosensitive member that can be sustained for a long time can be provided. In addition, according to the present invention, it is possible to provide an image forming apparatus and a process cartridge for the image forming apparatus that have realized excellent cleaning properties over a long period of time.

It is sectional drawing which shows the layer structure of the electrophotographic photoreceptor which concerns on this invention. It is sectional drawing which shows another layer structure of the electrophotographic photoreceptor which concerns on this invention. It is the schematic which shows a mode that the surface layer in the electrophotographic photoreceptor of this invention is formed by spray coating. It is a front view which shows the structure of the mask used in the case of surface layer formation. 1 is a schematic cross-sectional view illustrating a configuration example (1) of an image forming apparatus according to the present invention. FIG. 3 is a schematic cross-sectional view illustrating a configuration example of a process cartridge according to the present invention. It is a schematic cross section showing a configuration example (2) of the image forming apparatus according to the present invention. It is a schematic cross-sectional view showing a configuration example (3) of the image forming apparatus according to the present invention. It is a schematic cross section which shows the structural example (4) of the image forming apparatus which concerns on this invention. 2 is a schematic cross-sectional view showing a means for supplying a solid lubricant to a photoreceptor. FIG. It is a block diagram of a surface roughness / contour shape measurement system. It is an example figure of the waviness curve of the electrophotographic photosensitive member of the present invention. It is an example figure of the waviness curve of the electrophotographic photosensitive member outside the scope of the present invention. FIG. 3 is an example diagram showing a layout around a photoconductor related to slip-through measurement. It is a frequency characteristic of the driving operation sound of the electrophotographic photosensitive member in a blank state where the photosensitive unit is not set. 3 is a frequency characteristic of driving operation sound of an electrophotographic photosensitive member when an electrophotographic photosensitive member outside the range of the present invention is mounted. 3 is a frequency characteristic of driving operation sound of the electrophotographic photosensitive member when the electrophotographic photosensitive member of the present invention is mounted.

  The configurations of the electrophotographic photosensitive member, the image forming apparatus, and the process cartridge according to the present invention will be described below.

[Electrophotographic photoreceptor]
The electrophotographic photosensitive member according to the present invention has at least a photosensitive layer and a surface layer on a conductive support (hereinafter also simply referred to as a support), and the contour of the surface shape in the axial direction of the electrophotographic photosensitive member. Waviness curve obtained by measuring with a curve method, blocking the roughness component with the cutoff value of 2.5 mm of the λc contour curve filter, and blocking the wavelength component longer than the waviness with the cutoff value of 8.0 mm of the λf contour curve filter. The arithmetic average waviness Wa in is 0.08 μm to 0.20 μm, and the average length WSm of the waviness curve elements is 3.0 mm to 6.0 mm.
Hereinafter, the electrophotographic photoreceptor of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a cross-sectional view schematically showing an example of the layer structure of the electrophotographic photosensitive member of the present invention, which comprises a charge generation layer (25) and a charge transport layer (26) on a conductive support (21). A photosensitive layer and a surface layer (28) are provided.
FIG. 2 is a cross-sectional view schematically showing an example of an electrophotographic photosensitive member having still another layer structure of the present invention, between the conductive support (21) and the charge generation layer (25). An undercoat layer (24) is provided, and a charge transport layer (26) and a surface layer (28) are provided on the charge generation layer (25).

<Support>
The support (21) is not particularly limited as long as it has a volume resistance of 1.0 × 10 ¹⁰ Ω · cm or less, and can be appropriately selected according to the purpose. Metals such as aluminum, nickel, chromium, nichrome, copper, gold, silver, platinum, and metal oxides such as tin oxide and indium oxide coated with film or cylindrical plastic or paper by vapor deposition or sputtering, Alternatively, a plate made of aluminum, aluminum alloy, nickel, stainless steel or the like, and a tube subjected to surface treatment such as cutting, super-finishing, polishing, etc. after forming them into a drum shape by a method such as extrusion or drawing can be used. .

The drum-shaped support (21) preferably has a diameter of 20 mm to 150 mm, more preferably 24 mm to 100 mm, and still more preferably 28 mm to 70 mm. When the diameter of the drum-shaped support is less than 20 mm, it may be physically difficult to arrange the charging, exposure, development, transfer, and cleaning steps around the drum, and when the diameter exceeds 150 mm. The image forming apparatus may become large. In particular, when the image forming apparatus is a tandem type, since it is necessary to mount a plurality of photoconductors, the diameter is preferably 70 mm or less, and more preferably 60 mm or less.
An endless nickel belt or an endless stainless steel belt as disclosed in JP-A-52-36016 can also be used as a support.

<Photosensitive layer>
The photosensitive layer is not particularly limited and may be appropriately selected depending on the purpose. For example, a single-layer type photosensitive layer in which a charge generation material and a charge transport material are mixed, as shown in FIGS. Examples thereof include a laminated photosensitive layer in which a generation layer (25) and a charge transport layer (26) are laminated.

  Examples of the multilayer photosensitive layer include a multilayer photosensitive layer having a charge generation layer and a charge transport layer in this order from the support side, and a multilayer photosensitive layer having a charge transport layer and a charge generation layer in this order from the support side. Layer. Among these, a laminated photosensitive layer having a charge generation layer and a charge transport layer in this order from the support side is preferable from the viewpoint of durability.

-Charge generation layer-
The charge generation layer contains at least a charge generation material, and further contains other components such as a resin as necessary.

-Charge generation material-
The charge generation material is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include inorganic charge generation materials and organic charge generation materials.

  The inorganic charge generating material is not particularly limited and may be appropriately selected depending on the intended purpose.For example, crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, selenium-arsenic compound, Examples include amorphous silicon. Examples of the amorphous silicon include those obtained by terminating dangling bonds with hydrogen atoms or halogen atoms, and those doped with boron atoms or phosphorus atoms.

  The organic charge generating material is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include monoazo pigments, disazo pigments, asymmetrical disazo pigments, trisazo pigments, azo pigments having a carbazole skeleton, and distyrylbenzene. An azo pigment having a skeleton, an azo pigment having a triphenylamine skeleton, an azo pigment having a diphenylamine skeleton, an azo pigment having a dibenzothiophene skeleton, an azo pigment having a fluorenone skeleton, an azo pigment having an oxadiazole skeleton, and a bis-stilbene skeleton Azo pigments, azo pigments having a distyryl oxadiazole skeleton, azo pigments such as an azo pigment having a distyrylcarbazole skeleton; azulenium salt pigments, squalic acid methine pigments, perylene pigments, anthraquinone or polycyclic quinone Pigment, key Ninine pigments, diphenylmethane and triphenylmethane pigments, benzoquinone and naphthoquinone pigments, cyanine and azomethine pigments, indigoid pigments, bisbenzimidazole pigments, phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, etc. . These may be used individually by 1 type and may use 2 or more types together.

--Resin--
The resin used as necessary for the charge generation layer is not particularly limited and can be appropriately selected according to the purpose. For example, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, Polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, poly-N-vinyl carbazole, polyacrylamide, polyvinyl benzal, polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyvinyl pyridine, cellulose Resin, casein, polyvinyl alcohol, polyvinyl pyrrolidone, etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.

  There is no restriction | limiting in particular as content of the said resin, Although it can select suitably according to the objective, 500 mass parts or less are preferable with respect to 100 mass parts of said charge generation materials, and 10 mass parts-300 mass parts are. More preferred.

There is no restriction | limiting in particular as a method of forming the said charge generation layer, According to the objective, it can select suitably, For example, a vacuum thin film preparation method, a casting method, etc. are mentioned.
Examples of the vacuum thin film production method include a vacuum deposition method, a glow discharge decomposition method, an ion plating method, a sputtering method, a reactive sputtering method, and a CVD (chemical vapor deposition) method.
Examples of the casting method include a dip coating method, a spray coating method, and a bead coating method.

  In the casting method, a coating solution is usually used. The coating liquid is not particularly limited and may be appropriately selected depending on the purpose. For example, the charge generating substance may be used together with the resin as necessary, and may be a known ball mill, attritor, sand mill, ultrasonic wave, or the like. And a coating solution dispersed in a solvent using the above dispersion method. The resin may be added before or after the charge generating material is dispersed. The coating liquid contains a charge generation material, a solvent and a resin as main components, but may contain additives such as a sensitizer, a dispersant, a surfactant, and silicone oil. In some cases, it is also possible to add a charge transport material described later to the charge generation layer.

  The solvent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, isopropanol, acetone, methyl ethyl ketone, dioxolane, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane And generally used organic solvents such as monochlorobenzene, cyclohexane, toluene, xylene, ligroin and the like. Among these, it is preferable to use a ketone solvent, an ester solvent, or an ether solvent. These may be used individually by 1 type and may use 2 or more types together.

  The charge generation layer is formed by coating on the support or undercoat layer using the coating solution and drying. As the coating method, known methods such as dip coating, spray coating, bead coating, nozzle coating, spinner coating, ring coating, and the like can be used. You may heat-dry using oven etc. after coating. There is no restriction | limiting in particular as drying temperature, Although it can select suitably according to the objective, 50 to 160 degreeC is preferable and 80 to 140 degreeC is more preferable.

  There is no restriction | limiting in particular as thickness of the said charge generation layer, Although it can select suitably according to the objective, 0.01 micrometer-5 micrometers are preferable, and 0.05 micrometer-2 micrometers are more preferable. Increasing the thickness of the charge generation layer is advantageous for reducing the residual potential and increasing the sensitivity, but on the other hand, it may cause a decrease in chargeability such as charge charge retention and space charge formation. The preferable range is advantageous in that these balances can be achieved, and the effect is remarkable when the preferable range is satisfied.

-Other ingredients-
Examples of the other components include an antioxidant, a plasticizer, a lubricant, an ultraviolet absorber, and a leveling agent. These may be used individually by 1 type and may use 2 or more types together.

  There is no restriction | limiting in particular as content of the said other component, Although it can select suitably according to the objective, 0.1 mass part-20 mass parts are preferable with respect to 100 mass parts of said charge generation materials, 0.1 mass part-10 mass parts are more preferable. In the case of a leveling agent, 0.001 to 0.1 parts by mass is preferable with respect to 100 parts by mass of the charge generation material. When the content is less than the lower limit, sensitivity deterioration may occur.

-Charge transport layer-
The charge transport layer contains at least a charge transport material, and further contains other components such as a resin as necessary.

-Charge transport material-
The charge transport material is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include an electron transport material and a hole transport material.

  Examples of the electron transporting material include electron accepting materials such as asymmetric diphenoquinone derivatives, fluorene derivatives and naphthalimide derivatives, polymers having a carbazole ring such as poly-N-vinylcarbazole, and Japanese Patent Application Laid-Open No. 57-78402. A polymer having a hydrazone structure, a polysilylene polymer exemplified in JP-A No. 63-285552, and general formulas (1) to (6) in JP-A No. 2001-330973. And aromatic polycarbonate. These may be used individually by 1 type and may use 2 or more types together.

  Among the electron transport materials, the polymer-type electron transport material is less likely to ooze into the cross-linked resin layer of the components constituting the charge transport layer when the cross-linked resin layer is laminated on the charge transport layer. It is a material suitable for preventing poor curing of the layer. Moreover, since it is excellent also in heat resistance, it is advantageous at the point that there is little deterioration by the curing heat at the time of forming a crosslinked resin layer.

  Examples of the hole transport material include oxazole derivatives, oxadiazole derivatives, imidazole derivatives, triphenylamine derivatives, butadiene derivatives, 9- (p-diethylaminostyrylanthracene), 1,1-bis- (4-dibenzyl). Aminophenyl) propane, styrylanthracene, styrylpyrazoline, phenylhydrazones, α-phenylstilbene derivatives, thiazole derivatives, triazole derivatives, phenazine derivatives, acridine derivatives, benzofuran derivatives, benzimidazole derivatives, thiophene derivatives, and the like. These may be used individually by 1 type and may use 2 or more types together.

--Resin--
There is no restriction | limiting in particular as resin used as needed for the said charge transport layer, According to the objective, it can select suitably, For example, polycarbonate resin, a styrene resin, an acrylic resin, a styrene-acrylic resin, ethylene-acetic acid Vinyl resin, polypropylene resin, vinyl chloride resin, chlorinated polyether, vinyl chloride-vinyl acetate resin, polyester resin, furan resin, nitrile resin, alkyd resin, polyacetal resin, polymethylpentene resin, polyamide resin, polyurethane resin, epoxy resin , Polyarylate resin, diarylate resin, polysulfone resin, polyethersulfone resin, polyallylsulfone resin, silicone resin, ketone resin, polyvinyl butyral resin, polyether resin, phenol resin, EVA (ethylene / vinyl acetate) Le copolymer) resins, ACS (acrylonitrile-chlorinated polyethylene-styrene) resin, ABS (acrylonitrile butadiene styrene) resin, a resin such as a photocurable resin such as epoxy acrylate. Among these, a styrene resin, a polyester resin, a polyarylate resin, and a polycarbonate resin are preferable in terms of good charge transfer characteristics. These may be used individually by 1 type and may use 2 or more types together. In addition, a mixture of resins having different molecular weights is preferable in terms of improving hardness and wear resistance. In addition to the mechanical, chemical and electrical stability, adhesion, etc., compatibility with the charge transport material is important.

  The method for forming the charge transport layer is not particularly limited and may be appropriately selected depending on the intended purpose.In normal cases, a coating liquid in which a charge transport material and an additive are dispersed or dissolved in a solvent together with a resin is used. A method of coating on the charge generation layer and drying is preferable.

  There is no restriction | limiting in particular as said solvent, According to the objective, it can select suitably, For example, alcohols, such as methanol, ethanol, n-propanol, i-propanol, a butanol; Pentane, hexane, heptane, octane, cyclohexane Saturated hydrocarbons such as cycloheptane; aromatic hydrocarbons such as toluene and xylene; chlorinated hydrocarbons such as dichloromethane, dichloroethane, chloroform and chlorobenzene; dimethyl ether, diethyl ether, tetrahydrofuran (THF), methoxyethanol, dimethoxyethane , Ethers such as dioxane, dioxolane, anisole; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone; ethyl formate, propyl formate, methyl acetate, ethyl acetate Propyl acetate, butyl acetate, esters of methyl propionate; N, N-dimethylformamide, and dimethyl sulfoxide. These may be used individually by 1 type and may use 2 or more types together. Among these, ketone solvents, ester solvents, ether solvents, and halogenated hydrocarbon solvents are particularly preferable.

  The thickness of the charge transport layer is not particularly limited and may be appropriately selected according to the purpose. However, in order to maintain a practically effective surface potential, 10 μm to 40 μm is preferable, and 15 μm to 30 μm is preferable. More preferred.

-Other ingredients-
Examples of the other components include an antioxidant, a plasticizer, a lubricant, an ultraviolet absorber, and a leveling agent. These may be used individually by 1 type and may use 2 or more types together.

  There is no restriction | limiting in particular as content of the said other component, Although it can select suitably according to the objective, 0.1 mass part-20 mass parts are preferable with respect to 100 mass parts of said charge transport materials, 0.1 mass part-10 mass parts are more preferable. In the case of a leveling agent, 0.001 mass part-0.1 mass part is preferable with respect to 100 mass parts of said charge transport materials. When the content is less than the lower limit, sensitivity deterioration may occur.

<Surface layer>
The said surface layer consists of resin, and contains another component as needed.

-Resin-
As the resin used for the surface layer, those listed in the item of the charge transport layer may be used, or a crosslinkable resin may be used. By using a crosslinkable resin for the surface layer of the photoreceptor and further containing a filler (described later), the surface layer can be very strong and have high durability and form a fine uneven shape by the filler, The cleaning property can be improved. Further, it is possible to prevent the photoreceptor from being worn and scratched and to maintain a wavy shape (described later) for a long period of time.

--- Crosslinkable resin-
The cross-linked resin is not particularly limited as long as it has a cross-linked structure, and can be appropriately selected according to the purpose. The structural unit constituting the cross-linked resin is not particularly limited and may be appropriately selected depending on the intended purpose. For example, a chain polymerization compound having an acryloyloxy group or a styryl group, a hydroxyl group, an alkoxysilyl group, an isocyanate Examples thereof include structural units derived from a sequential polymerization system compound having a group.

The chain polymerization compound having an acryloyloxy group or a styryl group is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include trimethylolpropane triacrylate, caprolactone-modified dipentaerythritol hexaacrylate, Examples include pentaerythritol hexaacrylate and methacryloyl-modified silicone oil.
Among these, a structural unit derived from trimethylolpropane triacrylate is preferable from the viewpoint of excellent wear resistance and elimination of image flow.

  The content of the structural unit derived from the trimethylolpropane triacrylate in the cross-linked resin is not particularly limited and may be appropriately selected depending on the purpose, but from the viewpoint of excellent wear resistance, 10 mass parts-70 mass parts are preferable with respect to 100 mass parts of solid content, and 30 mass parts-60 mass parts are more preferable.

  The cross-linked resin preferably contains the charge transport material from the viewpoint of electrophotographic characteristics, versatility, material design, and production stability, and has a structural unit derived from the cross-linkable charge transport material. More preferably.

  The crosslinkable charge transport material is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a structure derived from a charge transport material and a compound having a (meth) acryloyloxy group, and a charge transport material. Compound derived from structure and styryl group, structure derived from charge transport material and compound having hydroxyl group, structure derived from charge transport material and compound having alkoxysilyl group, structure derived from charge transport material and having isocyanate group Compound etc. are mentioned.

  There is no restriction | limiting in particular as a structure derived from the said charge transport material, Although it can select suitably according to the objective, A triarylamine structure is preferable at the point of high-sensitivity.

  As a compound having a structure derived from the charge transport material and a (meth) acryloyloxy group, a crosslinkable charge transport material having a triarylamine structure represented by the following general formula (1) is highly sensitive and It is preferable in terms of wear resistance.

  Moreover, as a compound represented by the said General formula (1), the following compounds (No.1-No.26) are mentioned, for example.

  The surface layer may contain an antioxidant, a plasticizer, a lubricant, an ultraviolet absorber, a leveling agent, a foaming agent, organic fine particles and the like as other components. There is no restriction | limiting in particular as these content, Although it can select suitably according to the objective, 0.1 mass part-20 mass parts are preferable with respect to 100 mass parts of solid content of the said surface layer, 0 More preferably, 1 part by mass to 10 parts by mass. In addition, as content of a leveling agent, 0.1 mass part-5 mass parts are preferable with respect to 100 mass parts of solid content of the said surface layer.

  The method for forming the surface layer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a method of applying a paint (surface layer paint) containing a material for forming the surface layer. It is done.

  The surface layer coating material may contain a photopolymerization initiator such as 1-hydroxycyclohexyl phenyl ketone in order to promote curing or stabilize the coating.

The surface layer coating material may contain a solvent.
There is no restriction | limiting in particular as said solvent, Although it can select suitably according to the objective, Methyl ethyl ketone, tetrahydrofuran, cyclohexanone, 1-methoxy-2-propanol etc. are preferable from a viewpoint of environmental impact.

  The coating method for the surface layer coating is not particularly limited as long as the surface shape (waviness shape) described later can be formed, and can be appropriately selected according to the purpose. For example, dipping, spray coating, ring coating Method, roll coating method, gravure coating method, nozzle coating method, screen printing method and the like. Among these, the spray coating method and the ring coating method are preferable.

  The surface layer can be applied at a time to form a surface layer. However, the surface layer is applied two or more times to form a multilayered surface layer from the viewpoint of the uniformity of the filler in the layer. preferable. As a result, a further effect can be obtained with respect to reduction of residual potential, improvement of resolution, and improvement of wear resistance.

When the crosslinkable resin is used, in order to crosslink the crosslinkable material, a UV irradiation light source such as a high pressure mercury lamp or a metal halide lamp having an emission wavelength mainly in the ultraviolet region may be used.
As the illuminance of the UV radiation source is not particularly limited and may be appropriately selected depending on the intended purpose, 50 mW / cm ² or more 1000 mW / cm ² or less. When the illuminance is less than 50 mW / cm ² , it may take time for the crosslinking reaction, and when it exceeds 1000 mW / cm ² , the progress of the crosslinking reaction may be uneven, In some cases, wrinkles may occur, or many unreacted residues and reaction termination ends may occur. In addition, the internal stress increases due to a rapid crosslinking reaction, and the surface layer may be cracked or peeled off.

  There is no restriction | limiting in particular as thickness of the said surface layer, Although it can select suitably according to the objective, 3 micrometers-15 micrometers are preferable. When the thickness of the surface layer is remarkably increased, it is recognized that the image quality tends to be slightly deteriorated.

-Surface shape-
The electrophotographic photosensitive member according to the present invention has at least a photosensitive layer and a surface layer on a conductive support, and has a predetermined undulation shape on the surface thereof.
Here, the predetermined waviness shape means that the surface in the axial direction of the electrophotographic photosensitive member is measured by a contour curve method, the roughness component is cut off with a cutoff value of 2.5 mm of the λc contour curve filter, and the λf contour curve The arithmetic mean waviness Wa in the waviness curve obtained by blocking the wavelength component longer than the waviness with the filter cutoff value of 8.0 mm is 0.08 μm to 0.20 μm, and the average length WSm of the waviness curve element is 3. The surface shape is 0 mm to 6.0 mm. Further, there is no such undulation shape in the circumferential direction of the electrophotographic photosensitive member.

  As described above, the surface of the electrophotographic photosensitive member in the axial direction has a large wavy shape, thereby greatly improving the cleaning performance, further suppressing the squealing and creaking of the cleaning blade, and providing good cleaning performance for a long time. It can be sustained. Further, the wavy shape can reduce the contact area between the electrophotographic photosensitive member and the cleaning blade, thereby suppressing the deterioration of the cleaning blade.

Details are as follows.
When the electrophotographic photosensitive member is driven in the image forming apparatus, the cleaning blade in contact with the electrophotographic photosensitive member is pulled to the driving direction of the electrophotographic photosensitive member to some extent, and this causes a stick-slip motion. This stick-slip motion moves in the direction of the restoring state at once when the restoring force due to the elasticity of the cleaning blade becomes larger than the maximum static frictional force on the electrophotographic photosensitive member, and then the cleaning blade moves when the restoring force is weakened. Is interpreted as a movement that is dragged again in the driving direction of the photosensitive member.

In the present invention, by giving the surface shape to the surface of the electrophotographic photosensitive member, the vibration of the cleaning blade is added according to the period of the convex shape of the surface of the photosensitive member, and the blade squeal is alleviated. It has been found that it is possible to ensure the mekure and cleaning properties at the same time.
Specifically, the waviness shape in the axial direction of the surface layer is such that the arithmetic average waviness Wa in the waviness curve is 0.08 μm to 0.20 μm, and the average length Wsm of the waviness curve elements is 3.0 mm to 6.0 mm. At this time, the cleaning blade is effective in suppressing the noise, the creaking and the toner slipping. The waviness shape of the surface layer is more preferably an arithmetic average waviness Wa of 0.10 μm to 0.20 μm and an average length WSm of waviness curve elements of 3.5 mm to 5.5 mm.

  When the arithmetic mean waviness Wa is larger than 0.2 μm, the film thickness difference between the surface layers becomes large, and thus density unevenness and dot dust may occur in the image forming process. Further, when the arithmetic average waviness Wa is less than 0.08 μm, the surface layer waviness is small, so that the blade vibration is small, and the cleaning blade squealing suppressing effect cannot be obtained.

  When the average length WSm of the waviness curve element is larger than 6.0 mm, the waviness has a large amplitude, so that the effect of reducing the noise of the cleaning blade cannot be obtained sufficiently. When the average length WSm of the waviness curve element is smaller than 3.0 mm, the blade does not vibrate and the cleaning property is lowered, and the blade is likely to be turned up.

--Measurement method of surface shape--
The arithmetic average waviness Wa and the average length WSm of the waviness curve element described above are parameters obtained from a waviness curve obtained by removing a short wavelength roughness component of 2.5 mm or less and a wavelength of 8.0 mm or more. The arithmetic mean waviness Wa and the mean length WSm of the waviness curve element are compliant with JIS B 0601 (2001 standard), and the roughness component is cut off with a cut-off value of 2.5 mm of the λc contour curve filter. It is calculated from an undulation curve in which a wavelength component longer than the undulation is cut off with a cutoff value of 8.0 mm of the λf contour curve filter.

  In the present invention, measurement is performed at a measurement length of 50.0 mm and a measurement speed of 0.6 mm / s using a surface roughness meter Surfcom 1400D manufactured by Tokyo Seimitsu. Any measuring device may be used as long as it is possible.

  Moreover, although there is no restriction | limiting about a measurement position or the number of measurement, in order to reduce a measurement error, it is preferable to measure several points. For example, in the case of a cylindrical electrophotographic photosensitive member, a measurement error is obtained by measuring a total of 12 points, that is, three points at the upper end, the center, and the lower end in the longitudinal direction, and four points every 90 ° in the circumferential direction. Can be obtained.

-Surface shape formation method-
The method for controlling the waviness shape of the surface layer of the electrophotographic photosensitive member includes a method for controlling waviness during coating in the coating process, a method for forming waviness by prescribing the coating solution, and coating on a substrate having waviness. There is a method of forming a film and a method of forming a wave mechanically after film forming, and any method is acceptable. However, since wave control can be controlled relatively easily and at low cost, the wave is generated during coating in the coating process. A method for controlling the waviness and a method for controlling the swell according to the formulation of the coating liquid are preferred.

  When controlling the undulation during coating, it is preferable to control the undulation using the spray coating method as the coating method, and the atomizing air pressure and discharge rate during spray coating, the distance between the spray gun and the substrate, coating The swell can be controlled by spray application conditions such as the number of times. In addition, there is a method of installing a mask corresponding to a desired pattern in front of the surface to be coated.

  It is also possible to form a swell by spraying a solvent or air after spray coating. When the swell is controlled by the formulation of the coating liquid, the swell can be controlled by the type and amount of the leveling agent and the solvent in the coating liquid and the solid content concentration of the coating liquid. It is also possible to control the swell more effectively by combining the formulation of these coating solutions and the spray coating method.

  Hereinafter, as an example of a method for controlling the undulation of the electrophotographic photosensitive member surface, a method for controlling the undulation in the case of forming a surface layer by a spray coating method will be described. However, the undulation control method of the present invention is limited to this. It is not a thing.

  When the surface layer is formed by spray coating method and the undulation is controlled, any spray gun can be used at the time of spray coating, but the discharge amount of the coating liquid, the atomizing air flow rate, the atomizing air pressure, etc. can be controlled. Those are preferred. Examples of the spray gun include air spray, airless spray, electrostatic spray and the like. The spray may be vertical or horizontal. In the present invention, coating is performed using an air spray A100 manufactured by Meiji Machinery Co., Ltd.

  In FIG. 3, the outline at the time of forming the surface layer in the electrophotographic photoreceptor of this invention by spray coating is shown. Reference numeral (A) indicates a spray gun, and reference numeral (B) indicates a substrate to be coated. In FIG. 3, a substrate (B) is a photoreceptor production stage product in which a photosensitive layer is coated on a support, and a cylindrical support is used as the support. The substrate (B) is rotated in the direction of the arrow by the driving means, and the spray gun (A) is applied to the substrate while atomizing the surface layer coating liquid. At this time, the spray gun (A) moves slowly in the direction of the arrow from the left end of the substrate (B), and coats the entire surface of the substrate (B) with the surface layer coating solution. The number of coating times of the surface layer coating solution is arbitrary.

  The moving speed of the spray gun (A) and the number of rotations of the substrate (B) are arbitrary, but the moving speed of the spray gun (A) is 10 mm / s or less and the substrate (B) from the viewpoint of suppressing the occurrence of uneven coating. Is preferably 60 rpm or more.

  Further, the distance between the spray gun (A) and the substrate (B) is preferably 20 mm to 100 mm, and more preferably 30 mm to 70 mm. If it is less than 20 mm, the distance between the spray gun (A) and the substrate (B) is too short, and coating unevenness is likely to occur. If it exceeds 100 mm, the distance between the spray gun (A) and the substrate (B) becomes long. The solvent in the atomized droplets discharged from the spray gun (A) is likely to evaporate, and the droplets become small, so that it is difficult to form undulations.

  The discharge amount of the coating liquid is preferably 0.02 ml / s or more. If it is less than 0.02 ml / s, since the discharge amount is small, the droplets become fine and undulation is difficult to be formed. The discharge amount can be controlled by the nozzle opening of the spray gun (A), the push-out amount of the syringe pump, and the like.

  Moreover, it is also possible to form a wave | undulation by spraying a solvent and air with the coating liquid in the wet state immediately after a coating film. When the solvent is sprayed, the type of the solvent is arbitrary, but a solvent having a low boiling point is preferable so as not to remain on the coating film surface after spraying.

Next, a case where a mask is placed between the substrate (B) and the spray gun (A) in FIG. 3 to control the undulation of the electrophotographic photosensitive member surface will be described.
By installing a mask having a desired opening pattern between the base body (B) and the spray gun (A), the coating liquid is applied to the base body (B) side, similar to the mask pattern. At this time, how much the waviness on the surface of the electrophotographic photoreceptor is similar to the opening pattern of the mask is determined by the distance between the substrate (B) and the mask, the touch drying time immediately after coating, the viscosity of the coating solution, and the like. .

As shown in FIG. 4, the mask (M) used here has openings (Mw) arranged at a constant pitch corresponding to the axial direction (left-right direction in the figure) of the electrophotographic photosensitive member. is there. Each dimension (horizontal dimension A, vertical dimension B, opening (Mw) width C, length (E), opening interval D) in the mask (M) is the distance between the substrate and the mask, and the touch is dried immediately after coating. From the relationship with the time, the viscosity of the coating solution, etc., it is determined so as to have the waviness shape.
The material of the mask is not particularly limited as long as it is unnecessary for the solvent. For example, stainless steel may be used.

  Table 1 shows an example of dimensions of the mask (M). In Examples and Comparative Examples described later, a mask (M) based on this dimension table is used, and the material at that time is stainless steel.

-Filler addition-
In the surface layer, the surface waviness and fine irregularities are given, so that in the cleaning process during the image forming process, the cleaning blade in contact with the photoconductor causes slight vibration on the photoconductor surface, and the residual toner on the photoconductor Wiping can be improved. In the present invention, the addition of a filler to the surface layer gives both fine irregularities and a large waviness shape, greatly improving the cleaning performance, and further suppressing the squealing and creaking of the cleaning blade, and good cleaning performance. Can be sustained for a long time.

  Further, since the filler forms fine irregularities on the surface layer, the fine vibration of the cleaning blade is made more effective. When the filler is not used, the photosensitive member is scraped and the waviness shape disappears due to long-term use, and thus the cleaning property may gradually deteriorate. Therefore, the inclusion of the filler makes it possible to maintain the waviness shape for a long period of time and to provide a good cleaning property for a long period of time.

  The particle diameter of the filler fine particles is preferably 0.1 μm to 1.0 μm, more preferably 0.1 μm to 0.5 μm. When the thickness is less than 0.1 μm, the improvement in wear resistance by the filler is small, and a great improvement in maintaining the waviness shape cannot be obtained. When the filler particle size is larger than 1.0 μm, the local resistance to the cleaning blade increases, and the cleaning blade may be damaged.

The filler can be an inorganic filler or an organic filler.
Examples of the organic filler include fluororesin powders such as polytetrafluoroethylene; silicone resin powders, a-carbon powders, and the like.
Examples of the inorganic filler include metal powders such as copper, tin, aluminum, and indium; alumina such as silica, tin oxide, zinc oxide, titanium oxide, and α-alumina, zirconium oxide, indium oxide, antimony oxide, bismuth oxide, Examples thereof include metal oxides such as calcium oxide, antimony-doped tin oxide and tin-doped indium oxide; metal fluorides such as tin fluoride, calcium fluoride and aluminum fluoride; potassium titanate, boron nitride and the like. Among these, it is preferable to use an inorganic filler from the viewpoint of the hardness of the filler from the viewpoint of improving the wear resistance.

  The content of the filler is not particularly limited and may be appropriately selected depending on the purpose.From the viewpoint of reducing damage to other members such as a cleaning blade that rubs against the electrophotographic photosensitive member, 1 mass% or more and 50 mass% or less are preferable with respect to solid content of a surface layer, and 5 mass% or more and 35 mass% or less are more preferable.

  Furthermore, these fillers can be surface-treated with at least one kind of surface treatment agent, and it is preferable from the viewpoint of filler dispersibility. Decreasing the dispersibility of the filler not only increases the residual potential, but also decreases the transparency of the coating, causes defects in the coating, and decreases the wear resistance. This is because it can develop into a big problem.

As the surface treatment agent, a conventionally used surface treatment agent can be used, but a surface treatment agent capable of maintaining the insulating properties of the filler is preferable.
The surface treatment amount varies depending on the average primary particle size of the filler used, but is preferably 3 to 30% by weight and more preferably 5 to 20% by weight with respect to the filler weight. If the surface treatment amount is less than this, the filler dispersion effect cannot be obtained, and if it is too much, the residual potential is significantly increased. These filler materials may be used alone or in combination of two or more.

<Other configurations>
As said other structure, an undercoat layer (24) etc. are mentioned, for example.
-Undercoat layer-
The undercoat layer may be provided between the support and the photosensitive layer as necessary. The undercoat layer is provided for the purpose of improving adhesiveness, preventing moire, improving the coatability of the upper layer, and reducing residual potential.
Examples of the material for the undercoat layer include those containing a resin and fine powder, and further containing other components as necessary.

--Resin--
Examples of the resin include water-soluble resins such as polyvinyl alcohol resin, casein, and sodium polyacrylate; alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon; polyurethane resins, melamine resins, alkyd-melamine resins, and epoxy resins. And a curable resin that forms a three-dimensional structure.

--Fine powder--
Examples of the fine powder include metal oxides such as titanium oxide, silica, alumina, zirconium oxide, tin oxide, and indium oxide, metal sulfides, and metal nitrides.

-Other ingredients-
There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, For example, a silane coupling agent, a titanium coupling agent, a chromium coupling agent etc. are mentioned.

As the undercoat layer, an anodized layer of Al ₂ O ₃ , an organic material such as polyparaxylylene (parylene), or an inorganic material such as SiO ₂ , SnO ₂ , TiO ₂ , ITO, or CeO ₂ is used. The thing provided by the vacuum thin film preparation method etc. are mentioned.

  There is no restriction | limiting in particular as thickness of the said undercoat layer, Although it can select suitably according to the objective, 0.1 micrometer-50 micrometers are preferable, and 0.5 micrometer-20 micrometers are more preferable.

[Image forming apparatus and process cartridge]
The image forming apparatus according to the present invention includes the electrophotographic photosensitive member (photosensitive member (11)), the charging unit (12), the exposing unit (13), the developing unit (14), and the transferring unit of the present invention described above. (16) and a cleaning means (17) having a cleaning blade for rubbing the photoreceptor (11).
Hereinafter, an image forming apparatus used in the present invention will be described with reference to the drawings.

FIG. 5 is a schematic diagram for explaining an image forming apparatus according to the present invention, and modifications as will be described later also belong to the category of the present invention.
In FIG. 5, a photoreceptor (11) is an electrophotographic photoreceptor on which a cross-linked resin surface layer is laminated. Although the photoconductor (11) has a drum shape, it may be a sheet or an endless belt.

  As the charging means (12), known means such as a corotron, a scorotron, a solid state charger (solid state charger), and a charging roller are used. The charging means (12) is preferably used in contact with or close to the photoreceptor from the viewpoint of reducing power consumption. In particular, in order to prevent contamination of the charging means (12), the charging mechanism is arranged in the vicinity of the photoreceptor (11) so as to have an appropriate gap between the surface of the photoreceptor (11) and the charging means (12). Is desirable.

  As the transfer means (16), the above charger can be generally used, but a combination of a transfer charger and a separation charger is effective.

  Light sources used for the exposure means (13), the charge removal means (1A), etc. include fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light emitting diodes (LEDs), semiconductor lasers (LDs), and electroluminescence (ELs). Examples of luminescent materials such as Various kinds of filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used to irradiate only light in a desired wavelength range.

  The toner (15) developed on the photoreceptor (11) by the developing means (14) is transferred to a printing medium (18) such as printing paper or an OHP slide, but not all is transferred. Toner remaining on the photoreceptor (11) is also generated. Such toner is removed from the photoreceptor (11) by the cleaning means (17). The cleaning means (17) may be a rubber cleaning blade, a brush such as a fur brush, a mag fur brush, or the like.

  When positive (negative) charging is performed on the photoconductor (11) and image exposure is performed, a positive (negative) electrostatic latent image is formed on the surface of the photoconductor (11). A positive image can be obtained by developing this with negative (positive) toner (electrodetection fine particles), and a negative image can be obtained by developing with positive (negative) toner. A known method is applied to the developing means (14), and a known method is also used for the charge eliminating means (1A).

  The toner transferred to the print medium (18) is fixed by the fixing means (19).

  The above electrophotographic process exemplifies an embodiment of the present invention, and other embodiments are of course possible. In the light irradiation process, image exposure and static elimination exposure are illustrated. In addition, a pre-transfer exposure, an image exposure pre-exposure, a pre-cleaning exposure, and other known light irradiation processes are provided to irradiate the photosensitive member with light. You can also. For example, pre-cleaning exposure may be performed from the support side or from the photosensitive layer side. In addition, image exposure and neutralizing light irradiation may be performed from the support side.

  Further, the image forming means as described above may be fixedly incorporated in a copying machine, a facsimile, or a printer, but may be incorporated in these apparatuses in the form of a process cartridge. There are many types of process cartridges, but a typical example is shown in FIG. The reference numerals in FIG. 6 are assigned corresponding to those shown in FIG. The photoconductor (11) has a drum shape, but may be a sheet or endless belt.

FIG. 7 shows another example of the image forming apparatus according to the present invention.
In this image forming apparatus, a charging unit (12), an exposure unit (13), black (Bk), cyan (C), magenta (M), and yellow (Y) are provided around the photoconductor (11). Developing means (14Bk, 14C, 14M, 14Y), an intermediate transfer member (1F) as an intermediate transfer belt, and a cleaning means (17) are arranged in this order. Here, the subscripts Bk, C, M, and Y shown in the figure correspond to the color of the toner, and are added or omitted as appropriate.

The photoreceptor (11) is an electrophotographic photoreceptor on which a crosslinkable resin surface layer is laminated.
Each color developing means (14Bk, 14C, 14M, 14Y) can be controlled independently, and only the color developing means for image formation is driven. The toner image formed on the photoreceptor (11) is transferred onto the intermediate transfer belt (1F) by the first transfer means (1D) disposed inside the intermediate transfer belt (1F). The first transfer means (1D) is arranged so as to be able to come into contact with and separate from the photoreceptor (11), and the intermediate transfer belt (1F) is brought into contact with the photoreceptor (11) only during the transfer operation. Each color image is sequentially formed, and the toner images superimposed on the intermediate transfer belt (1F) are collectively transferred to the printing medium (18) by the second transfer means (1E) and then fixed by the fixing means (19). The image is formed by fixing.
The second transfer means (1E) is also arranged so as to be able to contact and separate from the intermediate transfer belt (1F), and abuts on the intermediate transfer belt (1F) only during the transfer operation.

  In the transfer drum type image forming apparatus, the toner image of each color is sequentially transferred onto the transfer material (print medium (18)) electrostatically attracted to the transfer drum, so there is a limitation on the transfer material that cannot be printed on cardboard. On the other hand, the image forming apparatus of the intermediate transfer system as shown in FIG. 7 has a feature that the toner images of the respective colors are superimposed on the intermediate transfer body (1F) and thus are not limited by the transfer material. Such an intermediate transfer method is not limited to the apparatus shown in FIG. 7, but can be applied to the image forming apparatus shown in FIGS. 5 and 6 described above and FIG. 8 described later (a specific example is shown in FIG. 9).

FIG. 8 shows another example of the image forming apparatus according to the present invention.
This image forming apparatus is a type using four colors of yellow (Y), magenta (M), cyan (C), and black (Bk) as toners, and an image forming unit is provided for each color. In addition, photoconductors for each color (11Y, 11M, 11C, 11Bk (collectively referred to as photoconductor (11)) are provided.

  The photoreceptor (11) used in this image forming apparatus is an electrophotographic photoreceptor on which a cross-linked resin surface layer is laminated.

  Further, a charging unit (12), an exposure unit (13), a developing unit (14), a cleaning unit (17), and the like are disposed around each photoconductor (11Y, 11M, 11C, 11Bk). Further, a transfer transfer belt (1F) as a transfer material carrier that comes in contact with and separates from each transfer position of each photoconductor (11Y, 11M, 11C, 11Bk) arranged on a straight line is hung by a driving means (1C). Has been passed. Transfer means (16Y, 16M, 16C, 16Bk) are disposed at transfer positions facing the respective photoconductors (11Y, 11M, 11C, 11Bk) with the conveyance transfer belt (1F) interposed therebetween.

  The tandem type image forming apparatus as shown in FIG. 8 has a photoconductor (11Y, 11M, 11C, 11Bk) for each color, and print media (11F, 11M, 11C, 11Bk) that hold the toner images of the respective colors on the transfer transfer belt (1F) Since the transfer is sequentially performed in step 18), it is possible to output a full-color image much faster than a full-color image forming apparatus having only one photoconductor.

<Supply of solid lubricant>
In the present invention, as shown in FIG. 10, as the zinc stearate supply means for supplying the lubricant (3A) to the surface of the photoreceptor (11), the lubricant supply means (3C) is provided for the above image forming apparatus. Also good.

  This lubricant supply means (3C) has a fur brush (3B) as an application member, a solid lubricant (3A), and a pressure spring (3D) for pressing the lubricant in the fur brush direction.

  The solid lubricant (3A) at this time is zinc stearate molded into a bar shape. The fur brush (3B) has a brush tip in contact with the surface of the photoconductor (11), and by rotating about the shaft, the solid lubricant (3A) is pumped up to one end of the brush to contact the surface of the photoconductor (11). It is carried on the brush to the contact position and input to the surface of the photoreceptor.

  Further, even if the solid lubricant (3A) is scraped off by the fur brush (3B) over time, the solid lubricant (3D) is solid at a predetermined pressure so as not to come into contact with the fur brush (3B). The lubricant (3A) is pressed toward the fur brush (3B). As a result, even a small amount of the solid lubricant (3A) is always uniformly pumped up to the fur brush (3B).

  Further, a solid lubricant fixing means for improving the fixability of the solid lubricant adhered to the surface of the photoreceptor (11) may be provided. This means includes means for providing a plate such as a cleaning blade by a trailing method, and means for pressing a rubber roll against the photosensitive member.

  Examples of the solid lubricant (3A) include lead oleate, zinc oleate, copper oleate, zinc stearate, cobalt stearate, iron stearate, copper stearate, zinc palmitate, copper palmitate, zinc linolenate. Fatty acid metal salts such as polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, polytrifluorochloroethylene, dichlorodifluoroethylene, tetrafluoroethylene-ethylene copolymer, tetrafluoroethylene-oxafluoropropylene copolymer Fluorine-based resins such as coalesced are mentioned, but a metal stearate having a large effect of reducing the friction coefficient of the photoreceptor (11) and zinc stearate are more preferable.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited to a following example. Note that “parts” used in the examples all represent parts by weight (parts by mass).

Example 1
A cylindrical aluminum support (wall thickness: 0.8 mm, length: 340 mm, outer diameter: 30 mmφ) is dip-coated using the following undercoat layer coating solution, and the film thickness after heat drying is 3. An undercoat layer was formed so as to have a thickness of 5 μm.

-Undercoat layer coating solution-
Alkyd resin 6 parts by weight (Beckosol 1307-60-EL, manufactured by Dainippon Ink & Chemicals, Inc.)
Melamine resin 4 parts by weight (Super Becamine G-821-60, manufactured by Dainippon Ink & Chemicals, Inc.)
Titanium oxide (CR-EL: Ishihara Sangyo) 40 parts by weight Methyl ethyl ketone 50 parts by weight

  On this undercoat layer, it was dip-coated in a charge generation layer coating solution containing a bisazo pigment having the following structure and dried by heating to form a charge generation layer having a thickness of 0.2 μm.

-Coating solution for charge generation layer-
2.5 parts by weight of a bisazo pigment of the following structural formula (A)

Polyvinyl butyral (XYHL, manufactured by UCC) 0.5 parts by weight Cyclohexanone 200 parts by weight Methyl ethyl ketone 80 parts by weight

  On this charge generation layer, the following charge transport layer coating solution was used for dip coating and dried by heating to form a charge transport layer having a thickness of 22 μm.

-Coating liquid for charge transport layer-
10 parts by weight of bisphenol N type polycarbonate (Panlite TS2050, manufactured by Teijin Chemicals Ltd.)
10 parts by weight of a low molecular charge transport material having the following structural formula (B)

Tetrahydrofuran 80 parts by weight 1% silicone oil in tetrahydrofuran 0.2 parts by weight (KF50-100CS, manufactured by Shin-Etsu Chemical Co., Ltd.)

  Next, the same coating solution as that for the charge transport layer was spray-coated on the charge transport layer as a surface layer coating solution, followed by heating and drying to obtain a surface layer having a thickness of 5 μm.

The spray coating conditions are shown below.
Nozzle-support distance: 50 mm
Atomization air pressure: 2.5 kg / cm ²
Air flow rate: 15.0L / min
Discharge rate: 0.06 ml / s
Spray gun moving speed: 5.4 mm / s
Drum rotation speed: 80 rpm
Touch drying time: 10 minutes Number of sprays: 1 time Mask type placed on the drum front: Mask # 1 (Table 1)
Drum-mask distance: 10 mm

(Example 2)
In Example 1, an electrophotographic photosensitive member was obtained in the same manner as in Example 1 except that the mask used for coating the surface layer was changed to mask # 2 (Table 1) and the discharge amount was changed to 0.10 ml / s. It was.

(Example 3)
In Example 1, an electrophotographic photosensitive member was obtained in the same manner as in Example 1 except that the mask used for coating the surface layer was changed to mask # 3 (Table 1).

(Example 4)
In Example 3, an electrophotographic photosensitive member was obtained in the same manner as in Example 3 except that the surface layer coating solution was changed as follows.

-Surface layer coating solution-
4 parts by weight of polycarbonate resin (Z polycarbonate, viscosity average molecular weight; 50,000, manufactured by Teijin Chemicals Ltd.)
3 parts by weight of low molecular charge transport material of the structural formula (B) Fine particles: 5 parts by weight of a dispersion of crosslinked styrene-acrylic fine particles (SX866 (A), manufactured by JSR Corporation)
Cyclohexanone 80 parts by weight Tetrahydrofuran 280 parts by weight

(Example 5)
In Example 3, an electrophotographic photosensitive member was obtained in the same manner as in Example 3 except that the surface layer coating solution was changed as follows.

-Surface layer coating solution-
4 parts by weight of polycarbonate resin (Z polycarbonate, viscosity average molecular weight; 50,000, manufactured by Teijin Chemicals Ltd.)
3 parts by weight of low molecular charge transport material of the structural formula (B) Fine particles: 1.4 parts by weight of silica fine particles (KMPX-100, average primary particle size: 0.1 μm, manufactured by Shin-Etsu Chemical Co., Ltd.)
Cyclohexanone 80 parts by weight Tetrahydrofuran 280 parts by weight

(Example 6)
In Example 3, an electrophotographic photosensitive member was obtained in the same manner as in Example 3 except that the surface layer coating solution was changed as follows.

-Surface layer coating solution-
4 parts by weight of polycarbonate resin (Z polycarbonate, viscosity average molecular weight; 50,000, manufactured by Teijin Chemicals Ltd.)
Low molecular charge transport material of the structural formula (B) 3 parts by weight Fine particles: α-alumina 1.4 parts by weight (Sumicorundum AA-03, manufactured by Sumitomo Chemical Co., Ltd.)
Cyclohexanone 80 parts by weight Tetrahydrofuran 280 parts by weight

(Example 7)
In Example 3, an electrophotographic photosensitive member was obtained in the same manner as in Example 3 except that the surface layer coating solution was changed to a crosslinked surface layer coating solution having the following constitution. After coating the surface layer, UV curing was performed while rotating the drum at a distance of 120 mm from the drum and the UV curing lamp. The illuminance of the UV curing lamp at this position was 550 mW / cm ² (UV integrated light meter UIT-150, measured value by Ushio Inc.). The rotation speed of the drum was 25 rpm, and when UV curing was performed, water at 30 ° C. was circulated in the aluminum drum and UV curing was continued for 3 minutes. Then, it heat-dried at 130 degreeC for 30 minutes. As a result, an electrophotographic photosensitive member provided with a 6 μm cross-linked resin surface layer was obtained.

-Surface layer coating solution (crosslinked surface layer coating solution)-
9 parts by weight of a tri- or higher functional radical polymerizable monomer having no charge transport structure (Trimethylolpropane triacrylate (KAYARAD TMPTA, manufactured by Nippon Kayaku)
Molecular weight: 382, number of functional groups: trifunctional, molecular weight / number of functional groups = 99)
9 parts by weight of radically polymerizable compound having a charge transporting structure (2- [4 ′-(di-p-tolyl-amino) -biphenyl-4-yl] -ethyl acrylate) (the following structural formula (C))

2 parts by weight of photopolymerization initiator (1-hydroxy-cyclohexyl-phenyl-ketone (Irgacure 184, manufactured by Ciba Specialty Chemicals))
Tetrahydrofuran 100 parts by weight

(Example 8)
In Example 7, an electrophotographic photosensitive member was obtained in the same manner as in Example 7 except that the following materials were added to the surface layer coating solution.
Alumina filler (Sumicorundum AA03, average primary particle size: 0.3 μm, manufactured by Sumitomo Chemical Co., Ltd.): 8 parts by weight Polycarboxylic acid compound (low molecular weight unsaturated polycarboxylic acid polymer solution, BYK-P104, nonvolatile content 50% Manufactured by BYK Chemie): 0.2 parts by weight

(Comparative Example 1)
In Example 1, an electrophotographic photosensitive member was obtained in the same manner as in Example 1 except that the mask was removed when the surface layer was applied.

(Comparative Example 2)
In Example 4, an electrophotographic photosensitive member was obtained in the same manner as in Example 4 except that the mask was changed to mask # 4 (Table 1) when the surface layer was applied.

(Comparative Example 3)
In Example 6, an electrophotographic photosensitive member was obtained in the same manner as in Example 6 except that the mask was changed to mask # 5 (Table 1) when the surface layer was applied.

(Comparative Example 4)
In Example 8, an electrophotographic photosensitive member was obtained in the same manner as in Example 8 except that the discharge rate at the time of coating the surface layer was changed to 0.12 ml / s.

[Measurement method and evaluation method]
The electrophotographic photoreceptor sample produced as described above was measured and evaluated as follows.
(1) Measurement of photoconductor surface shape Using a surface roughness / contour shape measuring machine (Tokyo Seimitsu Co., Surfcom 1400D, configuration shown in FIG. 11), the axial surface of the electrophotographic photoconductor is subjected to filtered centerline waviness measurement. Measure the waviness curve under the conditions of measurement length 50.0mm, cut-off wavelength 2.5mm to 8.0mm, measurement speed 0.6mm / s, cut-off type is Gaussian correction, tilt correction is least squares linear approximation Selected. From this waviness curve, the arithmetic average waviness Wa of the surface layer and the average length WSm of the waviness curve element were calculated.
A total of 12 measurement points were measured: 3 points at the upper end, the center, and the lower end in the longitudinal direction of the photoconductor, and 4 points every 90 ° in the circumferential direction, and the average value of 12 points was taken as the value.

  The surface shapes of the electrophotographic photosensitive members of Example 1 and Comparative Example 1 are measured, the roughness component is cut off with a cutoff value of 2.5 mm of the λc contour curve filter, and the cutoff value of the λf contour curve filter is 8. The undulation curves obtained by blocking the wavelength component longer than the undulation at 0 mm are shown in FIGS. 12 and 13, respectively.

(2) Toner slip measurement / evaluation method (measurement method)
As shown in FIG. 14, the toner slippage measurement in this example was performed by a process of collecting the toner adhering to the photoreceptor (11) with the cleaning blade (35). The toner (34) that has passed through the cleaning blade (35) is a white felt of 1 mm thickness and 8 mm × 310 mm (manufactured by Ashiya Co., Ltd., hereinafter referred to as “through toner catcher”) (33) downstream of the cleaning blade, upstream of the developer opening. And collected by bringing it into contact with the photoreceptor (11).
Actual measurement was performed according to the following procedure. That is, among the photoreceptor sets of imgio Neo C455 manufactured by Ricoh, a photoreceptor set for slip-through strength measurement was obtained by removing the cleaning brush, the charging roller cleaner, and the rod-shaped zinc stearate. The mounting position was the black development station (FIG. 14).
Among the bias applied to the charging roller of Image Neo C455, the DC bias was adjusted so that the charged potential of the photoconductor (11) was -700V. Next, the amount of writing light was adjusted so that the exposure portion potential was −250V. In this state, a solid pattern was written with various development biases.
The toner input to the photoconductor (11) before transfer is collected with a transparent adhesive tape (Nitto Denko Corporation, Printac C), and the image density of the collected tape is measured with a reflection spectrodensitometer (Canon ITEC, X- RITE 939), and the development bias was changed to a density of 1.0.
Next, a 2 mm thick linear sponge tape (Sumitomo 3M, Scotch tape 4016) is passed through the upper end of the opening of the developing means, and the toner catcher (33) (felt of 8 mm × 310 mm with a thickness of 1 mm) Manufactured)). This was attached to the main body.
The cleaning blade (35) is a genuine Imagio Neo C455 product, a cleaned photoconductor (11) is attached, and a test pattern image (36) of A4 size with an image density of 5% is continuously obtained in a 23 ° C. and 55% RH environment. 50 sheets were printed on copy paper (My Paper A4, manufactured by NBS Ricoh Company). As the toner, a genuine polymerized toner (IPSIO toner type ° 9800) was used.

(Evaluation methods)
After printing, the slip-through toner catcher (33) was collected, and the felt contamination was visually observed and evaluated according to the following criteria.
-Evaluation criteria-
○: Slightly dirty △: Slightly dirty ×: Apparently severely contaminated

(3) Blade squeeze evaluation A color copier (image Neo Neo C455 manufactured by Ricoh) was used for blade squeeze evaluation of the image forming apparatus. A small microphone was mounted on the back side of the front panel of the color copying machine at a position closest to the mounting position of the photosensitive unit to be evaluated. This microphone was connected to a personal computer, and the driving sound of the electrophotographic photosensitive member (11) was recorded by acoustic analysis software (EFT Software, FFT Wave Version 7.7). The quality of the noise was judged by comparing the frequency characteristics of the sound obtained by Fourier transforming the obtained acoustic data. After driving for 14 hours, the driving sound of the electrophotographic photosensitive member (11) was recorded using a microphone, and the frequency characteristics of the recorded data were compared.

An example of the obtained data is shown in FIGS.
FIG. 15 shows the frequency characteristics of the operating sound in a blank state in which the photosensitive unit is not set. No peak is seen around 5000 Hz.
FIG. 16 shows frequency characteristics of operating sound when an electrophotographic photosensitive member (for example, Comparative Example 1) having a surface layer that is not the present invention is mounted and the electrophotographic photosensitive member is driven. In this case, a blade squeal was heard. From the frequency characteristics of the recorded data, a peak of acoustic power is seen at about 5 kHz.
FIG. 17 is a graph showing the frequency characteristics of operating sound when the electrophotographic photosensitive member (for example, Example 1) having a surface layer corresponding to the present invention is replaced. In the frequency characteristics of the recorded data, the sound power peak disappears at about 5 kHz.
When recording the driving sound of the electrophotographic photosensitive member, only one photosensitive unit to be evaluated was mounted in the color copying machine, and the developing unit and the transfer unit were excluded.

Regarding the blade noise, an acoustic power (dB) of 5243 Hz was measured and evaluated according to the following criteria.
-Evaluation criteria-
○: −70 dB or less (good)
Δ: -60 to -70 dB (no problem level)
×: −60 dB or more (level that feels unpleasant sound)

(4) Image evaluation Five halftone patterns and blank paper patterns depicting 4 dots x 4 dots in an 8 x 8 matrix with a pixel density of 600 dpi x 600 dpi are printed in succession 5 sheets at a time. The background stain of the blank paper pattern after output was evaluated visually according to the following criteria.
-Evaluation criteria-
○: Extremely good △: No problem ×: Dull feel.
In addition, the state of the cleaning blade in the durability test was observed, and the occurrence of cracks and chatter was also observed.

  Table 2 shows the measurement results of the photoreceptor surface shape, and Table 3 shows the results of toner slipping, blade noise, and image evaluation.

  From the above results, in the electrophotographic photosensitive member in which at least the photosensitive layer and the surface layer are sequentially laminated on the conductive support, the surface shape in the axial direction of the electrophotographic photosensitive member is measured by the contour curve method, and the λc contour curve filter An arithmetic average waviness Wa in a waviness curve obtained by cutting off a roughness component with a cut-off value of 2.5 mm and blocking a wavelength component longer than waviness with a cut-off value of 8.0 mm of the λf contour curve filter is 0.08 μm to An electrophotographic photosensitive member having an average length WSm of 0.20 μm and a waviness curve element of 3.0 mm to 6.0 mm is free from chatter, squeal, and scratching of the cleaning blade, and has good cleaning properties over a long period of time. And having excellent durability and electrical characteristics. It has also been clarified that the image forming method, the image forming apparatus, and the process cartridge using the photoconductor of the present invention have high performance and high reliability.

  Although the present invention has been described with the embodiments shown in the drawings, the present invention is not limited to the embodiments shown in the drawings, and other embodiments, additions, modifications, deletions, etc. Can be changed within the range that can be conceived, and any embodiment is included in the scope of the present invention as long as the effects and advantages of the present invention are exhibited.

11, 11Bk, 11C, 11M, 11Y Electrophotographic photosensitive member (photosensitive member)
12, 12Bk, 12C, 12M, 12Y Charging means 13, 13Bk, 13C, 13M, 13Y Exposure means 14, 14Bk, 14C, 14M, 14Y Developing means 15 Toner 16, 16Bk, 16C, 16M, 16Y Transfer means 17, 17Bk, 17C, 17M, 17Y Cleaning means 18 Print media (printing paper, slide for OHP)
DESCRIPTION OF SYMBOLS 19 Fixing means 1A Static elimination means 1C Drive means 1D 1st transfer means 1E 2nd transfer means 1F Intermediate transfer body 21 Conductive support body 24 Undercoat layer 25 Charge generation layer 26 Charge transport layer 28 Crosslinkable resin surface layer (surface layer)
32 Developing roller 33 Bypass toner catcher 34 Bypass toner 35 Cleaning blade 36 Print image 3A Solid lubricant 3B Fur brush 3C Lubricant supply means 3D Pressure spring 42 Jig with a probe for measuring surface roughness 43 Jig 42 Moving means for moving along the measuring object 44 Surface roughness meter 45 Personal computer for signal analysis A Spray gun B Substrate M Mask Mw Opening

JP 2000-66424 A JP 2000-171990 A JP-A-53-092133 JP-A-52-026226 Japanese Patent Laid-Open No. 02-139666 Japanese Patent Laid-Open No. 02-150850 JP 2003-215829 A Japanese Patent Laid-Open No. 2003-5606 JP 2010-134594 A JP 2010-145793 A

Claims (11)

In an electrophotographic photosensitive member having at least a photosensitive layer and a surface layer on a conductive support,
The surface shape of the electrophotographic photosensitive member in the axial direction is measured by a contour curve method, the roughness component is cut off with a cutoff value of 2.5 mm of the λc contour curve filter, and the cutoff value of the λf contour curve filter is 8.0 mm. In the undulation curve obtained by blocking the wavelength component longer than the undulation, the arithmetic average undulation Wa is 0.08 μm to 0.20 μm, and the average length WSm of the undulation curve element is 3.0 mm to 6.0 mm. An electrophotographic photoreceptor characterized by the above.   The electrophotographic photosensitive member according to claim 1, wherein the surface layer contains filler fine particles.   The electrophotographic photosensitive member according to claim 2, wherein the filler fine particles are inorganic fillers.   The electrophotographic photosensitive member according to claim 2, wherein the filler fine particles are made of alumina.   The surface layer is made of a crosslinkable resin, and the crosslinkable resin has a structural unit derived from a crosslinkable charge transport material having a triarylamine structure. Electrophotographic photoreceptor.   The electrophotographic photosensitive member according to claim 1, wherein the surface layer is coated by a spray coating method.   The electrophotographic photosensitive member according to claim 6, wherein the surface layer is spray-coated through a mask having openings arranged at a constant pitch in an axial direction of the electrophotographic photosensitive member. .   The electrophotographic photosensitive member according to any one of claims 1 to 7, a charging unit, an exposure unit, a developing unit, a transfer unit, and a cleaning unit having a cleaning blade for rubbing the electrophotographic photosensitive member, An image forming apparatus comprising:   The image forming apparatus according to claim 8, wherein the developing unit uses spherical toner having an average circularity of 0.95 or more and 0.99 or less.   The image forming apparatus according to claim 8, wherein the developing unit has a developing station of at least two colors or more, is a tandem type, and further develops using polymerized toner.   A process cartridge that can be attached to and detached from an image forming apparatus main body including at least the electrophotographic photosensitive member according to claim 1, a developing unit, and a cleaning unit, wherein the cleaning unit is the electrophotographic photosensitive member. A process cartridge comprising a cleaning blade for rubbing.