JP4921243B2 - Process cartridge and electrophotographic apparatus - Google Patents

Description

  The present invention relates to an electrophotographic photosensitive member, a process cartridge having a charging member for charging the electrophotographic photosensitive member, and an electrophotographic apparatus, and more specifically, a charging roller which is a contact type charging member is brought into contact with the electrophotographic photosensitive member. The present invention relates to a process cartridge and an electrophotographic apparatus for charging the electrophotographic photosensitive member.

  As an electrophotographic photosensitive member, a photosensitive layer (organic photosensitive layer) using an organic material as a photoconductive substance (a charge generating substance or a charge transporting substance) is provided on a support for the advantages of low cost and high productivity. An electrophotographic photosensitive member, so-called organic electrophotographic photosensitive member, is widely used. The organic electrophotographic photoreceptor includes a charge generation layer containing a charge generation material such as a photoconductive dye or a photoconductive pigment, and a charge transport material such as a photoconductive polymer or a photoconductive low molecular weight compound. The mainstream is a photosensitive layer formed by laminating a charge transport layer, that is, a so-called laminated type photosensitive layer. This takes into account the advantages of high sensitivity and material design diversity.

  In recent years, electrophotographic apparatuses that employ a contact charging method in which a voltage is applied to a charging member (contact charging member) disposed in contact with the electrophotographic photosensitive member to charge the electrophotographic photosensitive member have become widespread. In particular, a method of charging the electrophotographic photosensitive member by contacting a roller-shaped contact charging member (charging roller) with the surface of the electrophotographic photosensitive member and applying a voltage obtained by superimposing an alternating voltage on a direct current voltage (AC). / DC contact charging method) or a method of charging an electrophotographic photosensitive member by applying a voltage of only a direct current voltage (DC contact charging method) has become mainstream.

  In the case of the AC / DC contact charging method, a direct current power supply and an alternating current power supply are required, which increases the cost of the electrophotographic apparatus itself, and increases the size of the electrophotographic apparatus compared to the case where only a direct current voltage is used. There is a demerit such that the durability of the contact charging member and the electrophotographic photosensitive member is reduced by consuming a large amount of current. Therefore, it can be said that the DC contact charging method is more preferable in view of cost reduction, miniaturization, and high durability of the electrophotographic apparatus.

  However, the electrophotographic apparatus adopting the DC contact charging method is inferior in the uniformity of the surface potential of the electrophotographic photosensitive member (charging uniformity) at the time of charging as compared with the electrophotographic apparatus adopting the AC / DC contact charging method. For this reason, a stripe-like defective image (hereinafter also referred to as “charging streak”) in a direction (hereinafter referred to as “longitudinal direction”) perpendicular to the circumferential direction of the electrophotographic photosensitive member due to uneven charging in a halftone image or the like tends to be a problem.

  With respect to this problem, proposals for improvement have been made from the surface of the charging member, and as a method for improving the uniformity, uniform resistance distribution and improved surface properties are being studied. For example, with respect to the former, each layer constituting the contact charging member using a resin having a relatively low volume resistivity as a binding material for the contact charging member surface layer, which improves the dispersion of the conductive substance in the contact charging member surface layer. A measure such as uniformly adjusting the film thickness of the film is mentioned. As for the latter, there are measures such as adding a leveling agent to the surface layer of the contact charging member and improving the surface property of the elastic layer of the contact charging member. Further, regarding surface properties, a proposal is made that uniform chargeability can be obtained even when a charged object is charged by applying only a direct current voltage by setting the surface roughness of the outermost layer of the contact charging member to 5 μm or less (patent) Reference 1) and the surface roughness of the contact charging member is set to 20 μm or less with a 10-point average surface roughness Rzjis measured according to JIS standard B-0601. Is proposed (see Patent Document 2).

  Although the above-mentioned proposal has almost improved initial charge uniformity, stabilization of charge uniformity (deteriorating substances such as developer and paper dust adhere to the surface of the contact charging member with long-term use. In particular, partial adhesion unevenness and a large amount of adhesion may occur, which may cause a decrease in charging uniformity.)

  In order to solve the problem of stabilization of the charging uniformity in the long-term use, there has been a proposal to improve the charging member by adjusting the surface roughness of the charging member. For example, a technique for ensuring charging uniformity by controlling the surface roughness of the charging member (see Patent Documents 3 and 4), and charging uniformity by controlling the surface roughness of the charging member and the photosensitive member surface friction coefficient. There is a technology to secure (see Patent Document 5).

  In recent years, a method for appropriately roughening the surface of the electrophotographic photosensitive member has been proposed for the purpose of improving the performance of cleaning the surface of the photosensitive member with a cleaning member.

  As a technique for roughening the surface of the electrophotographic photosensitive member, Patent Document 6 discloses that the surface roughness (circumference) of the electrophotographic photosensitive member is easy to separate the transfer material from the surface of the electrophotographic photosensitive member. A technique for keeping the roughness of the surface within a specified range is disclosed. Patent Document 6 discloses a method of roughening the surface of an electrophotographic photosensitive member into a crusty skin by controlling the drying conditions when forming the surface layer.

  Patent Document 7 discloses a technique for roughening the surface of an electrophotographic photosensitive member by containing particles in a surface layer.

  Patent Document 8 discloses a technique for roughening the surface of the electrophotographic photosensitive member by polishing the surface of the surface layer using a metal wire brush.

  Patent Document 9 discloses a technique for roughening the surface of an organic electrophotographic photoreceptor using specific cleaning means and toner. According to this document, it is described that the cleaning blade curling and the edge chipping, which are problems when used in an electrophotographic apparatus having a specific process speed or higher, are solved.

  Patent Document 10 discloses a technique for roughening the surface of an electrophotographic photosensitive member by polishing the surface of a surface layer using a film-like abrasive.

  Patent Document 11 discloses a technique for roughening the peripheral surface of an electrophotographic photosensitive member by blasting. However, details of the surface shape of the electrophotographic photosensitive member roughened by the method as described above are unknown.

  Patent Document 12 discloses a technique for roughening the peripheral surface of the electrophotographic photosensitive member by the blasting process, and discloses an electrophotographic photosensitive member having a predetermined dimple shape, which is easily generated under high temperature and high humidity. It is described that improvements are made in terms of flow and toner transferability.

Patent Document 13 discloses a technique for compression molding the surface of an electrophotographic photosensitive member using a well-shaped uneven stamper.
JP-A-5-341620 JP-A-8-286468 JP 2004-061640 A JP 2004-309911 A JP 2004-038056 A JP-A-53-92133 JP-A-52-26226 JP-A-57-94772 JP-A-1-99060 Japanese Patent Laid-Open No. 2-139666 JP-A-2-150850 International Publication No. 2005/93518 Pamphlet JP 2001-0666814 A

  Generally, it is known that the smaller the surface roughness of the charging member, the more the fouling substances can be prevented from adhering to the surface of the charging member due to long-term use. On the other hand, if the surface roughness is too large, an image defect such as a spot may occur due to a charging defect caused by the surface shape of the charging member. From these viewpoints, it is preferable that the charging member has a smaller surface roughness.

  Further, by using the proposals shown in Patent Document 3 to Patent Document 5, it is possible to achieve stabilization of charging uniformity in long-term use, but the production of the charging roller becomes complicated. Therefore, when considering the simplification of the charging roller, it can be said that it is still desired to stabilize the charging uniformity in long-term use even when the charging member is charged with a small surface roughness.

  In the proposals shown in Patent Document 6 to Patent Document 12, the cleaning property is improved by processing the surface of the electrophotographic photosensitive member. However, when the surface is charged by a charging member having a small surface roughness, it is used for a long time. It is not sufficient to achieve stabilization of charging uniformity in

  In addition, in the electrophotographic photoreceptor disclosed in Patent Document 13, toner transferability is improved by providing fine irregularities on the surface of the photoreceptor, but it is charged by a charging member having a small surface roughness. In some cases, it is not sufficient to achieve stabilization of charging uniformity in long-term use.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a process cartridge and an electrophotographic apparatus that realize stabilization of charging uniformity in long-term use when charged by a charging member having a small surface roughness.

  As a result of intensive studies, the inventors have arranged long concave portions on the surface of the electrophotographic photosensitive member so as to satisfy certain conditions, so that they can be used for a long time when charged by a charging member having a small surface roughness. It has been found that stabilization of charging uniformity can be effectively realized, and the present invention has been made.

That is, according to the present invention comprises an electrophotographic photosensitive member having a photosensitive layer provided on a support and the support, and a contact charging member is smaller than the ten-point average roughness Rzjis of the surface 5.0 .mu.m, electronic In the process cartridge that is detachable from the photographic device body ,
The electrophotographic photosensitive member, the surface for forming an electrostatic latent image, comprising a plurality of each independent depressed portions,
Each of the concave portions, the long axis diameter of the surface openings (Rpc) is minor axis diameter of the surface openings I der below 10 [mu] m (Lpc) is the deepest and the open I der than 1.0μm A concave portion having a distance (Rdv) to the hole surface of 0.3 μm or more;
Each of the concave-shaped portion, at 4 99 straight lines you perpendicular to the photosensitive member rotation direction for the region of the square parallel one side 100μm to an edge of the photosensitive member rotation direction at the surface of the electrophotographic photosensitive member 500 to overlap with so that the 400 or more present is concave shaped portion of the 499 straight lines when equal parts, and wherein <br/> being disposed on the entire surface of the electrophotographic photosensitive member A process cartridge is provided.

Further, according to the present invention, the support and the electrophotographic photosensitive member to have a photosensitive layer provided on the support, the electrophotographic photosensitive average roughness Rzjis ten-point of the surface with a small contact charging member than 5.0μm Charging means for contact charging the surface of the body, exposure means for exposing the charged electrophotographic photosensitive member to form an electrostatic latent image on the surface of the electrophotographic photosensitive member, and the surface of the electrophotographic photosensitive member Developing means for developing the electrostatic latent image formed on the surface of the electrophotographic photosensitive member with toner, and transferring the toner image formed on the surface of the electrophotographic photosensitive member onto a transfer material An electrophotographic apparatus comprising transfer means for
The electrophotographic photosensitive member has a plurality of independent concave portions on the surface for forming an electrostatic latent image,
Each of the concave portions, the long axis diameter of the surface openings (Rpc) is minor axis diameter of the surface openings I der below 10 [mu] m (Lpc) is the deepest and the open I der than 1.0μm A concave portion having a distance (Rdv) to the hole surface of 0.3 μm or more;
Each of the concave-shaped portion, at 4 99 straight lines you perpendicular to the photosensitive member rotation direction for the region of the square parallel one side 100μm to an edge of the photosensitive member rotation direction at the surface of the electrophotographic photosensitive member 500 to overlap with so that the 400 or more present is concave shaped portion of the 499 straight lines when equal parts, and wherein <br/> being disposed on the entire surface of the electrophotographic photosensitive member An electrophotographic apparatus is provided.

  According to the present invention, it is possible to provide a process cartridge and an electrophotographic apparatus capable of stabilizing the charging uniformity in long-term use even when charged by a charging member having a small surface roughness.

  Hereinafter, the present invention will be described in more detail.

As described above, the present invention provides a process cartridge that includes at least an electrophotographic photosensitive member and a contact charging member and is detachable from the electrophotographic apparatus main body.
The electrophotographic photosensitive member has a support and a photosensitive layer provided on the support, and has a plurality of independent concave portions on the surface, and a major axis diameter of a surface opening portion of each concave portion. (Rpc) is 10 μm or less, the minor axis diameter (Lpc) is 1.0 μm or more, and the distance (Rdv) between the deepest part of each concave-shaped part and the aperture surface is 0.3 μm or more,
Each side of the electrophotographic photosensitive member is divided into four equal parts in the rotational direction of the photosensitive member and divided into 25 equal parts in the direction perpendicular to the rotational direction of the photosensitive member, and one side is in each of the regions A. When a square region B having a side of 100 μm parallel to the electrophotographic photosensitive member rotation direction is provided, and each region B is divided into 500 equal parts by 499 straight lines orthogonal to the photosensitive member rotation direction, In each, 400 or more of 499 overlap with the concave shape part,
The process cartridge is characterized in that the surface of the charging member has a ten-point average roughness Rzjis of less than 5 μm.

  The independent concave shape portion in the present invention indicates a state where each concave shape portion is clearly separated from other concave shape portions. The concave portion formed on the surface of the electrophotographic photosensitive member in the present invention is, for example, a shape constituted by a straight line, a shape constituted by a curve, or a shape constituted by a straight line and a curve in the observation of the surface of the photosensitive member. Is mentioned. Examples of the shape constituted by straight lines include a triangle, a quadrangle, a pentagon, and a hexagon. Examples of the shape constituted by the curve include a circular shape or an elliptical shape. Examples of the shape constituted by straight lines and curves include a square with a rounded corner, a hexagon with a rounded corner, and a sector. In addition, the concave portion on the surface of the electrophotographic photosensitive member in the present invention includes, for example, a shape constituted by a straight line, a shape constituted by a curve, or a shape constituted by a straight line and a curve in observation of the cross section of the photosensitive member. It is done. Examples of the shape constituted by straight lines include a triangle, a quadrangle, and a pentagon. Examples of the shape constituted by the curve include a partial circular shape and a partial elliptical shape. Examples of the shape constituted by straight lines and curves include a square with a rounded corner or a fan shape. Specific examples of the concave portion on the surface of the electrophotographic photosensitive member in the present invention include the concave portion shown in FIGS. In the present invention, the concave portions on the surface of the electrophotographic photosensitive member may have different shapes, sizes or depths, and all the concave portions have the same shape, size or depth. May be. Further, the surface of the electrophotographic photosensitive member may be a surface in which concave portions having different shapes, sizes or depths and concave portions having the same shape, size or depth are combined. Good.

  The major axis diameter in the present invention indicates the length of the maximum straight line among the straight lines crossing the apertures of each concave shaped part. Specifically, as shown by the major axis diameter (Rpc) in FIG. 1 and the major axis diameter (Rpc) in FIG. 3, the surface around the opening of the concave portion in the electrophotographic photoreceptor is shown. The reference length indicates the length when the distance between the two straight lines is maximized when the concave portion is sandwiched between two parallel straight lines in contact with the end of the aperture. For example, when the surface shape of the concave portion is a circle, the diameter is indicated. When the surface shape is an ellipse, the major axis is indicated. When the surface shape is a quadrangle, a long diagonal line among the diagonal lines is indicated.

  The minor axis diameter in the present invention indicates the length of the minimum straight line among the straight lines crossing the apertures of the concave portions. Specifically, as indicated by the short axis diameter (Lpc) in FIG. 2, the surface around the opening of the concave portion in the electrophotographic photosensitive member is used as a reference and contacts the end of the opening. The length when the distance between the two straight lines is minimized when the concave portion is sandwiched between two parallel straight lines is shown. For example, when the surface shape of the concave portion is a circle, the diameter is indicated, and when the surface shape is an ellipse, the minor axis is indicated.

  As shown in FIG. 3, the distance (Rdv) between the deepest portion of the concave portion and the aperture surface in the present invention is based on the surface around the aperture portion of the concave portion in the electrophotographic photosensitive member. The distance between the deepest part of the concave shape part and the aperture surface is shown.

  In order to influence the formation of the latent image generated on the surface of the electrophotographic photosensitive member, the concave portion is formed at least on the surface of the electrophotographic photosensitive member.

  The concave portion is formed by dividing the surface of the electrophotographic photosensitive member into four equal parts in the rotational direction of the photosensitive member and dividing the surface into 25 equal parts in a direction perpendicular to the rotational direction of the photosensitive member. When a square region B having a side of 100 μm and having one side parallel to the rotation direction of the photoconductor is provided, and each region B is divided into 500 equal parts by 499 straight lines orthogonal to the photoconductor rotation direction. In each of the regions B, there are concave portions so as to overlap 400 or more of the 499 straight lines.

  The method of taking the area A will be described with reference to FIGS. FIG. 5 shows the surface 2 of the electrophotographic photoreceptor shown in FIG. 4 cut and developed by a straight line OP extending in the direction perpendicular to the rotation direction of the photoreceptor on the surface. Point O ′ and point P ′ in FIG. 5 are points that overlap with point O and point P in FIG. 4 before development, respectively. The rectangular OPP'O 'in FIG. 5 is divided into 4 equal parts in the photoconductor rotation direction and 25 equal parts in the direction orthogonal to the photoconductor rotation direction, so that a total of 100 regions A are taken as shown in FIG. (In FIG. 5, a part of the region A is omitted).

The region B Thus provided in the resulting area A which is shown in FIG. 6 what the straight line L ₁ perpendicular to the photosensitive member rotation direction was 500 equal parts in total 499 pieces of L _499. As indicated by the arrows in FIG. 6, the interval between the straight lines is 0.2 μm.

  The overlapping of the concave portion and the straight line in the region B will be described with reference to FIG. Specifically, the fact that the straight line in the region B and the concave portion 3 in the present invention overlap each other is a state shown by (7-a), (7-b) and (7-c) in FIG. Indicates. On the contrary, the state in which the straight line in the region B and the concave portion do not overlap each other specifically indicates a state indicated by (7-d) in FIG. In the present invention, when the straight line in the region B overlaps at least a part of one or more of the concave-shaped portions, the straight line is counted as a straight line overlapping the concave-shaped portions.

  In the electrophotographic photosensitive member that satisfies the above conditions, image defects such as charging stripes that are likely to occur when a charging roller having a small surface roughness is effectively used on the entire surface can be suppressed.

  In recent years, from the viewpoints of cost reduction, miniaturization, and high durability of an electrophotographic apparatus, an electrophotographic apparatus adopting a DC contact charging method is often used. In the DC contact charging method, the charging streak phenomenon is likely to be a problem, but in particular, when the 10-point average roughness Rzjis on the surface of the charging roller is smaller than 5 μm, there is a tendency.

  In the present invention, a method for suppressing the charging streaking phenomenon by having a specific concave-shaped portion on the surface of the electrophotographic photosensitive member is shown. As the mechanism, the following is presumed, and FIG. Will be described.

  It is thought that image defects called charged streaks occur when latent image potential unevenness that occurs during charging is recognized as streaky density unevenness parallel to the longitudinal direction when developed to an intermediate color such as a halftone. It is done. Therefore, it can be estimated that the latent image potential unevenness occurring at that time is a straight line substantially parallel to the longitudinal direction. Then, in the latent image potential unevenness, it is indicated by a boundary (8-c in FIG. 8) between a place where the charged potential is high (8-a in FIG. 8) and a relatively low place (8-b in FIG. 8). , Called edges) are arranged on a straight line substantially parallel to the longitudinal direction as shown in FIG.

  The electrophotographic photosensitive member according to the present invention has a major axis diameter (Rpc) of 10 μm or less, a minor axis diameter (Lpc) of 1.0 μm or more on the surface of the electrophotographic photosensitive member, and a deepest portion and an aperture surface. And a plurality of independent concave portions having a distance (Rdv) of 0.3 μm or more. The concave shape portion is expected to have different chargeability compared to the non-concave shape portion due to the difference in the surface layer film thickness. Accordingly, by having the concave portion, the edge of the linear latent image potential unevenness substantially parallel to the longitudinal direction generated on the surface of the electrophotographic photosensitive member is cut off. A concave portion that cuts off the edge of the latent image potential unevenness is indicated by 8-d in FIG. Concave portions where the edges of the latent image potential unevenness are not cut off are indicated by 8-e and 8-f in the figure. As a result, it is considered that the effect of the present invention is obtained because the contrast of the developed charged streaks is lowered and it is difficult to recognize the streaky density unevenness.

  Furthermore, the electrophotographic photosensitive member of the present invention is divided into four equal parts in the rotational direction of the photosensitive member and divided into 25 equal parts in the direction orthogonal to the rotational direction of the photosensitive member. A square region B having a side of 100 μm and having a side parallel to the photoconductor rotation direction is provided. Then, when each of the regions B is divided into 500 equal parts by 499 straight lines orthogonal to the photoconductor rotation direction, in each of the regions B, 400 or more of the 499 straight lines are the concave portion. Is an electrophotographic photosensitive member overlapping with A photoreceptor satisfying this condition is an electrophotographic photoreceptor in which the edge of a linear latent image potential unevenness substantially parallel to the longitudinal direction is cut across the entire surface of the photoreceptor. Therefore, even when linear latent image potential unevenness substantially parallel to the longitudinal direction is generated, the edge of the edge is cut to reduce the contrast of the developed charged stripe, and the uneven density on the stripe is recognized. hard.

  The major axis diameter (Rpc) of the concave portion in the present invention is 10 μm or less, preferably 1.5 μm or more, and preferably 9.0 μm or less. More preferably, it is 5.0 μm or less.

  Moreover, although the short axis diameter (Lpc) of the concave shaped part in the present invention is 1.0 μm or more, it is preferably 1.5 μm or more and 9.0 μm or less. More preferably, it is 2.0 μm or more. In the present invention, a long and thin concave portion having a large major axis diameter (Rpc) and a minor axis diameter (Lpc) is not preferable because the edge of the latent image potential unevenness may be nonuniform.

  Further, the distance (Rdv) between the deepest portion of the concave portion and the aperture surface in the present invention is 0.3 μm or more, but preferably 0.5 μm or more and 10.0 μm or less. More preferably, it is 5.0 μm or less. If it is smaller than 0.3 μm, sufficient effects may not be exhibited through durability. If it is larger than 10.0 μm, there is a concern about deterioration of the photosensitive characteristics due to local discharge.

  Moreover, it is preferable that the value (Rdv / Rpc) of the ratio of the distance (Rdv) between the deepest portion and the aperture surface to the major axis diameter (Rpc) of the concave portion in the present invention is 0.1 or more. A direction smaller than 0.1 is not preferable because it is a direction in which the effect of lowering the contrast of the charging stripe due to the breakage of the edge of the latent image potential unevenness is lost.

  In addition, in the concave portion in the present invention, in each of the regions B, 450 or more of the 499 straight lines overlap with the concave portion in order to enhance the effect of suppressing the charging stripe. preferable.

  In the present invention, the concave portion on the surface of the electrophotographic photosensitive member can be measured using, for example, a commercially available laser microscope, optical microscope, electron microscope, or atomic force microscope.

  As the laser microscope, for example, the following devices can be used. Ultra-deep shape measurement microscope VK-8550, ultra-deep shape measurement microscope VK-9000 and ultra-deep shape measurement microscope VK-9500 (all manufactured by Keyence Corporation): Surface shape measurement system Surface Explorer SX-520DR type machine (( Ryoka System Co., Ltd.): Scanning confocal laser microscope OLS3000 (Olympus Co., Ltd.): Real color confocal microscope Oplitex C130 (Lasertec Co., Ltd.).

  As the optical microscope, for example, the following devices can be used. Digital microscope VHX-500 and digital microscope VHX-200 (both manufactured by Keyence Corporation): 3D digital microscope VC-7700 (manufactured by OMRON Corporation).

  As the electron microscope, for example, the following devices can be used. 3D Real Surface View Microscope VE-9800 and 3D Real Surface View Microscope VE-8800 (both manufactured by Keyence Corporation): Scanning Electron Microscope Conventional / Variable Pressure SEM (manufactured by SII Nano Technology Co., Ltd.): Scanning electron microscope SUPERSCAN SS-550 (manufactured by Shimadzu Corporation).

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

  Using the microscope, the major axis diameter (Rpc), minor axis diameter (Lpc) and the distance (Rdv) between the deepest part and the aperture surface of the concave part in the measurement field can be measured with a predetermined magnification. I can do it.

  In addition, about the concave shape part whose major axis diameter is about 1 μm or less, it is possible to observe with a laser microscope and an optical microscope, but in order to further improve the measurement accuracy, observation and measurement with an electron microscope are used in combination. It is preferable to do.

Next, a method for forming the surface of the electrophotographic photosensitive member according to the present invention will be described. The method for forming the surface shape is not particularly limited as long as it is a method capable of satisfying the requirements related to the concave portion. If an example of the method for forming the electrophotographic photoreceptor surface is given,
(1) A method for forming the surface of an electrophotographic photosensitive member by laser irradiation having an output characteristic having a pulse width of 100 ns (nanoseconds) or less,
(2) A surface forming method for transferring a shape by pressing a mold having a predetermined shape against the surface of the electrophotographic photosensitive member;
(3) A method for forming a surface in which the surface is dewed when the surface layer of the electrophotographic photosensitive member is formed,
Is mentioned.

  A method for forming the surface of an electrophotographic photosensitive member by laser irradiation having an output characteristic with a pulse width of 100 ns (nanoseconds) or less will be described. Specific examples of the laser used in this method include an excimer laser using a gas such as ArF, KrF, XeF or XeCl as a laser medium, and a femtosecond laser using titanium sapphire as a medium. Furthermore, the wavelength of the laser light in the laser irradiation is preferably 1,000 nm or less.

  The excimer laser is a laser beam emitted in the following steps. First, energy is applied to a mixed gas of a rare gas such as Ar, Kr or Xe and a halogen gas such as F or Cl by, for example, discharge, electron beam and X-ray to excite the above elements. Combine. Thereafter, excimer laser light is emitted when dissociating by falling to the ground state. Examples of the gas used in the excimer laser include ArF, KrF, XeCl, and XeF, and any of them may be used. In particular, KrF or ArF is preferable.

As a method for forming the concave portion, a mask in which the laser light shielding portion 4 and the laser light transmitting portion 5 shown in FIG. 9 are appropriately arranged is used. Only the laser beam that has passed through the mask is condensed by the lens and irradiated on the surface of the electrophotographic photosensitive member, thereby forming a concave portion having a desired shape and arrangement. In the above method for forming the surface of an electrophotographic photosensitive member by laser irradiation, a large number of concave portions within a certain area can be processed instantaneously and simultaneously regardless of the shape or area of the concave portion. It takes a short time. An area of several mm ² to several cm ^{2 on} the surface of the electrophotographic photosensitive member is processed per irradiation by laser irradiation using a mask. In laser processing, as shown in FIG. 10, first, the electrophotographic photosensitive member 9 is rotated by the workpiece rotating motor 7. While rotating, the workpiece moving device 8 shifts the laser irradiation position 6 in the axial direction of the electrophotographic photosensitive member, whereby a concave portion can be efficiently formed over the entire surface of the electrophotographic photosensitive member 9. .

  The major axis diameter (Rpc) is 10 μm or less, the minor axis diameter (Lpc) is 1.0 μm or more, and the deepest portion and the aperture surface are formed by the above-described method of forming the surface of the electrophotographic photosensitive member by laser irradiation. A plurality of independent concave portions having a distance (Rdv) of 0.3 μm or more, and the surface of the electrophotographic photosensitive member is divided into four equal parts in the rotational direction of the photosensitive member in a direction perpendicular to the rotational direction of the photosensitive member. In each of 100 regions A obtained by dividing into 25 equal parts, a square region B having a side of 100 μm and having a side parallel to the rotation direction of the photosensitive member is provided. When divided into 500 equal parts by 499 straight lines orthogonal to the rotation direction of the photoconductor, an electrophotographic photoconductor is produced in which 400 or more of the 499 overlap each of the concave portions in each region B. be able to.

  When the surface of the electrophotographic photosensitive member is formed by laser irradiation, the distance between the deepest portion and the aperture surface can be controlled by adjusting manufacturing conditions such as the laser irradiation time and the number of times. From the viewpoint of manufacturing accuracy or productivity, when forming the surface of an electrophotographic photosensitive member by laser irradiation, the distance between the deepest portion of the concave-shaped portion and the aperture surface by one irradiation is 0.1 μm or more. And preferably 2.0 μm or less, more preferably 0.3 μm or more, and 1.2 μm or less. FIG. 11 shows an example of a concave portion that can be formed on the surface of the electrophotographic photosensitive member by the above method. By using the method of forming the surface of the electrophotographic photosensitive member by laser irradiation, the surface processing of the electrophotographic photosensitive member with high precision and high flexibility can be realized with high controllability of the size, shape and arrangement of the concave portions. .

  Next, a method for forming a surface for transferring a shape by pressing a mold having a predetermined shape against the surface of the electrophotographic photoreceptor will be described.

  FIG. 12 is a diagram showing an example of a schematic diagram of a pressure contact shape transfer processing apparatus using a mold in the present invention. After the predetermined mold 13 is attached to the pressure device 12 that can repeatedly press and release, the mold is brought into contact with the photoconductor 14 with a predetermined pressure to transfer the shape. Thereafter, the pressurization is once released and the photosensitive member 14 is rotated, and then the pressurization and the shape transfer process are performed again. By repeating this process, it is possible to form a predetermined concave-shaped portion over the entire circumference of the photoreceptor.

  For example, as shown in FIG. 13, after a mold 13 having a predetermined shape about the entire circumference of the photoconductor 14 is attached to the pressure device 12, a predetermined pressure is applied to the photoconductor 14. The predetermined concave shape may be formed over the entire circumference of the photoconductor by rotating and moving the photoconductor.

  It is also possible to sandwich the sheet-shaped mold between the roll-shaped pressurizing device and the photoreceptor, and to perform surface processing while feeding the mold sheet.

  Further, the mold or the photoreceptor may be heated for the purpose of efficiently transferring the shape. The heating temperature of the mold and the photoreceptor is arbitrary as long as the shape of the present invention can be formed, but the mold temperature (° C.) during shape transfer is higher than the glass transition temperature (° C.) of the photosensitive layer on the support. It is preferable to be heated. Further, in addition to the heating of the mold, the concave shape portion transferred to the surface of the photosensitive member is controlled such that the temperature (° C.) of the support during shape transfer is controlled to be lower than the glass transition temperature (° C.) of the photosensitive layer. Is preferable for stably forming.

  The material, size, and shape of the mold itself can be selected as appropriate. Examples of the material include a finely patterned metal and a silicon wafer surface patterned with a resist, a resin film in which fine particles are dispersed, and a metal film coated on a resin film having a predetermined fine surface shape. An example of the mold shape is shown in FIG. 14 (partially enlarged view of the photoreceptor contact surface) and FIG. 15 (partially enlarged view of the photoreceptor contact surface section).

  Further, an elastic body may be provided between the mold and the pressure device for the purpose of imparting pressure uniformity to the photoreceptor.

  The major axis diameter (Rpc) is 10 μm or less and the minor axis diameter (Lpc) is 1.0 μm by the above-described surface forming method in which a mold having a predetermined shape is pressed against the surface of the electrophotographic photosensitive member to transfer the shape. There are a plurality of independent concave-shaped portions having a distance (Rdv) between the deepest portion and the aperture surface of 0.3 μm or more, and the surface of the electrophotographic photosensitive member is divided into four equal parts in the rotation direction of the photosensitive member. In each of a total of 100 regions A obtained by dividing into 25 equal parts in the direction orthogonal to the photoconductor rotation direction, each side is parallel to the photoconductor rotation direction and has a 100 μm side square shape. When a region B is provided and each region B is divided into 500 equal parts by 499 straight lines orthogonal to the photoconductor rotation direction, in each region B, 400 or more of the 499 regions have the concave shape. An electrophotographic photosensitive member that overlaps It is possible.

  In the case of forming a surface for performing shape transfer by pressing a mold having a predetermined shape against the surface of the electrophotographic photosensitive member, the distance between the deepest portion of the concave portion and the aperture surface is 0.1 μm or more and 10 μm. The following is preferable. By using a surface forming method in which a mold having a predetermined shape is pressed against the surface of the electrophotographic photosensitive member to transfer the shape, the control of the size, shape and arrangement of the concave portions is high, and the accuracy is high. High surface processing of an electrophotographic photosensitive member can be realized.

  Next, a method for forming a surface in which the surface has been condensed at the time of forming the surface layer of the electrophotographic photosensitive member will be described.

What is the method of forming a surface that has condensed on the surface layer formation of the electrophotographic photosensitive member?
(1) A surface layer containing a binder resin and a specific aromatic organic solvent, wherein the content of the aromatic organic solvent is 50% by mass to 80% by mass with respect to the total solvent mass in the surface layer coating solution. A coating process for preparing a coating liquid for coating and applying the coating liquid;
(2) A support holding step in which the support coated with the coating solution is held and the surface of the support coated with the coating solution is condensed.
(3) a drying step of drying the support by heating;
Shows a method for producing an electrophotographic photosensitive member, characterized in that a surface layer having independent concave portions formed on the surface is produced.

  Examples of the binder resin include acrylic resin, styrene resin, polyester resin, polycarbonate resin, polyarylate resin, polysulfone resin, polyphenylene oxide resin, epoxy resin, polyurethane resin, alkyd resin, and unsaturated resin. In particular, polymethyl methacrylate resin, polystyrene resin, styrene-acrylonitrile copolymer resin, polycarbonate resin, polyarylate resin or diallyl phthalate resin are preferable. Furthermore, a polycarbonate resin or a polyarylate resin is preferable. These can be used alone, as a mixture or as a copolymer, or one or more thereof.

  The specific aromatic organic solvent is a solvent having a low affinity for water. Specific examples include 1,2-dimethylbenzene, 1,3-dimethylbenzene, 1,4-dimethylbenzene, 1,3,5-trimethylbenzene and chlorobenzene.

  Although it is important that the surface layer coating solution contains an aromatic organic solvent, the surface layer coating solution further has an affinity for water for the purpose of stably producing a concave portion. A high organic solvent or water may be contained in the surface layer coating solution. As an organic solvent having high affinity with water, (methylsulfinyl) methane (common name: dimethyl sulfoxide), thiolane-1,1-dione (common name: sulfolane), N, N-dimethylcarboxamide, N, N -Preferred is diethyl carboxamide, dimethylacetamide or 1-methylpyrrolidin-2-one. These organic solvents may be contained alone or in combination of two or more.

  The above-mentioned support holding process in which the surface of the support is condensed indicates a process in which the support coated with the surface layer coating liquid is held for a certain period of time in an atmosphere in which the surface of the support is condensed. The dew condensation in this surface forming method means that droplets are formed on the support coated with the surface layer coating liquid by the action of water. The conditions for dew condensation on the surface of the support are affected by the relative humidity of the atmosphere holding the support and the volatilization conditions of the coating solution solvent (for example, heat of vaporization), but the aromatic organic solvent is completely contained in the surface layer coating solution. Since it is contained in an amount of 50% by mass or more based on the mass of the solvent, the influence of the volatilization condition of the coating solution solvent is small and mainly depends on the relative humidity of the atmosphere holding the support. The relative humidity at which the surface of the support is condensed is 40% or more and 100% or less. Further, the relative humidity is preferably 70% or more. In the support holding process, it is sufficient if there is a time required for forming droplets by condensation. From the viewpoint of productivity, it is preferably 1 second or longer and 300 seconds or shorter, and more preferably 10 seconds or longer and 180 seconds or shorter. Although relative humidity is important for the support holding step, the atmospheric temperature is preferably 20 ° C. or higher and 80 ° C. or lower.

  By the drying step of heating and drying, the droplets generated on the surface by the support holding step can be formed as concave portions on the surface of the photoreceptor. In order to form a concave portion with high uniformity, it is important to perform rapid drying, and thus heat drying is performed. It is preferable that the drying temperature in a drying process is 100 degreeC or more and 150 degrees C or less. The drying process time for drying by heating only needs to be a time for removing the solvent in the coating solution applied on the support and the water droplets formed by the condensation process. The drying process time is preferably 20 minutes or more and 120 minutes or less, and more preferably 40 minutes or more and 100 minutes or less.

  By the surface forming method in which the surface is condensed at the time of forming the surface layer of the electrophotographic photosensitive member, independent concave portions are formed on the surface of the photosensitive member. The method of forming the surface that has condensed the surface during the formation of the surface layer of the electrophotographic photosensitive member is that the droplets formed by the action of water are formed by using a solvent having a low affinity for water and a binder resin to form concave portions. It is a method of forming. Since the individual shapes of the concave portions formed on the surface of the electrophotographic photosensitive member produced by this manufacturing method are formed by the cohesive force of water, the concave portions are highly uniform. Since this manufacturing method is a manufacturing method that undergoes a step of removing droplets from a state in which the droplets or droplets are sufficiently grown, the concave portion on the surface of the electrophotographic photosensitive member is, for example, a droplet shape or a honeycomb. A concave portion having a shape (hexagonal shape) is formed. In the observation of the surface of the photoreceptor, the concave portion of the droplet shape is, for example, a concave portion that is observed in a circular shape or an elliptical shape. In the observation of the cross section of the photosensitive member, for example, a partial circular shape or a partial elliptical shape. The concave part observed is shown in FIG. In addition, the honeycomb-shaped (hexagonal) concave-shaped portion is a concave-shaped portion formed by, for example, close-packed droplets on the surface of the electrophotographic photosensitive member. Specifically, in the observation of the photoreceptor surface, for example, the concave portion is a circle, a hexagon or a hexagon with a round corner, and in the observation of the cross section of the photoreceptor, for example, a partial circle or a prism A concave-shaped part is shown.

  The major axis diameter (Rpc) is 10 μm or less, the minor axis diameter (Lpc) is 1.0 μm or more, and the deepest portion is formed by a method of forming a surface in which the surface is condensed at the time of forming the surface layer of the electrophotographic photosensitive member. There are a plurality of independent concave portions having a distance (Rdv) to the aperture surface of 0.3 μm or more, and the surface of the electrophotographic photosensitive member is divided into four equal parts in the rotational direction of the photosensitive member. In each of a total of 100 regions A obtained by equally dividing the cross section in 25 directions perpendicular to each other, a square region B having a side of 100 μm and having a side parallel to the rotation direction of the photosensitive member is provided. Are divided into 500 equal parts by 499 straight lines orthogonal to the rotation direction of the photosensitive member, and in each region B, 400 or more of the 499 pieces overlap with the concave portion. The body can be made. When the surface is formed by a method of dew condensation when forming the surface layer of the electrophotographic photosensitive member, the distance between the deepest part of each concave-shaped part and the aperture surface is 0.5 μm or more and 10 μm or less. It is preferable that the production conditions are as follows.

  The concave portion can be controlled by adjusting the manufacturing conditions within the range indicated by the manufacturing method. The concave portion can be controlled by, for example, the solvent type, the solvent content, the relative humidity in the support holding process, the holding time in the holding process, and the heating and drying temperature in the surface layer coating solution described in the present invention.

  Next, the configuration of the electrophotographic photoreceptor according to the present invention will be described.

  As described above, the electrophotographic photosensitive member according to the present invention includes a support and an organic photosensitive layer (hereinafter also simply referred to as “photosensitive layer”) provided on the support. As the electrophotographic photoreceptor according to the present invention, a cylindrical organic electrophotographic photoreceptor having a photosensitive layer formed on a cylindrical support is generally used, but a belt-like or sheet-like shape is also possible.

  Even if the photosensitive layer is a single-layer type photosensitive layer containing the charge transport material and the charge generation material in the same layer, the charge generation layer containing the charge generation material and the charge transport layer containing the charge transport material Separated layered (functionally separated type) photosensitive layers may be used. The electrophotographic photoreceptor according to the present invention is preferably a laminated photosensitive layer from the viewpoint of electrophotographic characteristics. In addition, even if the laminated type photosensitive layer is a normal type photosensitive layer in which the charge generation layer and the charge transport layer are laminated in this order from the support side, the reverse layer type photosensitive layer in which the charge transport layer and the charge generation layer are laminated in order from the support side. It may be a layer. In the electrophotographic photoreceptor according to the present invention, when a laminated type photosensitive layer is employed, a normal layer type photosensitive layer is preferable from the viewpoint of electrophotographic characteristics. Further, the charge generation layer may have a laminated structure, and the charge transport layer may have a laminated structure. Furthermore, it is possible to provide a protective layer on the photosensitive layer for the purpose of improving the durability.

  As a support body, what has electroconductivity (conductive support body) is preferable, for example, metal supports, such as aluminum, aluminum alloy, or stainless steel, can be used. In the case of aluminum or aluminum alloy, ED tube, EI tube, and these are cut, electrolytic composite polishing (electrolysis with electrode having electrolytic action and polishing with grinding stone having polishing action), wet or dry honing treatment Can also be used. In addition, the above metal support or resin support (polyethylene terephthalate, polybutylene terephthalate, phenol resin, polypropylene, or polystyrene resin) having a layer formed by vacuum deposition of aluminum, aluminum alloy, or indium oxide-tin oxide alloy. Can also be used. In addition, a support in which conductive particles such as carbon black, tin oxide particles, titanium oxide particles, or silver particles are impregnated in a resin or paper, or a plastic having a conductive binder resin can also be used.

  The surface of the support may be subjected to a cutting process, a roughening process, or an alumite process for the purpose of preventing interference fringes due to scattering of laser light.

When the volume resistivity of the support is a layer provided for imparting conductivity to the surface of the support, the volume resistivity of the layer is preferably 1 × 10 ¹⁰ Ω · cm or less, In particular, it is more preferably 1 × 10 ⁶ Ω · cm or less.

  Between the support and an intermediate layer or photosensitive layer (charge generation layer, charge transport layer) described later, there is a conductive layer for the purpose of preventing interference fringes due to scattering of laser light and covering scratches on the support. It may be provided. This is a layer formed by applying a coating liquid in which conductive powder is dispersed in an appropriate binder resin.

  Examples of such conductive powder include the following. Carbon black, acetylene black; metal powder such as aluminum, nickel, iron, nichrome, copper, zinc or silver; metal oxide powder such as conductive tin oxide or ITO.

  The binder resin used simultaneously is polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer. , Polyvinyl acetate, polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinylcarbazole, acrylic resin, silicone resin, epoxy resin, Examples thereof include thermoplastic resins such as melamine resin, urethane resin, phenol resin, and alkyd resin, thermosetting resin, and photocurable resin.

  The conductive layer consists of the conductive powder and the binder resin, an ether solvent such as tetrahydrofuran or ethylene glycol dimethyl ether; an alcohol solvent such as methanol; a ketone solvent such as methyl ethyl ketone; an aromatic carbon such as toluene. It can be formed by dispersing or dissolving in a hydrogen solvent and applying it. The average film thickness of the conductive layer is 0.2 μm or more, preferably 40 μm or more, more preferably 1 μm or more, and more preferably 35 μm or less, and further preferably 5 μm or more and 30 μm or less. It is even more preferable.

  The surface of a conductive layer in which a conductive pigment or a resistance adjusting pigment is dispersed tends to be roughened.

  An intermediate layer having a barrier function or an adhesive function may be provided between the support or the conductive layer and the photosensitive layer (charge generation layer, charge transport layer). The intermediate layer is formed, for example, for improving adhesion of the photosensitive layer, improving coating properties, improving charge injection from the support, and protecting the photosensitive layer from electrical breakdown.

  The intermediate layer can be formed by applying a curable resin and then curing to form a resin layer, or by applying an intermediate layer coating solution containing a binder resin on the conductive layer and drying.

  As the binder resin for the intermediate layer, water-soluble resins such as polyvinyl alcohol, polyvinyl methyl ether, polyacrylic acids, methyl cellulose, ethyl cellulose, polyglutamic acid or casein; polyamide resin, polyimide resin, polyamideimide resin, polyamic acid resin, melamine Examples thereof include resins, epoxy resins, polyurethane resins, and polyglutamic acid ester resins. In order to effectively develop the electrical barrier property, the binder resin of the intermediate layer is preferably a thermoplastic resin from the viewpoints of coatability, adhesion, solvent resistance and resistance. Specifically, a thermoplastic polyamide resin is preferable. The polyamide resin is preferably a low crystalline or non-crystalline copolymer nylon that can be applied in a solution state. The average film thickness of the intermediate layer is preferably 0.05 μm or more and 7 μm or less, more preferably 0.1 μm or more and 2 μm or less.

  In addition, in order to prevent the flow of electric charges (carriers) in the intermediate layer, semiconductive particles are dispersed in the intermediate layer, or an electron transport material (electron-accepting material such as an acceptor) is contained. You may let them.

  Next, the photosensitive layer in the present invention will be described.

  Examples of the charge generating material used in the electrophotographic photoreceptor according to the present invention include the following. Azo pigments such as monoazo, disazo or trisazo; phthalocyanine pigments such as metal phthalocyanine or non-metal phthalocyanine; indigo pigments such as indigo or thioindigo; perylene pigments such as perylene anhydride or perylene imide; anthraquinone or pyrenequinone Polycyclic quinone pigments such as: squarylium dyes, pyrylium salts or thiapyrylium salts, triphenylmethane dyes; inorganic substances such as selenium, selenium-tellurium or amorphous silicon; quinacridone pigments, azurenium salt pigments, cyanine dyes, xanthene dyes, quinoneimines Dye or styryl dye. These charge generation materials may be used alone or in combination of two or more. Among these, metal phthalocyanines such as oxytitanium phthalocyanine, hydroxygallium phthalocyanine or chlorogallium phthalocyanine are particularly preferable because of their high sensitivity.

  When the photosensitive layer is a laminated photosensitive layer, the binder resin used for the charge generation layer may be polycarbonate resin, polyester resin, polyarylate resin, butyral resin, polystyrene resin, polyvinyl acetal resin, diallyl phthalate resin, acrylic resin, methacrylic resin, Examples thereof include resins, vinyl acetate resins, phenol resins, silicone resins, polysulfone resins, styrene-butadiene copolymer resins, alkyd resins, epoxy resins, urea resins, and vinyl chloride-vinyl acetate copolymer resins. In particular, a butyral resin is preferred. These can be used alone, as a mixture or as a copolymer, or one or more thereof.

  The charge generation layer can be formed by applying and drying a charge generation layer coating solution obtained by dispersing a charge generation material together with a binder resin and a solvent. The charge generation layer may be a vapor generation film of a charge generation material. Examples of the dispersion method include a method using a homogenizer, an ultrasonic wave, a ball mill, a sand mill, an attritor, or a roll mill. The ratio between the charge generating material and the binder resin is preferably in the range of 10: 1 to 1:10, and more preferably in the range of 3: 1 to 1: 1.

  The solvent used for the charge generation layer coating solution is selected from the solubility and dispersion stability of the binder resin and charge generation material used. Examples of the organic solvent include alcohol solvents, sulfoxide solvents, ketone solvents, ether solvents, ester solvents, and aromatic hydrocarbon solvents.

  The average film thickness of the charge generation layer is preferably 5 μm or less, more preferably 0.1 μm or more and 2 μm or less.

  Further, various sensitizers, antioxidants, ultraviolet absorbers and / or plasticizers can be added to the charge generation layer as necessary. In order to prevent the flow of charges (carriers) in the charge generation layer from stagnation, the charge generation layer may contain an electron transport material (an electron accepting material such as an acceptor).

  Examples of the charge transport material used in the electrophotographic photoreceptor according to the present invention include triarylamine compounds, hydrazone compounds, styryl compounds, stilbene compounds, pyrazoline compounds, oxazole compounds, thiazole compounds, and triallylmethane compounds. These charge transport materials may be used alone or in combination of two or more.

  The charge transport layer can be formed by applying a charge transport layer coating solution obtained by dissolving a charge transport material and a binder resin in a solvent, and drying it. In addition, among the above charge transport materials, those having film formability alone can be formed as a charge transport layer by itself without using a binder resin.

  When the photosensitive layer is a laminated photosensitive layer, examples of the binder resin used for the charge transport layer include acrylic resin, styrene resin, polyester resin, polycarbonate resin, polyarylate resin, polysulfone resin, polyphenylene oxide resin, epoxy resin, Examples include polyurethane resins, alkyd resins, and unsaturated resins. In particular, polymethyl methacrylate resin, polystyrene resin, styrene-acrylonitrile copolymer resin, polycarbonate resin, polyarylate resin and diallyl phthalate resin are preferable. These can be used alone, as a mixture or as a copolymer, or one or more thereof.

  The charge transport layer can be formed by applying and drying a charge transport layer coating solution obtained by dissolving a charge transport material and a binder resin in a solvent. The ratio of the charge transport material and the binder resin is preferably in the range of 2: 1 to 1: 2 by mass ratio.

  The following are mentioned as a solvent used for the coating liquid for charge transport layers. Ketone solvents such as acetone or methyl ethyl ketone; ester solvents such as methyl acetate or ethyl acetate; ether solvents such as tetrahydrofuran, dioxolane, dimethoxymethane or dimethoxyethane; aromatic hydrocarbons such as toluene, xylene or chlorobenzene solvent. These solvents may be used alone or in combination of two or more. Among these solvents, it is preferable to use an ether solvent or an aromatic hydrocarbon solvent from the viewpoint of resin solubility.

  The average film thickness of the charge transport layer is preferably 5 μm or more and 50 μm or less, and more preferably 10 μm or more and 35 μm or less.

  In addition, for example, an antioxidant, an ultraviolet absorber, and / or a plasticizer can be added to the charge transport layer as necessary.

  In the present invention, in order to improve the durability, which is one of the characteristics required for the electrophotographic photosensitive member, the material design of the charge transport layer serving as the surface layer is important in the case of the functional separation type photosensitive member. For example, a method using a high-strength binder resin, a method for optimizing the ratio between a charge transporting material and a binder resin exhibiting plasticity, and a method using a polymer charge transporting material can be mentioned. In order to achieve this, it is effective to form the surface layer with a curable resin.

  Examples of the method for constituting the surface layer with a curable resin include, for example, constituting the charge transport layer with a curable resin, and also as a second charge transport layer or a protective layer on the charge transport layer. For example, a curable resin layer may be formed. The characteristics required for the curable resin layer are both the strength of the film and the charge transport capability, and it is generally composed of a charge transport material and a polymerized or crosslinkable monomer or oligomer.

  In the method of constituting these surface layers with a curable resin, a known hole transporting compound or electron transporting compound can be used as the charge transporting material. Examples of materials for synthesizing these compounds include chain polymerization materials having an acryloyloxy group or a styrene group. In addition, a material such as a sequential polymerization system having a hydroxyl group, an alkoxysilyl group or an isocyanate group can be used. In particular, a combination of a hole transporting compound and a chain polymerization material is preferable from the viewpoints of electrophotographic characteristics, versatility, material design, and production stability of an electrophotographic photoreceptor having a surface layer made of a curable resin. Furthermore, an electrophotographic photoreceptor constituted by a surface layer obtained by curing a compound having both a hole transporting group and an acryloyloxy group in the molecule is particularly preferable.

  As the curing means, known means such as heat, light or radiation (including electron beam) can be used. Of these, electron beam irradiation is preferred. The curing means may be used in combination, or may be cured by applying heat after electron beam irradiation.

  In the case of the charge transport layer, the average thickness of the cured layer is 5 μm or more and preferably 50 μm or less, more preferably 10 μm or more and 35 μm or less. In the case of the second charge transport layer or protective layer, it is preferably 0.1 μm or more and 20 μm or less, more preferably 1 μm or more and 10 μm or less.

  Various additives can be added to each layer of the electrophotographic photoreceptor according to the present invention. Examples of the additive include an antioxidant, a deterioration inhibitor for ultraviolet absorbers, and a lubricant for fluorine atom-containing resin particles.

  As described above, the electrophotographic photosensitive member according to the present invention has a specific concave portion at least on the surface of the electrophotographic photosensitive member. The concave shape portion of the present invention works effectively when applied to either a photoconductor having a high surface hardness or a photoconductor having a low surface hardness.

  Next, the charging member used in the present invention will be described. The charging member used in the present invention has a roller shape (hereinafter referred to as a charging roller), and the configuration thereof is, for example, a conductive support, an elastic layer formed on the outer periphery thereof, and further formed on the outer periphery thereof. Consists of a surface layer. Further, it is necessary to control the surface roughness of the charging roller within the following range.

  The ten-point average roughness (Rzjis) of the charging roller used in the present invention is 5.0 μm or less. In addition, the measurement of surface roughness measures the ten-point average surface roughness Rzjis using, for example, a surface roughness measuring instrument SE-3400 manufactured by Kosaka Laboratory. More specifically, Rzjis at arbitrary six points of the charging member is measured by the measuring device, and the average value of the six points is used as the ten-point average surface roughness.

  If the 10-point average surface roughness of the charging roller is much higher than the above range, the toner and toner external additives are likely to adhere to the surface of the charging roller due to continuous paper passing, and stains on the charging roller will occur on the image. easy.

  In addition, by controlling the surface of the charging roller to a roughness range within a specific range in this way, it is possible to suppress a difference in discharge charge amount due to a difference in height of the surface, and for example, a spot shape due to charging failure due to the surface shape of the charging member. Generation of image defects can be suppressed.

  Next, a process cartridge and an electrophotographic apparatus according to the present invention will be described. FIG. 16 is a diagram showing an example of a schematic configuration of an electrophotographic apparatus including a process cartridge having an electrophotographic photosensitive member according to the present invention.

  In FIG. 16, reference numeral 15 denotes a cylindrical electrophotographic photosensitive member, which is driven to rotate about a shaft 16 in a direction indicated by an arrow at a predetermined peripheral speed.

  The surface of the electrophotographic photosensitive member 15 that is driven to rotate is uniformly charged to a predetermined positive or negative potential by a charging unit (primary charging unit: for example, a charging roller) 17. Next, exposure light (image exposure light) 18 output from exposure means (not shown) such as slit exposure or laser beam scanning exposure is received. In this way, electrostatic latent images corresponding to the target image are sequentially formed on the surface of the electrophotographic photoreceptor 15.

  The electrostatic latent image formed on the surface of the electrophotographic photosensitive member is developed with toner contained in the developer of the developing means 19 to become a toner image. Next, the toner image formed and supported on the surface of the electrophotographic photoreceptor 15 is transferred from the transfer material supply means (not shown) to the electrophotographic photoreceptor 15 and the transfer means by the transfer bias from the transfer means (for example, transfer roller) 20. The image is sequentially transferred onto a transfer material fed in synchronization with the rotation of the electrophotographic photosensitive member 15 between 20 (contact portion).

  The transfer material (for example, paper) P that has received the transfer of the toner image is separated from the surface of the electrophotographic photosensitive member 15 and is introduced into the fixing means 22 to receive image fixing, thereby forming an image formed product (print, copy). Printed out.

  The surface of the electrophotographic photosensitive member 15 after the transfer of the toner image is cleaned by receiving a developer (toner) remaining after transfer by a cleaning means (for example, a cleaning blade) 21. Further, the surface of the electrophotographic photosensitive member 15 is subjected to charge removal processing by pre-exposure light (not shown) from pre-exposure means (not shown), and then repeatedly used for image formation. As shown in FIG. 16, when the charging unit 17 is a contact charging unit using, for example, a charging roller, pre-exposure is not always necessary.

  Among the components of the electrophotographic photosensitive member 15, the charging unit 17, the developing unit 19, and the cleaning unit 21, a plurality of components may be housed in a container and integrally combined as a process cartridge. The process cartridge may be configured to be detachable from an electrophotographic apparatus main body such as a copying machine or a laser beam printer. In FIG. 16, the electrophotographic photosensitive member 15, the charging unit 17, the developing unit 19, and the cleaning unit 21 are integrally supported to form a cartridge, and the electrophotographic apparatus is used for the electrophotography using a guide unit 24 such as a rail of the electrophotographic apparatus main body. The process cartridge 23 is detachable from the apparatus main body.

  Hereinafter, the present invention will be described in more detail with reference to specific examples. In the examples, “part” means “part by mass”.

Example 1
<Production of electrophotographic photoreceptor>
An aluminum cylinder (JIS-A3003, aluminum alloy) having a length of 257 mm and a diameter of 24 mm manufactured by the extrusion / pulling-out process was used as a support (cylindrical support).

Next, 60 parts of powder composed of barium sulfate particles having a coating layer of the following component tin oxide (trade name: Pastoran PC1, manufactured by Mitsui Mining & Smelting Co., Ltd.)
Titanium oxide (trade name: TITANIX JR, manufactured by Teika Co., Ltd.) 15 parts phenol resin 43 parts (trade name: Priorofen J-325, manufactured by Dainippon Ink & Chemicals, Inc., resin solid content 60%)
0.015 parts of silicone oil (trade name: SH28PA, manufactured by Toray Dow Corning Co., Ltd.)
3.6 parts of silicone resin particles (trade name: Tospearl 120, manufactured by GE Toshiba Silicone Co., Ltd.)
A solution composed of 50 parts of 1-methoxy-2-propanol and 50 parts of methanol was dispersed with a ball mill for about 20 hours to prepare a coating material for a conductive layer. This conductive layer coating material is applied on the support by the dipping method and cured by heating in an oven heated to 140 ° C. for 1 hour, whereby the average film thickness at a position 130 mm from the upper end of the support is 15 μm. A conductive layer was formed.

  Next, 10 parts of copolymer nylon resin (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.), 30 parts of N-methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Teikoku Chemical Industry Co., Ltd.) A coating solution for intermediate layer in which 400 parts of methanol is dissolved in 200 parts of n-butanol is dip-coated on the conductive layer and heated and dried in an oven heated to 100 ° C. for 30 minutes. An intermediate layer having an average film thickness of 0.45 μm at a position of 130 mm from the upper end of the support was formed.

  Next, in the CuKα characteristic X-ray diffraction, the Bragg angles (2θ ± 0.2 °) are 7.5 °, 9.9 °, 16.3 °, 18.6 °, 25.1 ° and 28.3 °. 20 parts of a crystalline form of hydroxygallium phthalocyanine having a strong peak, 0.2 part of a calixarene compound represented by the following structural formula (1),

10 parts of polyvinyl butyral (trade name: ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.) and 600 parts of cyclohexanone were dispersed in a sand mill apparatus using glass beads having a diameter of 1 mm for 4 hours, and then 700 parts of ethyl acetate was added. A charge generation layer coating was prepared. The charge generation layer coating material is applied onto the intermediate layer by a dip coating method, and heated and dried in an oven heated to 80 ° C. for 15 minutes, whereby the average film thickness at a position of 130 mm from the upper end of the support is 0.17 μm. The charge generation layer was formed.

  Next, 70 parts of a charge transport material (hole transport material) represented by the following structural formula (2)

  Polycarbonate resin composed of repeating units represented by the following structural formula (3) (Iupilon Z-400, manufactured by Mitsubishi Engineering Plastics) [viscosity average molecular weight (Mv) 40,000] 100 parts

Was dissolved in a mixed solvent of 600 parts of chlorobenzene and 200 parts of methylal to prepare a coating material for a charge transport layer. Using this, the charge transport layer is dip-coated on the charge generation layer, and is heated and dried in an oven heated to 100 ° C. for 30 minutes, whereby the average film thickness at a position of 130 mm from the upper end of the support is 15 μm. A charge transport layer was formed.

Subsequently, 0.5 part of fluorine atom-containing resin (trade name: GF-300, manufactured by Toagosei Co., Ltd.) was added to 1,1,2,2,3,3,4-heptafluorocyclopentane (trade name: It was dissolved in a mixed solvent of 20 parts of ZEOLORA H, manufactured by Nippon Zeon Co., Ltd. and 20 parts of 1-propanol. 10 parts of tetrafluoroethylene resin powder (trade name: Lubron L-2, manufactured by Daikin Industries, Ltd.) was added to the solution in which the fluorine atom-containing resin was dissolved. Thereafter, the solution to which the tetrafluoroethylene resin powder was added was subjected to treatment four times at a pressure of 600 kgf / cm ² with a high-pressure disperser (trade name: Microfluidizer M-110EH, manufactured by Microfluidics, USA) Dispersed. Furthermore, the dispersion-treated solution was filtered with a polyflon filter (trade name: PF-040, manufactured by Advantech Toyo Co., Ltd.) to prepare a dispersion.

  Thereafter, 90 parts of a charge transport material (hole transport material) represented by the following structural formula (4),

70 parts 1,1,2,2,3,3,4-heptafluorocyclopentane and 70 parts 1-propanol were added to the dispersion. This was filtered with a polyflon filter (trade name: PF-020, manufactured by Advantech Toyo Co., Ltd.) to prepare a second paint for a charge transport layer.

  The second charge transport layer paint was applied onto the charge transport layer using the second charge transport layer paint, and then dried in an oven at 50 ° C. for 10 minutes in the air. After that, electron beam irradiation was performed for 1.6 seconds in a nitrogen atmosphere while rotating the support at 200 rpm under conditions of an acceleration voltage of 150 kV and a beam current of 3.0 mA. Subsequently, the temperature around the support was raised from 25 ° C. to 125 ° C. over 30 seconds in a nitrogen atmosphere, and the curing reaction of the substance contained in the second charge transport layer was performed. In addition, when the absorbed dose of the electron beam at this time was measured, it was 15 kGy. The oxygen concentration in the electron beam irradiation and heat curing reaction atmosphere was 15 ppm or less. The support subjected to the above treatment is naturally cooled to 25 ° C. in the atmosphere, and then heated in the atmosphere for 30 minutes in an oven heated to 100 ° C., and is positioned 130 mm from the upper end of the support. A second charge transport layer having an average film thickness of 5 μm was formed to obtain an electrophotographic photosensitive member.

<Formation of concave shape by excimer laser>
A concave portion was formed on the outermost surface layer of the obtained electrophotographic photoreceptor using a KrF excimer laser (wavelength λ = 248 nm). At this time, as shown in FIG. 17, it was performed using a quartz glass mask having a pattern in which circular laser light transmitting portions 5 having a diameter of 30 μm are arranged at intervals of 10 μm. The irradiation energy of the excimer laser was 0.9 J / cm ³ and the irradiation area per irradiation was 2 mm square. As shown in FIG. 9, the workpiece was rotated, and irradiation was performed while shifting the irradiation position in the axial direction.

<Observation of formed concave part>
When the surface shape of the obtained electrophotographic photosensitive member was enlarged and observed using a laser microscope (VK-9500, manufactured by Keyence Corporation), the major axis diameter Rpc was 8.6 μm and the minor axis diameter Lpc was 8 in the arrangement shown in FIG. It was confirmed that a concave portion having a diameter R.6 μm of 0.9 μm was formed.

  Further, a total of 100 regions obtained by dividing the surface of the electrophotographic photosensitive member into four equal parts in the rotational direction of the photosensitive member and 25 equal parts in the direction orthogonal to the rotational direction of the photosensitive member are defined as region A, and a total of 100 points. In each region A, a square region B having a side of 100 μm and having a side parallel to the photoconductor rotation direction was provided. When each of the regions B is divided into 500 equal parts by 499 straight lines orthogonal to the photoconductor rotation direction, all of the 499 straight lines overlap with the formed concave portion in all 100 regions B. It was confirmed that

  These results are shown in Table 1.

<Characteristic evaluation of electrophotographic process having electrophotographic photosensitive member and charging roller>
A charging member used for the evaluation was prepared by the following procedure.

First, the elastic layer was produced by the following method.
Epichlorohydrin rubber terpolymer 100 parts by mass (epichlorohydrin: ethylene oxide: allyl glycidyl ether = 40 mol%: 56 mol%: 4 mol%)
Light calcium carbonate 30 parts by weight Aliphatic polyester plasticizer 5 parts by weight Zinc stearate 1 part by weight Anti-aging agent MB (2-mercaptobenzimidazole) 0.5 parts by weight Zinc oxide 5 parts by weight Carbon black (untreated surface) 5 parts by mass (average particle size: 0.2 μm, volume resistivity: 0.1 Ω · cm)
2 parts by mass of a quaternary ammonium salt represented by the following structural formula

  The above materials were kneaded for 10 minutes in a closed mixer adjusted to 50 ° C. to prepare a raw material compound. In this compound, 100 parts by mass of raw material epichlorohydrin rubber, 1 part by mass of sulfur as a vulcanizing agent, 1 part by mass of DM (dibenzothiazyl sulfide) as a vulcanization accelerator and TS (tetramethylthiuram monosulfide) 0.5 parts by mass was added and kneaded for 10 minutes in a two-roll mill cooled to 20 ° C. The resulting compound is molded on a φ6mm stainless steel core with an extrusion molding machine to form a roller with an outer diameter of φ15mm, heated and steam vulcanized, and then polished to an outer diameter of φ10mm. An elastic layer was obtained. At this time, a wide polishing method was employed in the polishing process. The roller length was 232 mm.

Next, as a paint for the surface layer,
Caprolactone-modified acrylic polyol solution 100 parts by mass Methyl isobutyl ketone 250 parts by mass Conductive tin oxide (treated with trifluoropropyltrimethoxysilane) 130 parts by mass (average particle size: 0.05 μm, volume resistivity: 10 ³ Ω · cm)
Hydrophobic silica (dimethylpolysiloxane treated product) 3 parts by mass (average particle size: 0.02 μm, volume resistivity: 10 ¹⁶ Ω · cm)
Modified dimethyl silicone oil 0.08 parts by mass Cross-linked PMMA particles (average particle size: 4.98 μm) Using 80 parts by mass, a glass bottle was used as a container to prepare a mixed solution. This was filled with glass beads (average particle diameter φ0.8 mm) as a dispersion medium so that the filling rate would be 80%, and dispersed for 18 hours using a paint shaker disperser. To the dispersion solution, a mixture of hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI) 1: 1 butanone oxime block body is added so that NCO / OH = 1.0, and coating for surface layer for dip coating Was prepared.

  The surface layer coating was applied twice on the surface of the elastic layer by dip coating and air-dried, and then dried at a temperature of 160 ° C. for 1 hour.

  With respect to the manufactured charging roller, the ten-point average roughness (Rzjis) was measured by the method described above, and it was 4.4 μm.

  The particle size distribution of the fine particles added to the surface layer was measured using a laser diffraction particle size distribution analyzer SALD-7000 manufactured by Shimadzu Corporation. The range of the particle size that can be measured is 0.015 μm or more and 500 μm or less.

  The electrophotographic photosensitive member and the charging roller of the present invention thus produced were mounted on a Color LaserJet-4650 of a HP laser beam printer in an environment of 15 ° C./10% RH. The image after endurance of 4000 sheets was evaluated. Details are as follows.

  The produced electrophotographic photosensitive member was mounted on a cyan color process cartridge of Color LaserJet-4650 and mounted on a cyan process cartridge station for evaluation.

  At the time of paper passing, a full color printing operation was performed in a mode in which a character image having a printing rate of 2% for each color was continuously output as letter paper, and 4000 images were output.

  Then, at the start of evaluation and at the end of 4000 sheets, a halftone image having a 1-dot Keima pattern was output as a sample for image evaluation.

  At the end of 4000 sheets, a solid white image evaluation sample was output by adjusting the charging bias to set the dark portion potential (Vd) to −500 V and the developing bias to −550 V. This image was used for the study of charging stripes.

The criteria for image evaluation are as follows.
(Halftone image of Keima pattern)
A: No charging streaks B: Little charging streaks C: Charging streaks are slightly observed D: Charging streaks are observed (Adjustment of charging bias to set dark part potential (Vd) to −500 V, development Solid white image with a bias of -550V)
A: The number of clear charging lines was 10 or less per one drum revolution.
B: Clear charging streaks were 11 or more and 50 or less per drum circumference.
C: Clear charging streaks were 51 or more per drum circumference.

  The results are shown in Table 1.

(Example 2)
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1.
<Formation of concave shape by excimer laser>
A concave portion was formed in the same manner as in Example 1 except that the diameter of the circular laser beam transmitting portion in the quartz glass mask was changed to 9 μm and the interval was changed to 3 μm.
<Observation of formed concave portion and evaluation of characteristics of electrophotographic process having electrophotographic photosensitive member and charging roller>
Surface shape measurement and characteristic evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 3)
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1.
<Formation of concave shape by excimer laser>
A concave portion was formed in the same manner as in Example 2 except that the irradiation energy of the excimer laser was changed to 1.5 J / cm ³ .
<Observation of formed concave portion and evaluation of characteristics of electrophotographic process having electrophotographic photosensitive member and charging roller>
Surface shape measurement and characteristic evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

Example 4
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1.
<Formation of concave shape by excimer laser>
A concave portion was formed in the same manner as in Example 1 except that the diameter of the circular laser beam transmitting portion in the quartz glass mask was changed to 6 μm and the interval was changed to 2 μm.
<Observation of formed concave portion and evaluation of characteristics of electrophotographic process having electrophotographic photosensitive member and charging roller>
Surface shape measurement and characteristic evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 5)
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1.
<Formation of concave shaped part by mold press-fit shape transfer>
To the resulting electrophotographic photosensitive member, in the apparatus shown in FIG. 12, it has an array of cylinder shown in FIG. 14, a diameter _{R M} 1.0 .mu.m, with a cylindrical height _{H M} is 3.0μm Shape transfer was performed by pressurizing the mold for shape transfer. At this time, the temperature of the electrophotographic photosensitive member and the mold is controlled so that the temperature of the charge transport layer in the pressurizing portion becomes 110 ° C., and the photosensitive member is rotated in the circumferential direction while being pressurized at a pressure of 5 MPa. Shape transfer was performed.
<Observation of formed concave portion and evaluation of characteristics of electrophotographic process having electrophotographic photosensitive member and charging roller>
When surface shape measurement was performed in the same manner as in Example 1, concave portions were formed in the arrangement of FIG. Table 1 shows the results of surface shape measurement and characteristic evaluation as in Example 1.

(Example 6)
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1.
<Formation of concave shaped part by mold press-fit shape transfer>
The cylinder diameter _{R M} of the mold 4.5 [mu] m, except for cylinder height _{H M} and 10.0μm was carried out by following the procedure of shape transfer as in Example 5.
<Observation of formed concave portion and evaluation of characteristics of electrophotographic process having electrophotographic photosensitive member and charging roller>
Surface shape measurement and characteristic evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 7)
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1.
<Formation of concave shaped part by mold press-fit shape transfer>
1.0μm cylindrical diameter _{R M} of the mold, except that a cylinder the height _{H M} and 2.0μm was carried out by following the procedure of shape transfer as in Example 5.
<Observation of formed concave portion and evaluation of characteristics of electrophotographic process having electrophotographic photosensitive member and charging roller>
Surface shape measurement and characteristic evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 8)
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1.
<Formation of concave shaped part by mold press-fit shape transfer>
The cylinder diameter _{R M} of the mold 4.5 [mu] m, except for cylinder height _{H M} and 1.7μm was carried out by following the procedure of shape transfer as in Example 5.
<Observation of formed concave portion and evaluation of characteristics of electrophotographic process having electrophotographic photosensitive member and charging roller>
Surface shape measurement and characteristic evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

Example 9
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1.
<Formation of concave shaped part by mold press-fit shape transfer>
Except that the cylinder height H _M of the mold and 1.4μm was carried out by following the procedure of shape transfer as in Example 5.
<Observation of formed concave portion and evaluation of characteristics of electrophotographic process having electrophotographic photosensitive member and charging roller>
Surface shape measurement and characteristic evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 10)
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1.
<Formation of concave shaped part by mold press-fit shape transfer>
2.5μm cylindrical diameter _{R M} of the mold, except that the 3.0μm cylindrical height _{H M} was carried out by following the procedure of shape transfer as in Example 5.
<Observation of formed concave portion and evaluation of characteristics of electrophotographic process having electrophotographic photosensitive member and charging roller>
Surface shape measurement and characteristic evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 11)
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1.
<Formation of concave shaped part by mold press-fit shape transfer>
The cylinder diameter _{R M} of the mold 2.2 .mu.m, except that a cylinder the height _{H M} and 1.7μm was carried out by following the procedure of shape transfer as in Example 5.
<Observation of formed concave portion and evaluation of characteristics of electrophotographic process having electrophotographic photosensitive member and charging roller>
Surface shape measurement and characteristic evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 12)
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1.
<Formation of concave shaped part by mold press-fit shape transfer>
The cylinder diameter _{R M} of the mold 4.0 .mu.m, except that a cylinder the height _{H M} and 5.0μm was carried out by following the procedure of shape transfer as in Example 5.
<Observation of formed concave portion and evaluation of characteristics of electrophotographic process having electrophotographic photosensitive member and charging roller>
Surface shape measurement and characteristic evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 13)
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1.
<Formation of concave shaped part by mold press-fit shape transfer>
Shape transfer was performed in the same manner as in Example 5 except that the arrangement of the columns in the mold was changed to the arrangement shown in FIG.
<Observation of formed concave portion and evaluation of characteristics of electrophotographic process having electrophotographic photosensitive member and charging roller>
When the surface shape measurement was performed in the same manner as in Example 1, concave portions were formed in the arrangement shown in FIG. Table 1 shows the results of surface shape measurement and characteristic evaluation as in Example 1.

(Example 14)
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1.
<Formation of concave shaped part by mold press-fit shape transfer>
Shape transfer was performed in the same manner as in Example 5 except that the arrangement of the columns in the mold was changed to the arrangement shown in FIG.
<Observation of formed concave portion and evaluation of characteristics of electrophotographic process having electrophotographic photosensitive member and charging roller>
When surface shape measurement was performed in the same manner as in Example 1, concave portions were formed in the arrangement shown in FIG. Table 1 shows the results of surface shape measurement and characteristic evaluation as in Example 1.

(Example 15)
<Production of electrophotographic photoreceptor>
In the same manner as in Example 1, a conductive layer, an intermediate layer, and a charge generation layer were produced on a support.

  Next, 70 parts of a charge transport material (hole transport material) represented by the above formula (2), 100 parts of a copolymerized polyarylate resin represented by the following structural formula (5) were mixed with 600 parts of chlorobenzene and 200 parts of methylal. A charge transport layer coating material was prepared by dissolving in a solvent. Using this, the charge transport layer is dip coated on the charge generation layer and dried in an oven heated to 110 ° C. for 30 minutes, whereby the average film thickness at a position of 130 mm from the upper end of the support is 15 μm. A charge transport layer was formed.

  In the formula, m and n represent a ratio (copolymerization ratio) of repeating units in the resin, and in the resin, m: n = 7: 3.

  The molar ratio of the terephthalic acid structure to the isophthalic acid structure in the polyarylate resin (terephthalic acid structure: isophthalic acid structure) is 50:50. The weight average molecular weight (Mw) is 130,000.

  In the present invention, the weight average molecular weight of the resin is measured as follows according to a conventional method.

  That is, after placing the measurement target resin in tetrahydrofuran and allowing it to stand for several hours, the measurement target resin and tetrahydrofuran are mixed well with shaking (mixed until the measurement target resin is completely united), and further left to stand for 12 hours or more. .

  Then, what passed the sample processing filter Mysori disk H-25-5 by Tosoh Corporation was made into the sample for GPC (gel permeation chromatography).

  Next, the column is stabilized in a heat chamber at 40 ° C., tetrahydrofuran is flowed through the column at this temperature at a flow rate of 1 ml / min, 10 μl of GPC sample is injected, and the weight average molecular weight of the measurement target resin Was measured. A column TSKgel Super HM-M manufactured by Tosoh Corporation was used as the column.

  In measuring the weight average molecular weight of the measurement target resin, the molecular weight distribution of the measurement target resin was calculated from the relationship between the logarithmic value of the calibration curve prepared from several types of monodisperse polystyrene standard samples and the number of counts. In the standard polystyrene sample for preparing a calibration curve, the molecular weight of monodisperse polystyrene manufactured by Aldrich is 3,500, 12,000, 40,000, 75,000, 98,000, 120,000, 240,000, Ten samples of 500,000, 800,000 and 1,800,000 were used. An RI (refractive index) detector was used as the detector.

An electrophotographic photosensitive member produced by the method described above, was carried out by following the procedure of shape transfer to Example 5 except that the cylinder diameter R _M of the mold 2.5 [mu] m, a cylindrical height H _M and 5.0μm .
<Observation of formed concave portion and evaluation of characteristics of electrophotographic process having electrophotographic photosensitive member and charging roller>
Surface shape measurement and characteristic evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 16)
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 15.
<Formation of concave shaped part by mold press-fit shape transfer>
Except that the cylinder height H _M of the mold and 5.0μm was carried out by following the procedure of shape transfer as in Example 5.
<Observation of formed concave portion and evaluation of characteristics of electrophotographic process having electrophotographic photosensitive member and charging roller>
Surface shape measurement and characteristic evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 17)
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 15.
<Formation of concave shaped part by mold press-fit shape transfer>
The cylinder diameter _{R M} of the mold 3.0 [mu] m, except that the 3.0 [mu] m cylindrical height _{H M} was carried out by following the procedure of shape transfer as in Example 5.
<Observation of formed concave portion and evaluation of characteristics of electrophotographic process having electrophotographic photosensitive member and charging roller>
Surface shape measurement and characteristic evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 18)
<Production of electrophotographic photoreceptor>
In the same manner as in Example 1, a conductive layer, an intermediate layer, and a charge generation layer were produced on a support.

Next, 7 parts of the charge transporting material (hole transporting material) represented by the above formula (2) and 10 parts of polycarbonate resin (Idemitsu Kosan, Tufzette (registered trademark) B-500) are dissolved in a mixed solvent of 80 parts of dichloromethane. Thus, a charge transport layer coating material was prepared. Using this, the charge transport layer is dip coated on the charge generation layer and dried in an oven heated to 110 ° C. for 30 minutes, whereby the average film thickness at a position of 130 mm from the upper end of the support is 15 μm. A charge transport layer was formed.
<Formation of concave shaped part by mold press-fit shape transfer>
Shape transfer was performed in the same manner as in Example 7.
<Observation of formed concave portion and evaluation of characteristics of electrophotographic process having electrophotographic photosensitive member and charging roller>
Surface shape measurement and characteristic evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 19)
<Production of electrophotographic photoreceptor>
In the same manner as in Example 18, an electrophotographic photosensitive member was produced.
<Formation of concave shaped part by mold press-fit shape transfer>
Except that the cylinder height H _M of the mold and 1.0μm was carried out by following the procedure of shape transfer as in Example 5.
<Observation of formed concave portion and evaluation of characteristics of electrophotographic process having electrophotographic photosensitive member and charging roller>
Surface shape measurement and characteristic evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 20)
<Preparation of electrophotographic photosensitive member and formation of concave portion by condensation method>
In the same manner as in Example 1, a conductive layer, an intermediate layer, and a charge generation layer were produced on a support.

  Next, a polycarbonate resin (Iupilon Z-400, Mitsubishi Engineering Plastics Co., Ltd.) comprising 10 parts of a charge transport material having the structure represented by the structural formula (2) and a repeating unit represented by the structural formula (3). ) Produced) 10 parts of [viscosity average molecular weight (Mv) 40,000] was dissolved in a mixed solvent of 65 parts of chlorobenzene and 35 parts of dimethoxymethane to prepare a coating solution for a surface layer containing a charge transport material. The step of preparing the surface layer coating solution was performed in a state where the relative humidity was 45% and the ambient temperature was 25 ° C.

  The surface layer coating solution prepared as described above was dip-coated on the charge generation layer, and the surface layer coating solution was applied on the cylindrical support. The step of applying the surface layer coating solution was performed at a relative humidity of 45% and an atmospheric temperature of 25 ° C.

  After 60 seconds from the end of the coating process, the cylindrical support in which the coating liquid for the surface layer is coated in the apparatus for holding the cylindrical support, in which the inside of the apparatus is in a state where the relative humidity is 70% and the atmospheric temperature is 60 ° C. The body was held for 120 seconds.

After 60 seconds from the end of the cylindrical support holding process, the cylindrical support is put in a blower dryer that has been heated to 120 ° C. in advance, and the drying process is performed for 60 minutes. An electrophotographic photosensitive member was obtained by forming a charge transport layer having a thickness of 15 μm.
<Observation of formed concave portion and evaluation of characteristics of electrophotographic process having electrophotographic photosensitive member and charging roller>
Surface shape measurement and characteristic evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 21)
<Preparation of electrophotographic photosensitive member and formation of concave portion by condensation method>
An electrophotographic photosensitive member was produced in the same manner as in Example 20 except that the atmospheric temperature in the cylindrical support holding step was changed to 45 ° C.
<Observation of formed concave portion and evaluation of characteristics of electrophotographic process having electrophotographic photosensitive member and charging roller>
Surface shape measurement and characteristic evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 22)
<Preparation of electrophotographic photosensitive member and formation of concave portion by condensation method>
In the surface layer coating solution, the binder resin in the surface layer coating solution is changed to a polyarylate resin (weight average molecular weight (Mw): 120,000) having a repeating structural unit represented by the structural formula (5). An electrophotographic photosensitive member was prepared in the same manner as in Example 20 except that the solvent was changed from a mixed solvent of 65 parts of chlorobenzene and 35 parts of dimethoxymethane to 50 parts of chlorobenzene, 10 parts of oxolane and 40 parts of dimethoxymethane.

The molar ratio of the terephthalic acid structure to the isophthalic acid structure in the polyarylate resin (terephthalic acid structure: isophthalic acid structure) is 50:50.
<Observation of formed concave portion and evaluation of characteristics of electrophotographic process having electrophotographic photosensitive member and charging roller>
Surface shape measurement and characteristic evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 23)
<Preparation of electrophotographic photosensitive member and formation of concave portion by condensation method>
An electrophotographic photosensitive member was produced in the same manner as in Example 22, except that the time for holding the cylindrical support coated with the surface layer coating liquid in the cylindrical support holding process apparatus was changed to 80 seconds. .
<Observation of formed concave portion and evaluation of characteristics of electrophotographic process having electrophotographic photosensitive member and charging roller>
Surface shape measurement and characteristic evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 24)
<Preparation of electrophotographic photosensitive member and formation of concave portion by condensation method>
An electrophotographic photosensitive member was produced in the same manner as in Example 22, except that the time for holding the cylindrical support coated with the surface layer coating solution in the cylindrical support holding process apparatus was changed to 60 seconds. .
<Observation of formed concave portion and evaluation of characteristics of electrophotographic process having electrophotographic photosensitive member and charging roller>
Surface shape measurement and characteristic evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 25)
<Preparation of electrophotographic photosensitive member and formation of concave portion by condensation method>
10 seconds after the coating process is finished, the cylindrical support in which the coating liquid for the surface layer is coated in the apparatus for holding the cylindrical support, in which the inside of the apparatus is in a state where the relative humidity is 50% and the atmospheric temperature is 30 ° C. It was changed to hold the body for 10 seconds, and after 240 seconds from the end of the cylindrical support holding process, the cylindrical support was put into a blower dryer that had been heated to 120 ° C. in advance, and the drying process was performed. An electrophotographic photosensitive member was produced in the same manner as in Example 22 except that the time was changed to 60 minutes.
<Observation of formed concave portion and evaluation of characteristics of electrophotographic process having electrophotographic photosensitive member and charging roller>
Surface shape measurement and characteristic evaluation were performed in the same manner as in Example 1. The results are shown in Table 1.

(Example 26)
<Preparation of electrophotographic photosensitive member, formation of concave shape portion and observation of formed concave shape portion>
An electrophotographic photosensitive member was produced in the same manner as in Example 5.
<Characteristic evaluation of electrophotographic process having electrophotographic photosensitive member and charging roller>
In the production of the charging roller to be mounted, the characteristic evaluation was performed in the same manner as in Example 5 except that the average particle diameter of the PMMA particles added to the surface layer was 2.53 μm. The results are shown in Table 1. The ten-point average roughness Rzjis of the charging roller at that time was 2.9 μm.

(Example 27)
<Preparation of electrophotographic photosensitive member, formation of concave shape portion and observation of formed concave shape portion>
An electrophotographic photosensitive member was produced in the same manner as in Example 15.
<Characteristic evaluation of electrophotographic process having electrophotographic photosensitive member and charging roller>
In the production of the charging roller to be mounted, the characteristic evaluation was performed in the same manner as in Example 15 except that the average particle diameter of the PMMA particles added to the surface layer was 2.53 μm. The results are shown in Table 1. The ten-point average roughness Rzjis of the charging roller at that time was 2.9 μm.

(Example 28)
<Preparation of electrophotographic photosensitive member, formation of concave shape portion and observation of formed concave shape portion>
In the same manner as in Example 18, an electrophotographic photosensitive member was produced.
<Characteristic evaluation of electrophotographic process having electrophotographic photosensitive member and charging roller>
In the production of the charging roller to be mounted, the characteristic evaluation was performed in the same manner as in Example 18 except that the average particle diameter of the PMMA particles added to the surface layer was 2.53 μm. The results are shown in Table 1. The ten-point average roughness Rzjis of the charging roller at that time was 2.9 μm.

(Example 29)
<Preparation of electrophotographic photosensitive member, formation of concave shape portion and observation of formed concave shape portion>
An electrophotographic photosensitive member was produced in the same manner as in Example 1.
<Characteristic evaluation of electrophotographic process having electrophotographic photosensitive member and charging roller>
In the production of the charging roller to be mounted, the characteristics were evaluated in the same manner as in Example 1 except that no PMMA particles were added to the surface layer. The results are shown in Table 1. The ten-point average roughness Rzjis of the charging roller at that time was 1.5 μm.

(Example 30)
<Preparation of electrophotographic photosensitive member, formation of concave shape portion and observation of formed concave shape portion>
An electrophotographic photosensitive member was produced in the same manner as in Example 9.
<Characteristic evaluation of electrophotographic process having electrophotographic photosensitive member and charging roller>
In the production of the charging roller to be mounted, the characteristics were evaluated in the same manner as in Example 9 except that no PMMA particles were added to the surface layer. The results are shown in Table 1. The ten-point average roughness Rzjis of the charging roller at that time was 1.5 μm.

(Example 31)
<Preparation of electrophotographic photosensitive member, formation of concave shape portion and observation of formed concave shape portion>
In the same manner as in Example 17, an electrophotographic photosensitive member was produced.
<Characteristic evaluation of electrophotographic process having electrophotographic photosensitive member and charging roller>
In the production of the charging roller to be mounted, the characteristic evaluation was performed in the same manner as in Example 17 except that the PMMA particles were not added to the surface layer. The results are shown in Table 1. The ten-point average roughness Rzjis of the charging roller at that time was 1.5 μm.

(Example 32)
<Preparation of electrophotographic photosensitive member, formation of concave shape portion and observation of formed concave shape portion>
An electrophotographic photosensitive member was produced in the same manner as in Example 20.
<Characteristic evaluation of electrophotographic process having electrophotographic photosensitive member and charging roller>
In the production of the charging roller to be mounted, the characteristic evaluation was performed in the same manner as in Example 20 except that the PMMA particles were not added to the surface layer. The results are shown in Table 1. The ten-point average roughness Rzjis of the charging roller at that time was 1.5 μm.

(Example 33)
<Preparation of electrophotographic photosensitive member, formation of concave shape portion and observation of formed concave shape portion>
An electrophotographic photosensitive member was produced in the same manner as in Example 15.
<Characteristic evaluation of electrophotographic process having electrophotographic photosensitive member and charging roller>
In the production of the charging roller to be mounted, the characteristic evaluation was performed in the same manner as in Example 15 except that the average particle size of the PMMA particles added to the surface layer was 1.09 μm. The results are shown in Table 1. The ten-point average roughness Rzjis of the charging roller at that time was 1.3 μm.

(Comparative Example 1)
<Production of electrophotographic photoreceptor>
In the same manner as in Example 18, an electrophotographic photosensitive member was produced.
<Formation of concave shaped part by mold press-fit shape transfer>
In the apparatus shown in FIG. 12, shape transfer was performed in the same manner as in Example 18 except that the arrangement of the cylinders of the mold was changed as shown in FIG.
<Observation of formed concave portion and evaluation of characteristics of electrophotographic process having electrophotographic photosensitive member and charging roller>
When the surface shape measurement was performed in the same manner as in Example 18, concave portions were formed in the arrangement shown in FIG. The results of surface shape measurement and characteristic evaluation as in Example 18 are shown in Table 1.

(Comparative Example 2)
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 18, and the surface of the electrophotographic photosensitive member was roughened by a sandblasting method in which glass beads having an average particle diameter of 35 μm were sprayed on the surface of the photosensitive member.
<Observation of surface of electrophotographic photoreceptor and evaluation of characteristics of electrophotographic process having electrophotographic photoreceptor and charging roller>
In the same manner as in Example 18, surface shape measurement and characteristic evaluation were performed. The results are shown in Table 1.

(Comparative Example 3)
<Production of electrophotographic photoreceptor>
An electrophotographic photoreceptor was produced in the same manner as in Example 18, and the surface of the photoreceptor was not processed.
<Observation of surface of electrophotographic photoreceptor and evaluation of characteristics of electrophotographic process having electrophotographic photoreceptor and charging roller>
In the same manner as in Example 18, surface shape measurement and characteristic evaluation were performed. The results are shown in Table 1.

It is a figure which shows the example of the surface shape of the concave shape part in this invention. The arrow in the figure indicates the major axis diameter (Rpc) in the concave portion. It is a figure which shows the example of the surface shape of the concave shape part in this invention. The arrow in the figure indicates the short axis diameter (Lpc) in the concave portion. It is a figure which shows the example of the cross-sectional shape of the concave shape part in this invention. The arrows in the figure indicate the major axis diameter (Rpc) and the distance (Rdv) between the deepest part and the aperture surface in the concave part. 1 is a view showing a support in an electrophotographic photosensitive member of the present invention and a photosensitive layer 2 provided on the support (a straight line OP in the drawing is a straight line orthogonal to the rotation direction of the photosensitive member on the photosensitive layer). ). It is a figure which shows how to take the area | region A in this invention (a part of area | region A was abbreviate | omitted and shown in figure). FIG. 6 is a diagram in which the region B in the present invention is divided into 500 equal parts by 499 straight lines parallel to the photoconductor rotation direction (only a part of the straight lines are shown in the figure). It is a figure which shows the example of the overlap of the straight line and the concave shape part in the area | region B in this invention. It is an image figure of the assumption mechanism in this invention. It is a figure which shows the example (partial enlarged view) of the arrangement pattern of the laser mask in this invention. It is a figure which shows the example of the schematic of the laser processing apparatus in this invention. It is a figure which shows the example (partial enlarged view) of the arrangement pattern of the concave shape part of the outermost surface of the photoreceptor obtained by this invention. It is a figure which shows the example of the schematic of the press-contact shape transfer processing apparatus by the mold in this invention. It is a figure which shows another example of the schematic of the press-contact shape transfer processing apparatus by the mold in this invention. It is a figure which shows the example of the shape (partial enlarged view of a photoreceptor contact surface) of the mold in this invention. It is a figure which shows the example of the shape of the mold in the present invention (partial enlarged view of a photoconductor contact surface section). 1 is a diagram illustrating an example of a schematic configuration of an electrophotographic apparatus including a process cartridge having an electrophotographic photosensitive member according to the present invention. It is a figure which shows the example (partial enlarged view) of the arrangement pattern of the laser mask used in Example 1. FIG. FIG. 3 is a diagram illustrating an array pattern (partially enlarged view) of concave portions on the outermost surface of the photoconductor in Example 1; It is a figure which shows the shape of the mold (partial enlarged view of a photoreceptor contact surface) used in Example 12. FIG. 16 is a diagram showing an array pattern (partially enlarged view) of concave-shaped portions on the outermost surface of the photoreceptor in Example 12. It is a figure which shows the shape (partial enlarged view of a photoreceptor contact surface) of the mold used in Example 13. FIG. 17 is a diagram showing an array pattern (partially enlarged view) of concave-shaped portions on the outermost surface of the photoconductor in Example 13; It is a figure which shows the shape of the mold (partial enlarged view of a photoreceptor contact surface) used in Comparative Example 1. 6 is a diagram showing an arrangement pattern (partially enlarged view) of concave-shaped portions on the outermost surface of the photoreceptor in Comparative Example 1. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Support body 2 Photosensitive layer 3 Concave shape part 4 Laser light shielding part 5 Laser light transmission part 6 Excimer laser light irradiator 7 Work rotation motor 8 Work moving device 9 Photosensitive drum 10 Concave part non-formation part 11 Concave part Forming unit 12 Pressurizing device 13 Mold 14 Photoconductor 15 Electrophotographic photosensitive member 16 Shaft 17 Charging means 18 Exposure light 19 Developing means 20 Transfer means 21 Cleaning means 22 Fixing means 23 Process cartridge 24 Guide means 25 Transfer material 26 Mold substrate 27 Mold Cylinder

Claims (2)

An electrophotographic photosensitive member having a photosensitive layer provided on a support and the support, and a small contact charging member than the average roughness Rzjis ten-point surface is 5.0 .mu.m, detachably attached to an electrophotographic apparatus main body In the process cartridge ,
The electrophotographic photosensitive member, the surface for forming an electrostatic latent image, comprising a plurality of each independent depressed portions,
Each of the concave portions, the long axis diameter of the surface openings (Rpc) is minor axis diameter of the surface openings I der below 10 [mu] m (Lpc) is the deepest and the open I der than 1.0μm A concave portion having a distance (Rdv) to the hole surface of 0.3 μm or more;
Each of the concave-shaped portion, at 4 99 straight lines you perpendicular to the photosensitive member rotation direction for the region of the square parallel one side 100μm to an edge of the photosensitive member rotation direction at the surface of the electrophotographic photosensitive member 500 to overlap with so that the 400 or more present is concave shaped portion of the 499 straight lines when equal parts, and wherein <br/> being disposed on the entire surface of the electrophotographic photosensitive member To process cartridge. An electrophotographic photosensitive member to have a photosensitive layer provided on a support and the support, the contact charging the surface of the electrophotographic photosensitive member average roughness Rzjis ten-point of the surface with a small contact charging member than 5.0μm Charging means, exposing means for exposing the charged electrophotographic photosensitive member to form an electrostatic latent image on the surface of the electrophotographic photosensitive member, and electrostatic forming on the surface of the electrophotographic photosensitive member Developing means for developing a latent image with toner to form a toner image on the surface of the electrophotographic photosensitive member; and transfer means for transferring the toner image formed on the surface of the electrophotographic photosensitive member onto a transfer material. In the electrophotographic apparatus provided,
The electrophotographic photosensitive member has a plurality of independent concave portions on the surface for forming an electrostatic latent image,
Each of the concave portions, the long axis diameter of the surface openings (Rpc) is minor axis diameter of the surface openings I der below 10 [mu] m (Lpc) is the deepest and the open I der than 1.0μm A concave portion having a distance (Rdv) to the hole surface of 0.3 μm or more;
Each of the concave-shaped portion, at 4 99 straight lines you perpendicular to the photosensitive member rotation direction for the region of the square parallel one side 100μm to an edge of the photosensitive member rotation direction at the surface of the electrophotographic photosensitive member 500 to overlap with so that the 400 or more present is concave shaped portion of the 499 straight lines when equal parts, and wherein <br/> being disposed on the entire surface of the electrophotographic photosensitive member An electrophotographic device.