JP6541440B2 - Electrophotographic photosensitive member, process cartridge and electrophotographic apparatus - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member, a process cartridge and an electrophotographic apparatus.

  The surface of the electrophotographic photosensitive member is required to have durability (abrasion resistance and the like) against external forces such as charging and cleaning because external and mechanical external forces such as cleaning are applied.

  In response to this demand, conventionally, improved techniques such as using a resin (such as a curable resin) having high abrasion resistance for the surface layer of the electrophotographic photosensitive member have been used.

  On the other hand, as a problem caused by enhancing the wear resistance of the surface of the electrophotographic photosensitive member, there is a decrease in cleaning performance due to high dynamic friction coefficient and high rotational torque.

  As a technique for such a subject, in Patent Document 1, when the surface roughness is represented by Rz JIS on the surface of the electrophotographic photosensitive member, the number of convex portions having a height of 1/2 x Rz JIS or more measures 12 mm in length. An electrophotographic photosensitive member having 30 or more and 300 or less per unit is disclosed.

JP, 2010-160184, A

  However, the technology disclosed in Patent Document 1 has a relatively large torque reduction effect and is less likely to cause cleaning failure etc., but there is room for improvement in terms of maintainability of the convex portion (convex shape portion) after repeated use. Remaining.

  An object of the present invention is to provide an electrophotographic photosensitive member excellent in maintainability of a convex portion, a process cartridge having the electrophotographic photosensitive member, and an electrophotographic apparatus.

The present invention is a cylindrical electrophotographic photosensitive member having a support and a photosensitive layer formed on the support, and the surface of the electrophotographic photosensitive member has a plurality of convex portions independent of one another. ,
The width of the convex shaped portion in the axial direction of the electrophotographic photosensitive member is 10 μm or more and 100 μm or smaller, and the convex shaped portion has a height from the tip side in the rotation direction of the electrophotographic photosensitive member to the highest point a gradually becomes higher shape, and the maximum slope of the gradually becomes higher shape portion Ri der 70 ‰ or less,
The convex portion has an intersection formed by two straight lines, two curves, or one straight line and one curve on the tip side in the rotational direction of the electrophotographic photosensitive member,
The straight line or the curve forming the intersection point is directed toward the intersection point from the straight line or two points on the curve whose distance to the straight line A passing through the intersection point is the circumferential direction of the electrophotographic photosensitive member , The distance to the straight line A gradually decreases,
It said axial width is an electrophotographic photoconductor, wherein Rukoto determined from the two points.

  Further, the present invention integrally supports the electrophotographic photosensitive member and a cleaning unit having a cleaning member disposed in contact with the electrophotographic photosensitive member, and is detachably attachable to the electrophotographic apparatus main body. It is a cartridge.

  Further, the present invention is characterized by comprising the above-mentioned electrophotographic photosensitive member, and a cleaning unit having a charging unit, an exposure unit, a developing unit, a transfer unit, and a cleaning member disposed in contact with the electrophotographic photosensitive member. It is an electrophotographic apparatus.

  According to the present invention, it is possible to provide an electrophotographic photosensitive member excellent in maintainability of a convex portion, a process cartridge having the electrophotographic photosensitive member, and an electrophotographic apparatus.

FIG. 4 is a view schematically showing a shape of a convex portion on the surface of an electrophotographic photosensitive member as viewed from above and a shape of a cross section in a circumferential direction of the convex portion. It is a figure which shows the example of a fitting, and a figure which shows typically the relationship of a reference plane, a convex-shaped part, etc. FIG. It is a figure which shows the example of a shape when the convex-shaped part of the surface of an electrophotographic photosensitive member is seen from upper direction. It is a figure which shows the example of the shape of the cross section of the circumferential direction of the convex-shaped part of the surface of an electrophotographic photosensitive member. FIG. 2 is a view showing an example of a pressure contact shape transfer processing apparatus for forming a convex portion on the surface of an electrophotographic photosensitive member. FIG. 1 is a view showing an example of an electrophotographic apparatus provided with a process cartridge having the electrophotographic photosensitive member of the present invention. It is a figure which shows the mold used in the manufacture example of an electrophotographic photosensitive member. It is a figure which shows the mold used in the manufacture example of an electrophotographic photosensitive member. It is a figure which shows the mold used in the manufacture example of an electrophotographic photosensitive member. It is a figure which shows the mold used in the manufacture example of an electrophotographic photosensitive member. It is a figure which shows the mold used in the manufacture example of an electrophotographic photosensitive member.

  The electrophotographic photosensitive member of the present invention is a cylindrical electrophotographic photosensitive member having a support and a photosensitive layer formed on the support, and the surface has a plurality of independent convex portions. There is. The width of the convex portion in the axial direction (hereinafter, also simply referred to as “axial direction”) of the electrophotographic photosensitive member is 10 μm to 100 μm. In addition, the convex portion has a shape in which the height gradually increases from the tip end side of the rotation direction of the electrophotographic photosensitive member (hereinafter, also simply referred to as “rotation direction”) to the highest point. The maximum slope of the raised feature is less than 70 ‰.

  As a result of examinations by the present inventors, it was found that, by arranging the above-mentioned specific convex shape portion on the surface of the electrophotographic photosensitive member, the maintainability of the convex shape portion when used repeatedly is dramatically improved. .

  By providing a convex portion with an axial width of 10 μm to 100 μm on the surface of the electrophotographic photosensitive member, the durability of the convex portion to the load when the cleaning unit such as a cleaning blade passes the convex portion is enhanced. . As a result, even when used repeatedly, the convex portion hardly changes due to wear. Also, the coefficient of friction can be reduced. The width in the axial direction of the convex portion is more preferably 30 μm or more and 100 μm or less.

  Furthermore, when the maximum slope of the shape portion whose height gradually increases from the tip side in the rotation direction of the electrophotographic photosensitive member toward the highest point is 70 ‰ or less, the cleaning blade or the like passes through the convex shape portion. The load which the convex portion receives from the cleaning blade or the like is suppressed. Therefore, the present inventors think that the maintenance effect of a convex-shaped part is expressed when it uses repeatedly.

  Specifically, the surface of the electrophotographic photosensitive member of the present invention is a convex portion as shown in FIG. 1, for example, and the width in the axial direction of the electrophotographic photosensitive member is 10 μm or more and 100 μm or less, The convex portion has a shape in which the height gradually increases from the tip side in the rotational direction of the electrophotographic photosensitive member to the highest point, and the maximum gradient of the gradually rising portion is 70 or less. A plurality of independent convex portions (hereinafter also referred to as "specific convex portions") are provided. FIG. 1A is a diagram (top view) schematically showing the shape of the convex portion of the surface of the electrophotographic photosensitive member as viewed from above. That is, FIG. 1A shows the shape of the bottom of the convex portion. FIG. 1B is a view (cross-sectional view perpendicular to the axial direction) schematically showing the shape of a cross-section (cross-section perpendicular to the axial direction) in the circumferential direction of the convex portion on the surface of the electrophotographic photosensitive member. is there. Moreover, FIG. 1A and FIG. 1B are cross-sectional profiles after correction which will be described later.

  The convex portion on the surface of the electrophotographic photosensitive member can be observed, for example, using a microscope such as a laser microscope, an optical microscope, an electron microscope, or an atomic force microscope.

As the laser microscope, for example, the following devices can be used.
Ltd. Keyence's ultra-deep shape measuring microscope VK-8550, ultra-deep shape measuring microscope VK-9000, ultra-deep shape measuring microscope VK-9500, VK-X200, Co., Ltd. surface shape measuring system Surface manufactured by Ryoka Systems Co., Ltd. Explorer SX-520DR type machine, scanning confocal laser microscope OLS3000 manufactured by Olympus Co., Ltd., Real color confocal microscope Opretex C130 manufactured by Lasertec Co., Ltd.

As an optical microscope, for example, the following devices can be used.
The digital microscope VHX-500 and the digital microscope VHX-200 made from Keyence Corporation, 3D digital microscope VC-7700 made by OMRON Corporation.

As an electron microscope, for example, the following devices can be used.
3D real surface view microscope VE-9800, 3D real surface view microscope VE-8800, manufactured by Keyence Corporation, scanning electron microscope conventional / Variable Pressure SEM, manufactured by SII Nano Technology Co., Ltd., manufactured by Shimadzu Corporation Scanning electron microscope SUPERSCAN SS-550.

As an atomic force microscope, for example, the following devices can be used.
Nanoscale hybrid microscope VN-8000 manufactured by Keyence Corporation, scanning probe microscope NanoNavi station manufactured by SII Nano Technology Co., Ltd., scanning probe microscope SPM-9600 manufactured by Shimadzu Corporation.

  The independent convex shaped portions on the surface of the electrophotographic photosensitive member of the present invention will be described in detail below. In addition, an independent convex-shaped part shows the state in which each convex-shaped part is distinguished clearly with another convex-shaped part.

  Specifically, first, the surface of the electrophotographic photosensitive member is magnified and observed with a microscope. Since the surface (peripheral surface) of the electrophotographic photosensitive member of the present invention is a curved surface curved in the circumferential direction, the cross-sectional profile of the curved surface is extracted, and the obtained arc is calibrated (fitting). FIG. 2 (a) shows an example of fitting. In FIG. 2A, a solid line 21 is an example of a cross-sectional profile of the surface (curved surface) of the electrophotographic photosensitive member, and a broken line 22 is a curve fitted to the cross-sectional profile 21. The cross-sectional profile 21 is corrected so that the curve 22 becomes a straight line, and a plane obtained by extending the obtained straight line in the longitudinal direction (direction orthogonal to the circumferential direction) of the electrophotographic photosensitive member is used as a reference plane.

  A surface located 0.1 μm above the obtained reference surface and parallel to the reference surface is taken as a second reference surface, and a portion located above the second reference surface is taken as an independent convex portion. FIG. 2B schematically shows the relationship between the reference surface 23, the second reference surface 24, and the convex portion 25. FIG. 2B is a cross-sectional profile after the above correction.

  Then, with respect to the convex shape portion determined to be an independent convex shape portion by the above method, the axial direction of the convex shape portion (the generatrix direction of the electrophotographic photosensitive member) from the cross-sectional profile of the surface on which the convex shape portion is formed. ), The circumferential length of the convex portion, and the height of the convex portion are calculated. FIG. 2C schematically shows the relationship between the reference surface 23, the second reference surface 24, the width L1 of the convex portion, and the height H1 of the convex portion. The width L1 of the convex portion is a distance of an intersection point of the convex portion on the cross-sectional profile and the second reference surface as shown in FIG. 2 (c). The width L1 of the convex portion when the sectional profile after the correction in the circumferential direction and the distance between the intersections is the longest is used as the cross sectional profile after the correction in the circumferential direction. It is a length. The width L1 of the convex portion when the sectional profile in the axial direction and the distance between the intersections is the longest is used as the cross sectional profile is the width in the axial direction of the convex portion. Since the surface of the electrophotographic photosensitive member is not a curved surface bent in the axial direction, a cross-sectional profile as described in FIG. 2C can be obtained without the above correction in the axial direction. Further, on the circumferential cross-sectional profile passing through the highest point (apex) of the convex portion, the shortest distance between the highest point of the convex portion and the second reference surface is the height of the convex portion. Further, the cross section of the convex portion by the second reference surface is the bottom of the convex portion, and the area of the bottom of the convex portion is the area of the convex portion.

  An example of the specific convex portion shown in FIG. 1 will be described. As shown in FIG. 1A, when the specific convex portion is viewed from above, the shape is the point of intersection (tip) 1 formed by two straight lines 11 and 12 on the tip side in the rotational direction of the electrophotographic photosensitive member And the rear end side has a semicircular shape. Further, in the specific convex shaped portion, the distance from the two points 13 and 14 where the distance to the straight line A passing through the intersection point 1 in the circumferential direction is the furthest from the straight line A gradually decreases toward the intersection point 1.

  In the case of a convex portion having an intersection point 1 as shown in FIG. 1A, the axial width can be determined from the two points 13 and 14 farthest from the straight line A passing through the intersection point. Incidentally, the cross section shown in FIG. 2 (c) used when obtaining the axial width of the above-mentioned convex shape portion by the two points 13 and 14 farthest from the straight line A passing through the intersection point 1 shown in FIG. It is an intersection of the convex-shaped part on a profile, and a 2nd reference plane.

  The shape on the tip side of the specific convex shape portion may not have the intersection point 1 shown in FIG. 1, but an intersection point formed by two straight lines as shown in FIG. 1, an intersection point formed by two curves Or a line formed by one straight line and one curve, and the straight line forming the intersection or the curve is a distance to a straight line A passing the intersection in the circumferential direction of the electrophotographic photosensitive member It is preferable from the point of maintainability of the convex shape that the distance to the straight line A is gradually decreased from the most distant straight line or two points on the curve toward the intersection point. Note that if there is no intersection point formed by two straight lines, two curves, or one straight line and one curve in the second reference plane and in the reference plane, then these two straight lines in the reference plane, Two curves, one straight line and one curve, and an intersection point formed are regarded as the two straight lines, two curves, one straight line and one curve, and an intersection point formed.

  In addition, when the specific convex shape portion is projected from the upper direction, an angle θ formed by two straight lines between two points 13 and 14 on the straight line or curve with the greatest distance to the straight line A, to the intersection point 1, The angle formed by the tangents of two curves or the angle formed by one straight line and the tangent of one curve is preferably 58 ° or less from the viewpoint of maintainability of the convex portion. More preferably, it is 56 ° or less. In addition, the tangent of a curve is a tangent in the said intersection on a curve.

  As a shape when a specific convex-shaped part is seen from the top, the shape shown to FIG. 3 (A)-(J) is mentioned, for example. In FIG. 3, the downward direction is the rotation direction of the electrophotographic photosensitive member. 3 (A) to 3 (D) have an intersection formed by two straight lines at the tip in the rotational direction, and the straight line forming the intersection is two on the straight line at which the distance to the straight line A is the most distant. The shape is such that the distance to the straight line A gradually decreases from one point to an intersection point. Also, FIGS. 3E to 3H have an intersection point formed by two curves at the tip in the rotation direction, and the curve forming the intersection point is on the curve with the greatest distance to the straight line A. The distance from the two points of to the straight line A gradually decreases toward the point of intersection. FIG. 3 (I) and FIG. 3 (H) are shapes which do not have an intersection.

  Next, an example of the shape of the cross section in the circumferential direction (the cross section perpendicular to the axial direction) of the specific convex portion will be described. As shown in FIG. 1 (b), the circumferential cross section of the specific convex shape portion has a constant gradient from the tip (intersection 1) in the rotational direction of the convex shape portion toward the highest point (apex) 15 The rear end side in the rotational direction has a dome shape. In FIG. 1B, since the gradually rising shape portion 16 has a constant slope, the maximum slope of the gradually rising shape portion 16 is the height of the highest point 15 of the specific convex shape portion and the specific convex shape portion It can be determined from the moving distance B of the electrophotographic photosensitive member from the tip (intersection point 1) of the point to the highest point 15. Specifically, in FIG. 1B having a constant slope, “height / moving distance B of the highest point 15 of the specific shape portion” is the maximum slope. The height of the highest point 15 of the specific convex shaped portion is the shortest distance between the highest point 15 of the specific convex shaped portion and the second reference surface. If the shape that rises gradually from the tip to the highest point is configured by a curve, the shape that rises gradually is divided into five in the direction perpendicular to the axial direction, and the slope for each section is determined, and The maximum value of is the maximum slope. In the present invention, the maximum slope of the specific convex portion needs to be 70 ‰ or less, preferably 60 ‰ or less. Moreover, it is preferable from the point of reduction of a friction coefficient that a maximum gradient is 10 or more.

Moreover, in the cross section in the circumferential direction, the shape from the tip in the rotational direction of the specific convex shaped portion toward the highest point may be a linear shape as shown in FIG. Although it is good, it is preferable from the point of maintainability of a convex shape that it is linear.
Further, in the circumferential cross section, the shape from the highest point to the rear end side of the convex portion is not particularly limited, but the gradient is larger than the maximum gradient of the gradually rising shape from the tip in the rotational direction to the highest point. It is preferable from the viewpoint of reducing the coefficient of friction.

  Moreover, as a cross-sectional shape of the circumferential direction of a specific convex-shaped part, the shape shown to FIG. 4 (a)-(h) is mentioned, for example. In FIG. 4, the direction toward the left side is the rotation direction of the electrophotographic photosensitive member. FIGS. 4 (a) and 4 (d) are examples in which the shape from the tip in the rotational direction of the specific convex portion toward the highest point is linear, and FIGS. 4 (b) to 4 (c) and 4 (c) FIG.4 (e)-FIG.4 (h) are examples which the shape which goes to the highest point from the front-end | tip of the rotation direction of a specific convex-shaped part is curvilinear form.

  The axial cross section of the specific convex shape portion may be any of a shape formed by a straight line, a shape formed by a curve, and a shape formed by a straight line and a curve. Among them, it is preferable from the viewpoint of the maintainability of the convex portion to be formed of a curve which is expanded in the direction away from the support.

The plurality of specific convex portions provided on the surface of the electrophotographic photosensitive member may be all the same, or may have different shapes, maximum gradients, and heights in combination. Moreover, you may have convex-shaped parts other than a specific convex-shaped part as needed on the surface of an electrophotographic photoreceptor. When the specific convex shape portion and the convex shape portion other than the specific convex shape portion are included, the axial width of all the convex shape portions provided on the surface of the electrophotographic photosensitive member enhances the durability of the convex shape portion. In order to express viewpoints and good cleaning properties, the average value is preferably 10 μm or more, and the average value is preferably 100 μm or less. Furthermore, it is preferable that the axial direction width of all the convex-shaped parts is 10 micrometers or more. The average value of the dimensions of the convex portion such as the width in the axial direction is a square region (area of 250000 μm ² ) of 500 μm on one side at an arbitrary position on the surface of the electrophotographic photosensitive member and a square region of 500 μm on one side. It refers to the arithmetic mean value of the results measured for each of the convex shapes completely contained in the inside. “To place a square area of 500 μm per side at an arbitrary position on the surface of the electrophotographic photosensitive member” means that when the curved surface is corrected to a flat surface, the region that becomes square in the flat surface is the surface of the electrophotographic photosensitive member. It means placing at any position.

  The above-mentioned specific convex shape portion may be formed on the entire surface of the surface of the electrophotographic photosensitive member, or may be formed on a part of the surface of the electrophotographic photosensitive member. When the specific convex portion is formed on a part of the surface of the electrophotographic photosensitive member, it is preferable that a plurality of specific convex portions be formed at least in a contact region with a cleaning member such as a cleaning blade.

  In addition, the area ratio of the specific convex portion on the surface of the surface layer of the electrophotographic photosensitive member is preferably 30% to 70% with respect to the area of the surface of the surface layer.

<Method of forming a convex portion on the surface of the electrophotographic photosensitive member>
By pressing a mold having a concave portion corresponding to the convex portion to be formed onto the surface of the electrophotographic photosensitive member and performing shape transfer, the convex portion can be formed on the surface of the electrophotographic photosensitive member.
FIG. 5 shows an example of a pressure contact shape transfer processing apparatus for forming a convex portion on the surface of an electrophotographic photosensitive member.
According to the press-contact shape transfer processing apparatus shown in FIG. 5, while rotating the electrophotographic photosensitive member 51 which is a workpiece, the mold 52 is continuously brought into contact with the surface (peripheral surface) to pressurize it. A convex portion can be formed on the surface of the photosensitive member 51.

  Examples of the material of the pressing member 53 include metals, metal oxides, plastics, and glass. Among these, stainless steel (SUS) is preferable from the viewpoint of mechanical strength, dimensional accuracy, and durability. The mold 52 is installed on the upper surface of the pressing member 53. Further, a mold 52 is brought into contact with the surface of the electrophotographic photosensitive member 51 supported by the support member 54 by a support member (not shown) and a pressure system (not shown) installed on the lower surface side under a predetermined pressure. Can. The support member 54 may be pressed against the pressure member 53 with a predetermined pressure, or the support member 54 and the pressure member 53 may be pressed against each other.

  In the example shown in FIG. 5, by moving the pressing member 53 in a direction perpendicular to the axial direction of the electrophotographic photosensitive member 51, the surface of the electrophotographic photosensitive member 51 is continuously processed while being driven or rotated. This is an example of Further, the pressing member 53 is fixed, and the support member 54 is moved in a direction perpendicular to the axial direction of the electrophotographic photosensitive member 51, or by moving both the support member 54 and the pressing member 53. The surface of the electrophotographic photosensitive member 51 can also be processed continuously.

  From the viewpoint of efficiently performing shape transfer, it is preferable to heat the mold 52 and the electrophotographic photosensitive member 51.

  As the mold 52, for example, a fine surface processed metal or resin film, a pattern obtained by patterning a resist on the surface of a silicon wafer or the like, a resin film in which fine particles are dispersed, or a resin film having a fine surface shape And those coated with metal.

  Further, in order to make the pressure applied to the electrophotographic photosensitive member 51 uniform, it is preferable to place an elastic body between the mold 52 and the pressing member 53.

<Configuration of Electrophotographic Photoreceptor>
The electrophotographic photosensitive member of the present invention is a cylindrical electrophotographic photosensitive member having a cylindrical support and a photosensitive layer formed on the support.

  The photosensitive layer may be a single layer type photosensitive layer containing the charge transport substance and the charge generation substance in the same layer, or a charge generation layer containing the charge generation substance and a charge transport layer containing the charge transport substance It may be a laminated (functionally separated) photosensitive layer separated into two. From the viewpoint of electrophotographic characteristics, a laminated photosensitive layer is preferred. The laminated photosensitive layer may be a normal photosensitive layer in which the charge generation layer and the charge transport layer are laminated in this order from the support side, or the reverse layer in which the charge transport layer and the charge generation layer are laminated in order from the support It may be a mold photosensitive layer. From the viewpoint of electrophotographic properties, a regular type photosensitive layer is preferred. In addition, the charge generation layer may have a stacked structure, or the charge transport layer may have a stacked structure.

The support is preferably one exhibiting conductivity (conductive support). Examples of the material of the support include metals (alloys) such as iron, copper, gold, silver, aluminum, zinc, titanium, lead, nickel, tin, antimony, indium, chromium, aluminum alloy, stainless steel and the like. In addition, a metal support or a plastic support having a film formed by vacuum deposition using aluminum, an aluminum alloy, an indium oxide-tin oxide alloy or the like can also be used. Further, it is also possible to use a support formed by impregnating plastic or paper with conductive particles such as carbon black, tin oxide particles, titanium oxide particles and silver particles, or a support made of a conductive binder resin.
The surface of the support may be subjected to cutting treatment, roughening treatment, alumite treatment, or the like for the purpose of suppressing interference fringes due to laser light scattering.

  Between the support and the undercoat layer or photosensitive layer (charge generation layer, charge transport layer) described later, for the purpose of suppression of interference fringes due to scattering of laser light, coating of scratches on the support, etc. A layer may be provided.

The conductive layer may be formed by applying a coating liquid for a conductive layer obtained by dispersing carbon black, a conductive pigment, a resistance control pigment, etc. together with a binder resin, and drying the obtained coating film. it can. Moreover, you may add the compound which carries out hardening polymerization by heating, ultraviolet irradiation, radiation irradiation, etc. to the coating liquid for conductive layers. The conductive layer formed by dispersing the conductive pigment, the resistance control pigment and the like tends to have its surface roughened.
The thickness of the conductive layer is preferably 0.2 μm or more and 40 μm or less, more preferably 1 μm or more and 35 μm or less, and more preferably 5 μm or more and 30 μm or less.
Examples of the binder resin used for the conductive layer include polymers of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylic acid ester, methacrylic acid ester, vinylidene fluoride, trifluoroethylene, polyvinyl alcohol, and polyvinyl acetal. And polycarbonate, polyester, polysulfone, polyphenylene oxide, polyurethane, cellulose resin, phenol resin, melamine resin, silicone resin, epoxy resin and the like.
Examples of the conductive pigment and the resistance control pigment include particles of metals (alloys) such as aluminum, zinc, copper, chromium, nickel, silver, stainless steel, and those deposited on the surface of plastic particles. . Alternatively, particles of metal oxides such as zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, indium oxide doped with tin, tin oxide doped with antimony or tantalum, or the like may also be used. it can. One of these may be used alone, or two or more of these may be used in combination. When using in combination of 2 or more types, it may be only mixing, and it may be in the form of solid solution or fusion.

  Between the support or the conductive layer and the photosensitive layer (charge generation layer, charge transport layer), adhesion improvement of the photosensitive layer, coatability improvement, charge injection improvement from the support, electrical breakdown of the photosensitive layer An undercoat layer (intermediate layer) having a barrier function or an adhesive function may be provided for the purpose of protecting the film.

The undercoat layer can be formed by applying a coating solution for undercoat layer obtained by dissolving a resin (binder resin) in a solvent and drying the obtained coating film.
Examples of the resin used for the undercoat layer include polyvinyl alcohol, poly-N-vinylimidazole, polyethylene oxide, ethyl cellulose, ethylene-acrylic acid copolymer, casein, polyamide, N-methoxymethylated 6 nylon, copolymer nylon And gelatin, polyurethane resin, acrylic resin, allyl resin, alkyd resin, phenol resin, epoxy resin and the like.

The undercoat layer may contain metal oxide particles. Examples of metal oxide particles used in the undercoat layer include titanium oxide, zinc oxide, tin oxide, zirconium oxide and aluminum oxide.
The metal oxide particles may be particles in which the surface of the metal oxide particles is treated with a surface treatment agent such as a silane coupling agent.
Examples of the method of dispersing metal oxide particles include a method using a homogenizer, an ultrasonic dispersion machine, a ball mill, a sand mill, a roll mill, a vibration mill, an attritor, and a liquid collision type high speed disperser.

  The undercoat layer may further contain, for example, organic resin particles or a leveling agent for the purpose of adjusting the surface roughness of the undercoat layer or reducing the cracks in the undercoat layer. As organic resin particles, hydrophobic organic resin particles such as silicone particles and hydrophilic organic resin particles such as crosslinkable polymethacrylate resin (PMMA) particles can be used.

  The film thickness of the undercoat layer is preferably 0.05 μm or more and 40 μm or less, and more preferably 0.2 μm or more and 35 μm or less.

  Examples of the charge generating material used in the photosensitive layer include pyrilium and thiapyrilium dyes, phthalocyanine pigments having various central metals and various crystal forms (such as α, β, γ, ε, X type, etc.) and anthanthrone pigments. And dibenzopyrene quinone pigments, pyranthrone pigments, azo pigments such as monoazo, disazo and trisazo, indigo pigments, quinacridone pigments, asymmetric quinocyanine pigments and quinocyanine pigments. These charge generation substances may be used alone or in combination of two or more.

  Examples of charge transport materials used in the photosensitive layer include pyrene compounds, N-alkylcarbazole compounds, hydrazone compounds, N, N-dialkylaniline compounds, diphenylamine compounds, triphenylamine compounds, triphenylmethane compounds, pyrazoline compounds, styryl compounds. Compounds, stilbene compounds and the like can be mentioned.

When the photosensitive layer is a laminated photosensitive layer, the charge generation layer is obtained by applying the coating liquid for charge generation layer obtained by dispersing the charge generation substance with the binder resin and the solvent, and It can be formed by drying. In addition, the charge generation layer may be a deposited film of a charge generation substance.
The mass ratio of the charge generating material to the binder resin is preferably in the range of 1: 0.3 to 1: 4.
Examples of the dispersion treatment method include methods using a homogenizer, ultrasonic dispersion, a ball mill, a vibration ball mill, a sand mill, an attritor, a roll mill and the like.

  The charge transport layer can be formed by applying a charge transport layer coating solution obtained by dissolving a charge transport substance and a binder resin in a solvent, and drying the obtained coating film. In addition, in the case of using a charge transport material having film forming ability alone, the charge transport layer can be formed without using a binder resin.

  Examples of the binder resin used for the charge generation layer and charge transport layer include polymers of vinyl compounds such as styrene, vinyl acetate, vinyl chloride, acrylic acid ester, methacrylic acid ester, vinylidene fluoride and trifluoroethylene, Polyvinyl alcohol, polyvinyl acetal, polycarbonate, polyester, polysulfone, polyphenylene oxide, polyurethane, cellulose resin, phenol resin, melamine resin, silicon resin, epoxy resin and the like can be mentioned.

The thickness of the charge generation layer is preferably 5 μm or less, more preferably 0.1 to 2 μm.
The thickness of the charge transport layer is preferably 5 to 50 μm, and more preferably 10 to 35 μm.

  Further, from the viewpoint of improving the durability of the electrophotographic photosensitive member, it is preferable to configure the surface layer of the electrophotographic photosensitive member with a crosslinked organic polymer.

In the present invention, for example, the charge transport layer on the charge generation layer can be formed of a crosslinked organic polymer as the surface layer of the electrophotographic photosensitive member. In addition, a surface layer composed of a crosslinked organic polymer can be formed as a second charge transport layer or a protective layer on the charge transport layer on the charge generation layer. In addition, the characteristics required for the surface layer composed of the crosslinked organic polymer are both the strength of the film and the charge transport ability, and from that point of view, the charge transport substance or the conductive particles, and the crosslinkable monomer / It is preferable to form a surface layer using an oligomer.
As the charge transporting substance, the above-described charge transporting substance can be used. Moreover, as conductive particles, known conductive particles can be used. As the crosslinkable monomer / oligomer, for example, a compound having a chain polymerizable functional group such as an acryloyloxy group or styryl group, a compound having a sequentially polymerizable functional group such as a hydroxyl group, an alkoxysilyl group or an isocyanate group, etc. It can be mentioned.
From the viewpoint of achieving both strength of the film and charge transportability, it is more preferable to use a compound having both a charge transportable structure (preferably a hole transportable structure) and an acryloyloxy group in the same molecule.
Examples of the method of crosslinking and curing include methods using heat, ultraviolet light, and radiation.
It is preferable that it is 0.1-30 micrometers, and, as for the film thickness of the surface layer comprised with bridge | crosslinking organic polymer, it is more preferable that it is 1-10 micrometers.

  Additives can be added to each layer of the electrophotographic photosensitive member. Examples of the additive include antioxidants, anti-deterioration agents such as ultraviolet light absorbers, organic resin particles such as fluorine atom-containing resin particles and acrylic resin particles, and inorganic particles such as silica, titanium oxide and alumina. Be

<Configuration of Process Cartridge and Electrophotographic Apparatus>
FIG. 6 shows an example of an electrophotographic apparatus provided with a process cartridge having the electrophotographic photosensitive member of the present invention.

In FIG. 6, the cylindrical electrophotographic photosensitive member 81 of the present invention is rotationally driven around the shaft 82 in the direction of the arrow at a predetermined peripheral speed (process speed). The surface of the electrophotographic photosensitive member 81 is uniformly charged to a predetermined positive or negative potential by a charging unit 83 (primary charging unit, for example, a charging roller) in the rotation process. Next, the uniformly charged surface of the electrophotographic photosensitive member 81 receives exposure light (image exposure light) 84 emitted from an exposure unit (image exposure unit) (not shown). In this manner, an electrostatic latent image corresponding to the target image information is formed on the surface of the electrophotographic photosensitive member 81.
The present invention is particularly effective when using a charging unit utilizing discharge.

The electrostatic latent image formed on the surface of the electrophotographic photosensitive member 81 is then developed (regular development or reversal development) with toner (amorphous toner or spherical toner) in the developing means 85 to form a toner image. The toner image formed on the surface of the electrophotographic photosensitive member 81 is transferred onto the transfer material P by a transfer bias from a transfer means (for example, a transfer roller or the like). At this time, the transfer material P is fed out from the transfer material supply means (not shown) between the electrophotographic photosensitive member 81 and the transfer means 86 (contact part) in synchronization with the rotation of the electrophotographic photosensitive member 81 and supplied. Will be sent. Further, to the transfer means, a bias voltage having a polarity opposite to that of the toner charge is applied from a bias power supply (not shown).
The transfer material P to which the toner image has been transferred is separated from the surface of the electrophotographic photosensitive member, conveyed to the fixing means 88, and subjected to the fixing process of the toner image, thereby forming an electrophotographic apparatus as an image formation (print, copy) Printed out.

  The surface of the electrophotographic photosensitive member 81 after the toner image transfer is subjected to removal of extraneous matter such as transfer residual toner by a cleaning means 87 having a cleaning blade disposed in contact with (abutted on) the surface of the electrophotographic photosensitive member 81. Cleaned. Furthermore, the surface of the cleaned electrophotographic photosensitive member 81 is subjected to charge removal processing by pre-exposure light (not shown) from a pre-exposure means (not shown), and then repeatedly used for image formation. When the charging unit 83 is a contact charging unit using a charging roller or the like as shown in FIG. 6, the pre-exposure unit is not necessarily required.

  In the present invention, among the components selected from the electrophotographic photosensitive member 81, the charging unit 83, the developing unit 85, the transfer unit 86, the cleaning unit 87, etc., a plurality of components are accommodated in a container and integrated as a process cartridge. To support. Then, the process cartridge can be detachably configured to an electrophotographic apparatus main body such as a copying machine or a laser beam printer. In FIG. 6, the electrophotographic photosensitive member 81, the charging unit 83, the developing unit 85, and the cleaning unit 87 are integrally supported to form a cartridge, and a guide unit 90 such as a rail of the electrophotographic apparatus main body is used. The process cartridge 89 is detachable from the main body.

  When the electrophotographic apparatus is a copying machine or a printer, the exposure light 84 reads a signal from reflected light or transmitted light from a document or a document by a sensor, converts it into a signal, scans a laser beam according to this signal, The light is emitted by driving the liquid crystal shutter array or the like.

Hereinafter, the present invention will be described in more detail by way of specific examples. In the examples, "parts" means "parts by mass". The electrophotographic photosensitive member is also referred to simply as "photosensitive member" hereinafter.
Moreover, the molds 71-75 used by the Example and the comparative example are sequentially shown in FIGS. 7-11. As shown in FIGS. 7 to 11, the molds 71 to 75 are each provided with a plurality of identical concave portions. FIGS. 7A to 11A are top views schematically showing the molds 71 to 75, respectively. FIGS. 7 (b) to 11 (b) are schematic cross-sectional views in the axial direction of the concave portions of the molds 71 to 75 (cross-sectional views taken along the line S-S 'of FIGS. 7 (a) to 11 (a)) ). 7 (c) to 11 (c) are cross-sectional views in the circumferential direction of the concave portion of the molds 71 to 75 (cross-sectional view taken along the line T-T 'in FIGS. 7 (a) to 11 (a)) It is.

(Production Example of Photoreceptor-1)
An aluminum cylinder having a diameter of 30 mm and a length of 357.5 mm was used as a support (cylindrical support).

Next, 100 parts of zinc oxide particles (specific surface area: 19 m ² / g, powder resistance: 4.7 × 10 ⁶ Ω · cm) as metal oxides are stirred and mixed with 500 parts of toluene, to which a silane coupling agent is added. (Compound name: N-2- (aminoethyl) -3-aminopropyl methyl dimethoxysilane, trade name: KBM602, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.8 part was added and stirred for 6 hours. Thereafter, toluene was distilled off under reduced pressure, and the residue was heated and dried at 130 ° C. for 6 hours to obtain surface-treated zinc oxide particles.
Next, 15 parts of butyral resin (trade name: BM-1, manufactured by Sekisui Chemical Co., Ltd.) and 15 parts of blocked isocyanate (trade name: Sumidure 3175, manufactured by Sumitomo Bayer Urethane Co., Ltd.) as a polyol resin were used as methyl ethyl ketone 73. It was dissolved in a mixed solution of 5 parts and 73.5 parts of 1-butanol. 80.8 parts of the surface-treated zinc oxide particles and 0.8 parts of 2,3,4-trihydroxybenzophenone (manufactured by Tokyo Chemical Industry Co., Ltd.) are added to this solution, and this is added to a glass having a diameter of 0.8 mm. Dispersion was carried out for 3 hours in a 23 ± 3 ° C. atmosphere with a sand mill using beads. After dispersion, 0.01 part of silicone oil (trade name: SH28PA, manufactured by Toray Dow Corning Silicone Co., Ltd.), crosslinked polymethyl methacrylate (PMMA) particles (trade name: TECHPOLYMER SSX-103, manufactured by Sekisui Plastics Co., Ltd.) Then, 5.6 parts of an average primary particle size of 3.0 μm) was added and stirred to prepare a coating solution for undercoat layer.
The undercoat layer coating solution was dip-coated on the support, and the obtained coating film was dried at 160 ° C. for 40 minutes to form an undercoat layer having a thickness of 18 μm.

  Next, 20 parts of hydroxygallium phthalocyanine crystal (charge generation material) having a strong peak at Bragg angles 2θ ± 0.2 °, 7.4 ° and 28.2 ° in CuKα characteristic X-ray diffraction, Sand mill using 1 mm glass beads with 0.2 parts of calixarene compound shown in A), 10 parts of polyvinyl butyral (trade name: S-Lec BX-1, manufactured by Sekisui Chemical Co., Ltd.), and 600 parts of cyclohexanone The mixture was then dispersed for 4 hours, and then 700 parts of ethyl acetate was added to prepare a coating solution for charge generation layer. The coating solution for charge generation layer was dip-coated on the undercoat layer, and the obtained coating film was dried at 80 ° C. for 15 minutes to form a charge generation layer having a film thickness of 0.17 μm.

  Next, 30 parts of a compound represented by the following formula (B) (charge transport substance), 60 parts of a compound represented by the following formula (C) (charge transport substance), 10 parts of a compound represented by the following formula (D) 100 parts of resin (trade name: Iupilon Z400, manufactured by Mitsubishi Engineering Plastics Co., Ltd., bisphenol Z type polycarbonate), 0.02 part of polycarbonate (viscosity average molecular weight Mv: 20000) having the following formula (E), mixed xylene A charge transport layer coating solution was prepared by dissolving in a mixed solvent of 600 parts and 200 parts of dimethoxymethane. This charge transport layer coating liquid was dip coated on the charge generation layer to form a coating film, and the obtained coating film was dried at 100 ° C. for 30 minutes to form a charge transport layer having a thickness of 21 μm. .

(式（Ｅ）中、０．９５及び０．０５は２つの構造単位のモル比（共重合比)である。）

(In the formula (E), 0.95 and 0.05 are the molar ratio (copolymerization ratio) of the two structural units.)

Next, 36 parts of a compound represented by the following formula (F) (charge transporting substance having an acrylic group which is a chain polymerizable functional group), a fine powder of polytetrafluoroethylene resin (RUBLON L-2, manufactured by Daikin Industries, Ltd.) A coating solution for a protective layer was prepared by dispersing and mixing 4 parts of the compound and 60 parts of n-propanol with an ultrahigh pressure disperser.
The coating solution for protective layer was dip-coated on the charge transport layer, and the obtained coating was dried at 50 ° C. for 5 minutes. After drying, the coating film was irradiated with an electron beam while rotating the cylinder for 1.6 seconds under a nitrogen atmosphere at an accelerating voltage of 70 kV and an absorbed dose of 8000 Gy to cure the coating film. Then, heat processing were performed for 3 minutes on the conditions which a coating film becomes 120 degreeC by nitrogen atmosphere. Note that the oxygen concentration from the electron beam irradiation to the heat treatment for 3 minutes was 20 ppm. Next, in the air, heat treatment was performed for 30 minutes under the condition that the coating film reached 100 ° C. to form a protective layer (second charge transport layer) having a thickness of 3.5 μm.

  Thus, a cylindrical electrophotographic photosensitive member (electrophotographic photosensitive member before forming the convex portion) before forming the convex portion on the surface was produced.

· Formation of convex shape portion by mold pressure transfer shape transfer In the pressure transfer shape transfer processing apparatus generally configured as shown in Fig. 5, the mold 71 shown in Fig. 7 is the lower end side of Fig. 7 becomes the tip side in the rotation direction of the electrophotographic photosensitive member. The surface of the electrophotographic photosensitive member before the formation of the convex portion was prepared. The mold shown in FIG. 7 has an axial width (the maximum width in the axial direction when the concave portion on the mold is viewed from above. The same applies hereinafter) X: 40 μm, circumferential length (on the mold This is the maximum length in the circumferential direction when the concave portion is viewed from above, the same applies in the following.) Y: 50 μm, area ratio 50%, depth D: concave portion 4 μm). The area ratio is the ratio of the area of the concave portion to the entire surface when the mold is viewed from above. During processing, the temperature of the electrophotographic photosensitive member and the mold are controlled so that the temperature of the surface of the electrophotographic photosensitive member is 120 ° C., and the electrophotographic photosensitive member and the pressing member are pressed against the mold at a pressure of 7.0 MPa. The electrophotographic photosensitive member was rotated in the circumferential direction to form a convex portion on the entire surface (peripheral surface) of the electrophotographic photosensitive member.

  Thus, an electrophotographic photosensitive member having a convex portion on the surface was produced. This electrophotographic photosensitive member is referred to as “photosensitive member-1”.

Observation of the surface of the electrophotographic photosensitive member The surface of the obtained electrophotographic photosensitive member (photosensitive member-1) is enlarged and observed with a 50 × lens with a laser microscope (trade name: X-100, manufactured by Keyence Corporation) As described above, the determination of the specific convex portion provided on the surface of the electrophotographic photosensitive member was performed. At the time of observation, adjustments were made so that there was no inclination in the longitudinal direction of the electrophotographic photosensitive member, and that the apex of the arc of the electrophotographic photosensitive member was in focus in the circumferential direction. And the image which performed expansion observation was connected by the image connection application, and the information of the whole surface of the electrophotographic photosensitive member was obtained. Moreover, about the obtained result, the image processing height data were selected with attached image analysis software, and the filter processing was performed by filter type median.
The height of the convex portion formed on the surface of the electrophotographic photosensitive member by the above observation, the maximum gradient of the portion toward the highest point from the tip in the rotational direction, the axial width and the circumferential length, and the area The angle of the intersection formed by the straight line and the shape of the cross section in the axial direction were determined. The results are shown in Table 1. The convex portions formed on the surface of the photosensitive member 1 were all the same.

  The surface of the electrophotographic photosensitive member (photosensitive member-1) was observed by the same method as described above using another laser microscope (trade name: X-9500, manufactured by Keyence Corporation). The same results as in the case of using a laser microscope (trade name: X-100, manufactured by Keyence Corporation) were obtained. In the following production examples, a laser microscope (trade name: X-100, manufactured by Keyence Corporation) and 50 times for observation of the surface of an electrophotographic photosensitive member (photosensitive member -2 to 20, photosensitive members -101 to 103) A lens was used.

(Production Example of Photoreceptor-2 to Photoreceptor-20)
An electrophotographic photosensitive member was produced in the same manner as in the production example of the photosensitive member 1 except that the mold 71 was changed to the molds 72 to 74 shown in Table 1 in the production example of the photosensitive member 1. The mold 72 shown in FIG. 8 and the mold 73 shown in FIG. 9 and the mold 74 shown in FIG. 10 are in press-contacting shapes so that the lower side in FIGS. It was installed in the transfer processing device. These electrophotographic photosensitive members are referred to as “photosensitive member-2 to photosensitive member 20”. The surface of the obtained electrophotographic photosensitive member (photosensitive member-2 to photosensitive member 20) was observed in the same manner as in the production example of the photosensitive member-1. The results are shown in Table 1. The convex portions formed on the surfaces of the photosensitive member-2 to the photosensitive member 20 were the same in all the photosensitive members.

(Evaluation of actual equipment of electrophotographic photoreceptor)
Example 1
The photoreceptor 1 was attached to the cyan station of a modified machine of an electrophotographic apparatus (copier) (trade name: iR-ADV C5255) manufactured by Canon Inc., which is an evaluation apparatus, and the test and evaluation were performed as follows. went.
First, the conditions of the charging device and the image exposure device are set so that the dark area potential (Vd) of the electrophotographic photosensitive member is -700 V and the light area potential (Vl) is -200 V under an environment of 23 ° C / 5% RH. The initial potential of the electrophotographic photosensitive member was adjusted.
Next, a polyurethane rubber cleaning blade having a hardness of 77 ° was set to have a contact angle of 28 ° and a contact pressure of 30 g / cm with respect to the surface of the electrophotographic photosensitive member. After outputting 5 sheets of A4 horizontal images having a printing rate of 3% continuously, the image output was repeatedly performed under the condition of temporarily stopping. After outputting 100,000 sheets, the height of the convex portion was measured using the same method as in the initial stage. In addition, a square area (one having an area of 250000 μm ² ) of 500 μm on a side is disposed on the surface of the electrophotographic photosensitive member, and the arithmetic mean value of the measurement results of each convex portion completely included in the square area of 500 μm on one side is It shows in Table 2 as height of a convex-shaped part.

(Examples 2 to 19 and Reference Example 20)
The actual evaluation of the electrophotographic photosensitive member was carried out in the same manner as in Example 1 except that the electrophotographic photosensitive member shown in Table 2 was used. The results are shown in Table 2.

(Production example of photoconductors -101 to 103)
In the production example of the photoreceptor-1, in the same manner as the production example of the photoreceptor-1 except that the mold is changed as shown in Table 3-1, electrophotographic photoreceptors "photoreceptors -101 to 103" are produced did. The mold 75 shown in FIG. 11 was placed in the pressure transfer device so that the lower side of FIG. 11 was on the tip side in the rotational direction of the electrophotographic photosensitive member. Further, the mold 71 shown in FIG. 7 was installed in the pressure transfer type transfer processing apparatus so that the upper side of FIG. The surface of the obtained electrophotographic photosensitive member (photosensitive members -101 to 103) was observed in the same manner as in the production example of the photosensitive member-1. The results are shown in Tables 3-1 and 3-2. The convex portions formed on the surfaces of the photosensitive member -101 to the photosensitive member -103 were the same for all the photosensitive members.

(Comparative Examples 1 to 3)
The actual evaluation of the electrophotographic photosensitive member was performed in the same manner as in Example 1 except that the electrophotographic photosensitive member shown in Table 4 was used. The results are shown in Table 4.

Claims (4)

A cylindrical electrophotographic photosensitive member comprising a support and a photosensitive layer formed on the support, wherein the surface of the electrophotographic photosensitive member has a plurality of independent convex portions.
The width of the convex shaped portion in the axial direction of the electrophotographic photosensitive member is 10 μm or more and 100 μm or smaller, and the convex shaped portion has a height from the tip side in the rotation direction of the electrophotographic photosensitive member to the highest point a gradually becomes higher shape, and the maximum slope of the gradually becomes higher shape portion Ri der 70 ‰ or less,
The convex portion has an intersection formed by two straight lines, two curves, or one straight line and one curve on the tip side in the rotational direction of the electrophotographic photosensitive member,
The straight line or the curve forming the intersection point is directed toward the intersection point from the straight line or two points on the curve whose distance to the straight line A passing through the intersection point is the circumferential direction of the electrophotographic photosensitive member , The distance to the straight line A gradually decreases,
Axial direction of width, an electrophotographic photosensitive member, wherein Rukoto determined from the two points.   An angle formed by the two straight lines or an angle formed by the tangents of the two curves between the straight line at which the distance to the straight line A of the convex portion is the longest or from two points on the curve to the intersection point The electrophotographic photosensitive member according to claim 1, wherein an angle formed by the one straight line and the tangent of the one curve is not more than 58 °. Claim 1 or integrally supports a cleaning means having a cleaning member disposed in contact with the electrophotographic photosensitive member and the electrophotographic photosensitive member according to 2, characterized in that it is detachably mountable to an electrophotographic apparatus main body Process cartridge. An electrophotographic photosensitive member according to claim 1 or 2 , and a cleaning unit having a charging unit, an exposure unit, a developing unit, a transfer unit, and a cleaning member disposed in contact with the electrophotographic photosensitive member. Electrophotographic equipment.

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