JP2017134279A - Electrophotographic photoreceptor, process cartridge and electrophotographic device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electro-photographic photoreceptor, a process cartridge having the electro- photographic photoreceptor, and an electro-photographic device which reduce a strip-like image defect generated by a low print mode output under a high temperature environment.SOLUTION: In an electro-photographic photoreceptor having a photosensitive layer on a cylindrical support medium, a surface of the electro-photographic photoreceptor has a plurality of recesses each of which is independent from one another, and a width in the axial direction of the electro-photographic photoreceptor of an opening surface of the recess is not less than 20 μm and not more than 80 μm, and when a square region having one side of 500 μm is arranged at an arbitrary position of the electro-photographic photoreceptor, a sum total of the area of the opening surface of the recess in the square region having one side of 500 μm is 100000 μm. The recess has a specific shape, and the plurality of recesses has an angle in a peripheral direction and an axial direction of the electro-photographic photoreceptor in arrangement direction of the adjacent recesses.SELECTED DRAWING: Figure 2

Description

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

Since an electric external force such as charging or cleaning or a mechanical external force is applied to the surface of the electrophotographic photosensitive member, durability against such external force (such as wear resistance) is required.
In response to this requirement, conventionally, improved techniques such as using a highly wear-resistant resin (such as a curable resin) for the surface layer of the electrophotographic photosensitive member have been used.
On the other hand, problems caused by increasing the wear resistance of the surface of the electrophotographic photosensitive member include a decrease in image flow and cleaning performance.
In the image flow, the material used for the surface layer of the electrophotographic photosensitive member deteriorates due to ozone or nitrogen oxide generated by charging of the surface of the electrophotographic photosensitive member, or the surface of the electrophotographic photosensitive member due to moisture adsorption. Is considered to be caused by a decrease in resistance. The higher the abrasion resistance of the surface of the electrophotographic photosensitive member, the more difficult the surface of the electrophotographic photosensitive member is refreshed (removal of materials that cause image flow such as deteriorated materials and adsorbed moisture), resulting in image flow. It becomes easy to do.

As a technique for improving image flow, Patent Document 1 discloses that a concave portion having a depth of 0.5 μm or more and 5 μm or less and a maximum opening diameter of 20 μm or more and 80 μm or less is formed on a surface of the electrophotographic photosensitive member in a square region having a side of 500 μm. area provided 10000 ² more 90000Myuemu ² or less, further by the area of the flat portion contained in a portion other than the recess provided 80000Myuemu ² more 240000Myuemu ² or less, dots even when allowed to stand an electrophotographic photosensitive member in a high-temperature and high-humidity environment A technique for improving reproducibility is disclosed.

Japanese Patent No. 5127799

  However, while the technique disclosed in Patent Document 1 has a very large effect on improving the image flow, when used for a long time in a low-humidity environment, the electrophotographic image has a streak-like image defect (hereinafter also referred to as a low-humidity durable streak). There remains room for improvement in that it may occur.

Based on the technique disclosed in Patent Document 1, the present inventors provide a concave portion having a depth of 0.5 μm or more and 5 μm or less and a longest opening diameter of 20 μm or more and 80 μm or less on the surface of the electrophotographic photosensitive member. The above-mentioned low-humidity endurance streak was improved by making the total area of the recesses 95,000 μm ² or more in a 500 μm square region.
However, a further improvement is that a streak-like image defect (hereinafter also referred to as H / H initial streak) occurs on a halftone image having a density of about 30% that is output after printing in a low print mode in a high temperature and high humidity environment. There remains room for.

  An object of the present invention is to provide an electrophotographic photosensitive member that reduces streak-like image defects caused by a low print mode output under a high temperature and high humidity environment, a process cartridge having the electrophotographic photosensitive member, and an electrophotographic apparatus. is there.

The present invention relates to an electrophotographic photosensitive member having a photosensitive layer on a cylindrical support, the surface of the electrophotographic photosensitive member having a plurality of independent concave portions, and an opening of the concave portion. The width of the surface in the axial direction of the electrophotographic photosensitive member is 20 μm or more and 80 μm or less, and when a square region having a side of 500 μm is arranged at an arbitrary position on the surface of the electrophotographic photosensitive member, The sum of the area of the opening surface of the concave shape portion is 100000 μm ² or more, and the contour shape of the opening surface of the concave shape portion has two contours on at least one end side in the circumferential direction of the electrophotographic photosensitive member. A straight line, two contour curves, or a vertex composed of one contour line and one contour curve, and the contour straight line or the contour curve forming the vertex is the electron on the contour straight line or the contour curve. Around the photoconductor The distance from the two points that are the farthest to the straight line A passing through the vertex to the straight line A gradually decreases toward the vertex, and the two points that are the farthest away from the straight line A. From the top to the top, the angle formed by the contour straight line or the tangent to the contour curve with respect to the axial direction of the electrophotographic photosensitive member is 45 ° or more and 90 ° or less, and the concave portion is the concave portion. The depth of the opening from the deepest surface is a shape that gradually decreases from the deepest point toward the apex, and the plurality of concave-shaped portions are arranged such that the direction of arrangement of adjacent concave-shaped portions is the electrophotographic photosensitive member. An electrophotographic photosensitive member having an angle in a circumferential direction and an axial direction of the body.

The present invention also provides a process cartridge having at least an electrophotographic photosensitive member having a photosensitive layer on a cylindrical support and a cleaning blade, wherein the surface of the electrophotographic photosensitive member has a plurality of independent concave portions. And the width of the opening of the concave portion in the axial direction of the electrophotographic photosensitive member is not less than 20 μm and not more than 80 μm, and an arbitrary position of a contact area with the cleaning blade on the surface of the electrophotographic photosensitive member When a square region having a side of 500 μm is disposed on the surface, the total area of the opening surface of the concave portion in the square region having a side of 500 μm is 100,000 μm ² or more, and the contour shape of the opening surface of the concave portion is The wheel which has the vertex which consists of two outline straight lines, two outline curves, or one outline straight line and one outline curve in the back end side of the rotation direction of a photographic photosensitive member, and forms this apex The straight line or the contour curve extends from the two points on the contour straight line or the contour curve that extend in the circumferential direction of the electrophotographic photosensitive member and the distance to the straight line A that passes through the vertex is farthest from the point. Thus, the distance to the straight line A gradually decreases, and the tangent line of the contour straight line or the contour curve is in the axial direction of the electrophotographic photosensitive member from the two points where the distance is the farthest to the vertex. The plurality of concave portions have an arrangement direction of adjacent concave portions having an angle with respect to the circumferential direction and the axial direction of the electrophotographic photosensitive member. This is a process cartridge.

  The present invention also provides the electrophotographic photosensitive member, charging means for charging the surface of the electrophotographic photosensitive member, and exposure for irradiating the charged surface of the electrophotographic photosensitive member with exposure light to form an electrostatic latent image. Developing means for developing the electrophotographic photosensitive member on which the electrostatic latent image is formed with toner, transfer means for transferring the toner image on the electrophotographic photosensitive member onto a transfer material, and the electrophotographic photosensitive member. An electrophotographic apparatus comprising a cleaning blade arranged in contact.

  According to the present invention, it is possible to provide an electrophotographic photosensitive member that reduces streak-like image defects caused by a low print mode output under a high temperature and high humidity environment, a process cartridge having the electrophotographic photosensitive member, and an electrophotographic apparatus. it can.

It is a figure which shows the example of fitting. (A): It is a figure which shows an example of the opening surface of the concave shape part of this invention. (B): It is circumferential direction sectional drawing in an example of the concave shape part of this invention. It is a figure which shows the example of the shape of the opening part of the concave shape part of the surface of the electrophotographic photoreceptor which concerns on this invention. It is a figure which shows the example of the shape of the circumferential cross section of the concave-shaped part of the surface of the electrophotographic photoreceptor which concerns on this invention. It is a figure which shows the example of the press-contact shape transfer processing apparatus for forming a concave shape part in the surface of an electrophotographic photoreceptor. FIG. 2 is a diagram showing an example of an electrophotographic apparatus provided with a process cartridge having the electrophotographic photosensitive member of the present invention. (A): It is a top view which shows the mold used by the manufacture example (corresponding to the comparative example 1) of the electrophotographic photosensitive member. (B): It is BB sectional drawing of the convex part in the mold shown by Fig.7 (a). (C): It is CC sectional drawing of the convex part in the mold shown by Fig.7 (a). (A): It is a top view which shows the mold used by the manufacture example (corresponding to the comparative example 2) of the electrophotographic photosensitive member. (B): It is BB sectional drawing of the convex part in the mold shown by Fig.8 (a). (C): It is CC sectional drawing of the convex part in the mold shown by Fig.8 (a). (A): It is a top view which shows the mold used by the manufacture example (corresponding to the comparative example 3) of the electrophotographic photosensitive member. (B): It is BB sectional drawing of the convex part in the mold shown by Fig.9 (a). (C): It is CC sectional drawing of the convex part in the mold shown by Fig.9 (a). (A): It is a top view which shows the mold used by the manufacture example (corresponding to the comparative example 4) of the electrophotographic photosensitive member. (B): It is BB sectional drawing of the convex part in the mold shown by Fig.10 (a). (C): It is CC sectional drawing of the convex part in the mold shown by Fig.10 (a). (A): It is a top view which shows the mold used by the manufacture example (corresponding to the comparative example 5) of the electrophotographic photosensitive member. (B): It is BB sectional drawing of the convex part in the mold shown by Fig.11 (a). (C): It is CC sectional drawing of the convex part in the mold shown by Fig.11 (a). (A): It is a top view which shows the mold used by the manufacture example (corresponding to the comparative example 6) of the electrophotographic photosensitive member. (B): It is BB sectional drawing of the convex part in the mold shown by Fig.12 (a). (C): It is CC sectional drawing of the convex part in the mold shown by Fig.12 (a). (A): It is a top view which shows the mold used by the manufacture example (corresponding to the comparative example 7) of the electrophotographic photosensitive member. (B): It is BB sectional drawing of the convex part in the mold shown by Fig.13 (a). (C): It is CC sectional drawing of the convex part in the mold shown by Fig.13 (a). (A): It is a top view which shows the mold used by the manufacture example (corresponding to the comparative example 8) of the electrophotographic photosensitive member. (B): It is BB sectional drawing of the convex part in the mold shown by Fig.14 (a). (C): It is CC sectional drawing of the convex part in the mold shown by Fig.14 (a). (A): It is a top view which shows the mold used by the manufacture example (corresponding to the comparative example 9) of the electrophotographic photosensitive member. (B): It is BB sectional drawing of the convex part in the mold shown by Fig.15 (a). (C): It is CC sectional drawing of the convex part in the mold shown by Fig.15 (a). (A): It is a top view which shows the mold used by the manufacture example (corresponding to Examples 1-4) of the electrophotographic photosensitive member. (B): It is BB sectional drawing of the convex part in the mold shown by Fig.16 (a). (C): It is CC sectional drawing of the convex part in the mold shown by Fig.16 (a). (A): It is a top view which shows the mold used by the manufacture example (corresponding to Examples 5-8) of an electrophotographic photosensitive member. (B): It is BB sectional drawing of the convex part in the mold shown by Fig.17 (a). (C): It is CC sectional drawing of the convex part in the mold shown by Fig.17 (a). (A): It is a top view which shows the mold used by the manufacture example (corresponding to Examples 9-12) of an electrophotographic photosensitive member. (B): It is BB sectional drawing of the convex part in the mold shown by Fig.18 (a). (C): It is CC sectional drawing of the convex part in the mold shown by Fig.18 (a).

There are two features of the present invention with respect to Patent Document 1.
The first point is that the sum of the areas of the opening surfaces of the concave portions on the surface of the electrophotographic photosensitive member is large.
The second point is a point where the concave portion has a specific shape shown below.
That is, the contour shape of the opening surface has two contour straight lines, two contour curves, or a vertex composed of one contour straight line and one contour curve on at least one end side in the circumferential direction of the electrophotographic photosensitive member. Have. The contour straight line or the contour curve that forms the vertex extends 2 in the circumferential direction of the electrophotographic photosensitive member on the contour straight line or the contour curve, and the distance 2 to the straight line A that passes through the vertex is the farthest 2 The distance to the straight line A gradually decreases from one point toward the vertex. Further, when the contour line or the contour curve is located on the contour line or the contour curve from the two points that are the farthest apart to the vertex, the contour line or the tangent of the contour curve is the electrophotographic image. The angle formed with respect to the axial direction of the photoreceptor is 45 ° or more and 90 ° or less. Further, the concave shape portion has a shape in which the depth gradually decreases from the point where the depth from the opening surface of the concave shape portion is deepest toward the apex, and the plurality of concave shape portions are adjacent to each other. The arrangement direction of the concave portions has an angle in the circumferential direction and the axial direction of the electrophotographic photosensitive member.

As a result of the study by the present inventors, specific concave portions are densely arranged on the surface of the electrophotographic photosensitive member, and the arrangement direction of the specific concave portions is given an angle in the circumferential direction and the axial direction. It has been found that the effect of suppressing streak-like image defects generated in a high-temperature and high-humidity environment is greatly improved.
By providing concave portions with a specific width at a high density on the surface of the electrophotographic photosensitive member, large torsion and vibration (vibration) in the longitudinal direction of the cleaning blade (the same direction as the axial direction of the electrophotographic photosensitive member) can be further increased. It is efficiently suppressed. As a result, even when the load is large on the cleaning blade, more stable rubbing is performed, so that the deterioration of the cleaning blade is reduced even when it is used for a long time.

Furthermore, the concave shape portion has an opening surface having a contour shape shown below.
The contour shape of the opening surface of the concave portion has two contour lines, two contour curves, or a vertex composed of one contour line and one contour curve on the rear end side in the rotation direction of the electrophotographic photosensitive member. . Further, the contour straight line or the contour curve that forms the vertex extends 2 in the circumferential direction of the electrophotographic photosensitive member on the contour straight line or the contour curve, and the distance to the straight line A that passes through the vertex is the longest 2 The distance to the straight line A gradually decreases from one point toward the vertex. Further, when the contour line or the contour curve is located on the contour line or the contour curve from the two points that are the farthest apart to the vertex, the contour line or the tangent of the contour curve is the electrophotographic image. The angle formed with respect to the axial direction of the photoreceptor is 45 ° or more and 90 ° or less.
In the case of a concave portion having a contour-shaped opening that satisfies these conditions, blade deformation and blade vibration associated with the cleaning blade passing through the rear end side in the rotation direction of the electrophotographic photosensitive member of the concave portion are suppressed. Is done. As a result, the behavior of the cleaning blade in the micro area is further uniformized. As a result, the uniformity of the rubbing state between the cleaning blade and the electrophotographic photosensitive member is dramatically improved, thereby suppressing memory generated due to deposits and non-uniform rubbing on the electrophotographic photosensitive member. The present inventors consider that the effect of suppressing / H initial streaks is manifested.

  Further, as the arrangement of the specific concave shape portion, by arranging the adjacent concave shape portion with an angle with respect to the circumferential direction and the axial direction, in other words, the plurality of concave shape portions can be arranged as adjacent concave shape portions. Since the arrangement direction has an angle with respect to the circumferential direction and the axial direction, the behavior of the cleaning blade is stabilized.

  Arranging a certain concave shape portion at an angle with respect to the circumferential direction of the adjacent concave shape portion means that the adjacent concave shape has a width (concave shape) of the concave shape portion with respect to the circumferential direction of the electrophotographic photosensitive member. It is shown that they are arranged so as to be shifted within a range shorter than the axial length of the portion. On the other hand, arranging a certain concave shape portion with an angle with respect to the adjacent concave shape portion is that the concave shape adjacent to the axial direction of the electrophotographic photosensitive member is the axial direction of the electrophotographic photosensitive member. On the other hand, it shows that it is shifted and arranged in a range shorter than the length of the concave portion (the circumferential length of the concave portion).

  A plurality of specific concave-shaped portions are arranged at an angle in the circumferential direction, so that the displacement amount of the micro area of the cleaning blade is dispersed, and against a change in the circumferential direction (rotation of the electrophotographic photosensitive member). The present inventors consider that the load of the cleaning blade can be distributed.

  A plurality of specific concave portions are arranged at an angle in the axial direction, so that the displacement timing in the macro area when the cleaning blade moves in the circumferential direction is dispersed, and the length of the cleaning blade The present inventors consider that a large twist or vibration in the direction (the axial direction of the electrophotographic photosensitive member) can be suppressed.

  Specifically, a plurality of independent concave portions are provided on the surface of the electrophotographic photosensitive member of the present invention, and the axial width of the opening surface of the concave portion is 20 μm. The contour shape of the opening of the concave portion is not less than 80 μm, and two contour straight lines, two contour curves, or one contour straight line is formed on at least one end side in the circumferential direction of the electrophotographic photosensitive member. And a contour curve, and the contour straight line or the contour curve forming the vertex extends in the circumferential direction of the electrophotographic photosensitive member on the contour straight line or the contour curve. The distance to the straight line A gradually decreases from the two points that are the most distant from the straight line A to the vertex, and from the two points that are the farthest to the vertex, The contour straight line or the tangent to the contour curve The angle formed with respect to the axial direction of the sub-photosensitive member is not less than 45 ° and not more than 90 °, and the concave portion has a depth from the deepest point to the apex from the opening surface of the concave portion. Gradually becomes shallower. (Hereinafter, the concave portion having the specific shape is also referred to as “specific concave portion”.)

In the present invention, the specific concave-shaped portion is located at any position on the surface of the electrophotographic photosensitive member when a square region having a side of 500 μm (area is 250,000 μm ² ) (that is, any position on the surface of the electrophotographic photosensitive member). In other words, a square area having a side of 500 μm is disposed on the surface of the electrophotographic photosensitive member so that the total area of the specific concave portions in the square area having a side of 500 μm is 100000 μm ² or more. Alternatively, in the present invention, the specific concave-shaped portion has a 500 μm square area (area: 250,000 μm ² ) arranged at an arbitrary position in the contact area with the cleaning blade on the surface of the electrophotographic photosensitive member (that is, electrophotography). So that the sum of the areas of the specific concave portions in the 500 μm square area is 100000 μm ² or more regardless of the position of the 500 μm side square area in any contact area of the surface of the photosensitive member with the cleaning blade. And provided on the surface of the electrophotographic photosensitive member. When the surface of the electrophotographic photosensitive member is a curved surface (for example, when the electrophotographic photosensitive member is cylindrical, the surface (circumferential surface) of the electrophotographic photosensitive member is a curved surface curved in the circumferential direction). , “Disposing a square region (area: 250,000 μm ² ) having a side of 500 μm at an arbitrary position on the surface of the electrophotographic photosensitive member” means a region that becomes a square in the plane when the curved surface is corrected to a plane ( This means that an area of 250,000 μm ² ) is arranged at an arbitrary position on the surface of the electrophotographic photosensitive member. Similarly, “arranging a square region (area: 250,000 μm ² ) having a side of 500 μm at an arbitrary position in the contact region with the cleaning blade on the surface of the electrophotographic photosensitive member” means that when the curved surface is corrected to a flat surface, It means that a region (area is 250,000 μm ² ) that becomes a square in the plane is arranged at an arbitrary position in the contact region with the cleaning blade on the surface of the electrophotographic photosensitive member.

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

As the laser microscope, for example, the following devices can be used.
Keyence's ultra-deep shape measuring microscope VK-8550, ultra-deep shape measuring microscope VK-9000, ultra-deep shape measuring microscope VK-9500, VK-X200, VK-X100 Scanning confocal made by Olympus Corporation Laser microscope OLS3000
Real color confocal microscope Oplitex C130 manufactured by Lasertec Co., Ltd.
As the optical microscope, for example, the following devices can be used.
Digital microscope VHX-500, digital microscope VHX-200 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.
Keyence 3D Real Surface View Microscope VE-9800, 3D Real Surface View Microscope VE-8800
Scanning Electron Microscope Conventional / Variable Pressure SEM manufactured by Hitachi High-Tech Science Co., Ltd. (formerly SII Nanotechnology 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.
KEYENCE nanoscale hybrid microscope VN-8000
Scanning probe microscope NanoNavi station manufactured by Hitachi High-Tech Science Co., Ltd. Scanning probe microscope SPM-9600 manufactured by Shimadzu Corporation

  The observation of the square area with a side of 500 μm may be performed at a magnification such that the square area with a side of 500 μm can be accommodated, or after partial observation at a higher magnification, a plurality of partial images are connected using software. You may make it do.

The specific concave shape portion in the square region having a side of 500 μm will be described below.
First, the surface of the electrophotographic photoreceptor is enlarged and observed with a microscope. For example, when the surface (circumferential surface) of the electrophotographic photosensitive member is a curved surface curved in the circumferential direction as in the case where the electrophotographic photosensitive member is cylindrical, a cross-sectional profile of the curved surface is extracted and a curved line ( If the electrophotographic photosensitive member is cylindrical, an arc) is fitted.

  FIG. 1 shows an example of fitting. The example shown in FIG. 1 is an example in which the electrophotographic photosensitive member is cylindrical, and is a part of the surface of the electrophotographic photosensitive member in a cross section perpendicular to the axial direction (cross section parallel to the circumferential direction). is there. In FIG. 1, a solid line 101 is a cross-sectional profile of the surface (curved surface) of the electrophotographic photosensitive member, and a broken line 102 is a curve fitted to the cross-sectional profile 101. The cross-sectional profile 101 is corrected so that the curve 102 becomes a straight line, and a surface obtained by extending the obtained straight line in the longitudinal direction (direction orthogonal to the circumferential direction, that is, the axial direction) of the electrophotographic photosensitive member is defined as a reference surface. To do. Even when the electrophotographic photosensitive member is not cylindrical, the reference surface is obtained in the same manner as when the electrophotographic photosensitive member is cylindrical.

A portion located below the obtained reference plane is defined as a concave portion in the square region. A cross section of the concave portion by the reference surface is an opening surface of the concave portion. The distance from the reference surface to the point farthest from the reference surface (opening surface) (the deepest point) of the bottom surface of the concave portion is the depth of the concave portion. Of the line segments crossing the opening surface in the axial direction, the length of the longest line segment is defined as the width of the opening surface of the concave portion. The width of the opening surface of the specific concave portion in the present invention is in the range of 20 μm or more and 80 μm or less from the viewpoint of stabilizing the cleaning blade and effectively reducing toner slipping and H / H initial streaks in a low temperature environment. It is preferable. Furthermore, it is more preferable that the width of the opening surface of the specific concave portion is in the range of 30 μm to 60 μm. Moreover, it is preferable that the sum total of the area of the opening surface of the specific concave-shaped part in the said square area | region is 100000 micrometers ² or more, and it is more preferable that they are 100000 micrometers ² or more and 175000 micrometers ² or less.

  Further, when the area of the opening surface of the specific concave shape portion was measured in each of the above-described square regions having a side of 500 μm arranged at any 50 locations on the surface of the electrophotographic photosensitive member, the opening surfaces of the 50 specific concave shape portions were measured. The standard deviation of the measured value of the total area is preferably 5% or less.

FIG. 2A shows an example of an opening surface of the specific concave shape portion (a top view of the specific concave shape portion), and FIG. 2B shows a circumferential cross section of the specific concave shape portion shown in FIG. Indicates. The example of the cross section of the specific concave portion shown in FIG. 2B is the cross-sectional profile after the correction.
3A to 3J show examples of the shape of the opening surface of the specific concave portion (the shape when the specific concave portion is viewed from above).
The example of the shape of the circumferential cross section of a specific concave shape part is shown to Fig.4 (a)-(h).

  An example of the specific concave shape portion shown in FIGS. 2A and 2B will be described. First, the shape of the opening surface of the specific concave portion will be described. The opening surface of the specific concave portion shown in FIG. 2 has a vertex I composed of two contour straight lines on one end side in the circumferential direction of the electrophotographic photosensitive member, and the other end side has a semicircular shape. doing. In addition, the opening surface is a circumferential line, and the distance to the straight line A passing through the vertex I is two points F and F ′ that are the farthest on the two contour straight lines (indicated by dotted lines with arrows from the straight line A). The position gradually decreases from the position) toward the vertex I.

In the specific concave shape portion of the present invention, the tangent line of the contour straight line or the contour curve between the two points F and F ′ on the contour straight line or contour curve farthest from the vertex I to the vertex I is electrophotographic photosensitive. it is preferable from the viewpoint of slipping and H / H initial streaks of toner angle theta ₁ which forms with respect to the axial direction of the body is 45 ° to 90 °. Furthermore, it is more preferred angle theta ₁ is less than 90 ° 62 ° or more.

Further, when projected from the opening surface of the specific concave shape portion, an angle formed by two contour straight lines between two points F and F ′ to the vertex I on the contour straight line or the contour curve with the longest distance, 2 one of the angle formed by the tangent of the contour curve, or the angle between one contour line and the tangent of one contour curve and theta _2. Here, the angle theta ₂ is at 58 ° or less is preferable from the viewpoint of slipping and H / H Initial streaks of toner. Furthermore, it is more preferred angle theta ₂ is at 56 ° or less.

Next, a circumferential section of the specific concave shape portion will be described. The circumferential cross section in an example of the specific concave shape portion shown in FIG. 2B has a depth from the deepest point D to the vertex I in the depth direction of the electrophotographic photosensitive member with respect to the opening surface of the concave shape portion. Has a shape that becomes linearly shallower, and the other (side facing away from the vertex I from the point D) has an arc shape. In the present invention, when the electrophotographic photosensitive member is projected from the side surface (when viewed from a direction parallel to the axial direction), the straight line on the opening surface of the specific concave portion, the vertex I, and the electrophotographic photosensitive member The angle θ ₃ formed by the straight line connecting the deepest point D in the depth direction is more preferably 8.5 ° or less from the viewpoint of slipping through the toner and H / H initial streaks. Furthermore, the angle θ ₃ is more preferably 3.8 ° or less.

Examples of the contour shape of the opening surface of the specific concave shape portion include shapes as shown in FIGS. When the vertical direction in FIG. 3 is the circumferential direction of the electrophotographic photosensitive member, among the contour shapes of the opening surface of the specific concave shape portion illustrated in FIG. 3, (C), (D), (F), (I) and (J) has a vertex on one end side in the circumferential direction, and (A), (B), (E), (G) and (H) have a vertex on both end sides in the circumferential direction. Shape.
Here, in the case of FIG. 3C, the upper end side in FIG. 3 among the circumferential ends of the electrophotographic photosensitive member is the axial direction of the electrophotographic photosensitive member (that is, the horizontal direction in FIG. 3). Consists of matching contour lines, and both ends of the contour line matching the axial direction are in contact with other contour lines. However, when the end in the circumferential direction is a straight line that coincides with the axial direction as in the upper end side in FIG. 3C, the end does not have a vertex in the present invention.

  Moreover, as a cross-sectional shape of a specific concave shape part, the shape as shown to Fig.4 (a)-(h) is mentioned, for example. Each of the cross-sectional shapes of the specific concave shape portion shown in FIG. 4 is a shape in which the depth gradually decreases from the point having the deepest depth from the opening surface toward the apex. Note that, as shown in FIG. 4C, the deepest point is not a single point but a continuous flat part (a line or surface parallel to the opening surface) is formed. However, it is included in the shape in which the depth gradually decreases from the point having the deepest depth from the opening surface to the apex in the present invention.

  The plurality of independent specific concave-shaped portions provided on the surface of the electrophotographic photosensitive member may all have the same shape (for example, the same opening surface longest diameter and depth) or different shapes (for example, Different ones with the longest diameter and depth of the opening surface may be mixed. Moreover, you may form concave shape parts other than the concave shape part which concerns on this invention as needed.

  The specific concave portion may be formed on the entire surface of the electrophotographic photosensitive member, or may be formed on a part of the surface of the electrophotographic photosensitive member. When the specific concave portion is formed on a part of the surface of the electrophotographic photosensitive member, it is preferable that the specific concave portion is formed at least in the entire contact area with the cleaning blade.

<Method of forming a concave portion on the surface of an electrophotographic photosensitive member>
An example of a method for forming a recess on the surface of the electrophotographic photosensitive member is a method in which a mold having a convex portion corresponding to the concave portion to be formed is pressed against the surface of the electrophotographic photosensitive member and shape transfer is performed. .

FIG. 5 shows an example of a press-contact shape transfer processing apparatus for forming a concave portion on the surface of the electrophotographic photosensitive member.
According to the press-contact shape transfer processing apparatus shown in FIG. 5, while rotating the electrophotographic photosensitive member 51 as a workpiece, the mold 52 is continuously brought into contact with the surface (circumferential surface) and pressurized, whereby the electronic A concave portion or a flat portion can be formed on the surface of the photoconductor 51.

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

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

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

  As the mold 52, for example, a metal or resin film that has been subjected to fine surface processing, a surface of a silicon wafer or the like patterned with a resist, a resin film in which fine particles are dispersed, and a resin film having a fine surface shape And the like coated with a metal coating.

  From the viewpoint of making the pressure pressed against the electrophotographic photoreceptor 51 uniform, it is preferable to install an elastic body (not shown) between the mold 52 and the pressing member 53.

<Configuration of electrophotographic photoreceptor>
The electrophotographic photoreceptor of the present invention has a support and a photosensitive layer formed on the support.
The photosensitive layer may be a single-layer type photosensitive layer containing a charge transport material and a charge generation material in the same layer, or a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material. It may be a laminated type (functionally separated type) photosensitive layer separated. From the viewpoint of electrophotographic characteristics, a laminated photosensitive layer is preferred. Further, the laminated photosensitive layer may be a normal photosensitive layer in which the charge generation layer and the charge transport layer are laminated in this order from the support side, or a reverse layer in which the charge transport layer and the charge generation layer are laminated in this order from the support side. Type photosensitive layer. From the viewpoint of electrophotographic characteristics, a normal layer type photosensitive layer is preferred. In addition, the charge generation layer may have a stacked structure, and the charge transport layer may have a stacked structure.

(Support)
The support is preferably one that exhibits conductivity (conductive support). Examples of the material of the support include metals (alloys) such as iron, copper, gold, silver, aluminum, zinc, titanium, lead, nickel, tin, antimony, indium, chromium, aluminum alloy, and stainless steel. In addition, a metal support or a plastic support having a film formed by vacuum deposition using aluminum, an aluminum alloy, an indium oxide-tin oxide alloy, or the like can also be used. In addition, a support obtained by impregnating plastic or paper with conductive particles such as carbon black, tin oxide particles, titanium oxide particles, and silver particles, or a support made of conductive binder resin can also be used.

  The surface of the support may be subjected to cutting treatment, roughening treatment, anodizing treatment, etc. for the purpose of suppressing interference fringes due to scattering of laser light.

(Conductive layer)
Conduction between the support and the undercoat layer or photosensitive layer (charge generation layer, charge transport layer), which will be described later, for the purpose of suppressing interference fringes due to scattering of laser light and covering scratches on the support. A layer may be provided.

  The conductive layer is formed by applying a coating solution for conductive layer obtained by dispersing carbon black, conductive pigment, resistance adjusting pigment and the like together with a binder resin to form a coating film, and then drying the obtained coating film. Can be formed. Moreover, you may add to the coating liquid for conductive layers the compound which carries out hardening polymerization by heating, ultraviolet irradiation, radiation irradiation, etc. A conductive layer in which a conductive pigment, a resistance adjusting pigment or the like is dispersed tends to have a roughened surface.

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

  Examples of the conductive pigment and the resistance adjusting pigment include particles of metals (alloys) such as aluminum, zinc, copper, chromium, nickel, silver, and stainless steel, and those obtained by depositing these on the surface of plastic particles. . It is also possible to use metal oxide particles such as zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin-doped indium oxide, antimony or tantalum-doped tin oxide. it can. These may be used alone or in combination of two or more. When two or more types are used in combination, they may be mixed, or may be in the form of a solid solution or fusion.

  The thickness of the conductive layer is preferably 0.2 μm or more and 40 μm or less, more preferably 1 μm or more and 35 μm or less, and more preferably 5 μm or more and 30 μm or less.

(Undercoat layer (intermediate layer))
Between the support or conductive layer and the photosensitive layer (charge generation layer, charge transport layer), improvement of adhesion of the photosensitive layer, improvement of coating property, improvement of charge injection from the support, electrical breakdown of the photosensitive layer An undercoat layer (intermediate layer) having a barrier function or an adhesive function may be provided for the purpose of protecting the film.
The undercoat layer can be formed by applying a coating solution for an undercoat layer obtained by dissolving a resin (binder resin) in a solvent and drying the obtained coating film.
Examples of the resin used for the undercoat layer include polyvinyl alcohol, poly-N-vinylimidazole, polyethylene oxide, ethyl cellulose, ethylene-acrylic acid copolymer, casein, polyamide, N-methoxymethylated 6 nylon, and copolymer nylon. , Glue, gelatin, polyurethane resin, acrylic resin, allyl resin, alkyd resin, phenol resin, epoxy resin and the like.

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

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

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

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

  Examples of the charge transport material used in the photosensitive layer include pyrene compounds, N-alkylcarbazole compounds, hydrazone compounds, N, N-dialkylaniline compounds, diphenylamine compounds, triphenylamine compounds, triphenylmethane compounds, pyrazoline compounds, styryl. Compounds and stilbene compounds. These charge transport materials may be used alone or in combination of two or more.

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

  The charge transport layer is formed by applying a charge transport layer coating solution obtained by dissolving a charge transport material and a binder resin in a solvent to form a coating film, and then drying the obtained coating film. Can do. In addition, in the case where a charge transport material having film-forming properties is used alone, the charge transport layer can be formed without using a binder resin.

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

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

  When the photosensitive layer is a single-layer type photosensitive layer, the photosensitive layer is formed by applying a photosensitive layer coating solution obtained by dissolving a charge generating substance, a charge transporting substance and a binder resin in a solvent to form a coating film. It can be formed by drying the obtained coating film. The same binder resin, charge generating substance and charge transporting substance used for the single layer type photosensitive layer can be used for the charge generating layer and the charge transporting layer.

Further, from the viewpoint of improving the durability of the electrophotographic photosensitive member, the surface layer of the electrophotographic photosensitive member is preferably composed of a crosslinked organic polymer.
In the present invention, for example, the charge transport layer on the charge generation layer can be composed of a crosslinked organic polymer as the surface layer of the electrophotographic photoreceptor. Further, a surface layer made of a crosslinked organic polymer can be formed on the charge transport layer on the charge generation layer as a second charge transport layer or a protective layer.

In addition, the characteristics required for the surface layer composed of the crosslinked organic polymer are both the strength of the film and the charge transport capability. From this viewpoint, the charge transport material or the conductive particles and the crosslinkable monomer / It is preferable to form a surface layer using an oligomer.
As the charge transport material, the above-described charge transport materials can be used. Moreover, well-known electroconductive particle can be used as electroconductive particle. Examples of the crosslinkable monomer / oligomer include a compound having a chain polymerizable functional group such as an acryloyloxy group and a styryl group, and a compound having a sequentially polymerizable functional group such as a hydroxyl group, an alkoxysilyl group and an isocyanate group. Can be mentioned.
Further, from the viewpoint of achieving both the strength of the film and the charge transport capability, it is more preferable to use a compound having both a charge transport structure (preferably a hole transport structure) and an acryloyloxy group in the same molecule.
Examples of the crosslinking and curing method include a method using heat, ultraviolet rays, and radiation.
The film thickness of the surface layer composed of the crosslinked organic polymer is preferably 0.1 to 30 μm, and more preferably 1 to 10 μm.

  Additives can be added to each layer of the electrophotographic photoreceptor. Examples of additives include deterioration inhibitors such as antioxidants and ultraviolet absorbers, organic resin particles such as fluorine atom-containing resin particles and acrylic resin particles, and inorganic particles such as silica, titanium oxide, and alumina. It is done.

<Configuration of process cartridge and electrophotographic apparatus>
FIG. 6 shows an example of an electrophotographic apparatus provided with a process cartridge having the electrophotographic photosensitive member of the present invention.
In FIG. 6, a cylindrical electrophotographic photosensitive member 1 of the present invention is driven to rotate around a shaft 2 at a predetermined peripheral speed (process speed) in the direction of an arrow. The surface of the electrophotographic photosensitive member 1 is uniformly charged to a predetermined positive or negative potential by a charging unit 3 (primary charging unit: for example, a charging roller) during the rotation process. Next, the uniformly charged surface of the electrophotographic photosensitive member 1 receives exposure light (image exposure light) 4 irradiated from an exposure means (image exposure means) (not shown). In this way, an electrostatic latent image corresponding to target image information is formed on the surface of the electrophotographic photosensitive member 1. Note that the rotation direction of the electrophotographic photosensitive member 1 coincides with one of the circumferential directions of the electrophotographic photosensitive member 1. The electrophotographic photosensitive member 1 can be rotated in any of the circumferential directions, and is mounted on the electrophotographic apparatus and rotated in a predetermined direction.
The present invention is particularly effective when a charging means using discharge is used.

  The electrostatic latent image formed on the surface of the electrophotographic photoreceptor 1 is then developed (regular development or reversal development) with toner (indeterminate toner or spherical toner) in the developing means 5 to form a toner image. A toner image formed on the surface of the electrophotographic photosensitive member 1 is transferred onto a transfer material by a transfer bias from a transfer unit (for example, a transfer roller) 6. At this time, the transfer material P is taken out from the transfer material supply means (not shown) in synchronism with the rotation of the electrophotographic photosensitive member 1 and is placed between the electrophotographic photosensitive member 1 and the transfer means 6 (contact portion). Be fed. Further, a bias voltage having a polarity opposite to the charge held in the toner is applied to the transfer unit 6 from a bias power source (not shown).

  The transfer material P to which the toner image has been transferred is separated from the surface of the electrophotographic photosensitive member 1 and conveyed to the fixing means 8 to undergo the toner image fixing process, whereby an electrophotographic image forming product (print, copy) is obtained. Printed out of the device.

  The surface of the electrophotographic photoreceptor 1 after the transfer of the toner image is subjected to removal of deposits such as transfer residual toner by a cleaning means 7 having a cleaning blade placed in contact (contact) with the surface of the electrophotographic photoreceptor 1. To clean the surface. Further, the cleaned surface of the electrophotographic photoreceptor 1 is subjected to charge removal processing by pre-exposure light (not shown) from a pre-exposure means (not shown), and then repeatedly used for image formation. As shown in FIG. 6, when the charging unit 3 is a contact charging unit using a charging roller or the like, the pre-exposure unit is not necessarily required.

  The process cartridge according to the present invention is a process cartridge having at least the electrophotographic photosensitive member 1 and a cleaning blade. In the present invention, the electrophotographic photosensitive member 1, the cleaning blade, and one or more components selected from the components selected from the charging unit 3 and the developing unit 5 are housed in a container and integrated as a process cartridge. It is good also as a structure supported by. The process cartridge can be configured to be detachable from a main body of an electrophotographic apparatus such as a copying machine or a laser beam printer. In FIG. 6, the electrophotographic photosensitive member 1, the charging unit 3, the developing unit 5, and the cleaning unit 7 having a cleaning blade are integrally supported to form a cartridge, and guide units such as a rail of the electrophotographic apparatus main body. 10 is used as a process cartridge 9 detachably attached to the main body of the electrophotographic apparatus.

  When the electrophotographic apparatus is a copying machine or a printer, the exposure light 4 is a reflected light or transmitted light from a manuscript, or a manuscript is read by a sensor, converted into a signal, laser beam scanning performed in accordance with this signal, LED array, Light emitted by driving a liquid crystal shutter array or the like.

  Hereinafter, the present invention will be described in more detail with reference to specific examples. In the examples, “part” means “part by mass”. Further, the electrophotographic photoreceptor is hereinafter simply referred to as “photoreceptor”.

(Example of photoconductor-1 production)
An aluminum cylinder having a diameter of 30 mm and a length of 357.5 mm was used as a support (cylindrical support).
Next, 100 parts of zinc oxide particles (specific surface area: 19 m ² / g, powder resistance: 4.7 × 10 ⁶ Ω · cm) as a metal oxide are stirred and mixed with 500 parts of toluene, and this is mixed with a silane coupling agent. (Compound name: N-2- (aminoethyl) -3-aminopropylmethyldimethoxysilane, trade name: KBM602, manufactured by Shin-Etsu Chemical Co., Ltd.) 0.8 part was added and stirred for 6 hours. Thereafter, toluene was distilled off under reduced pressure, followed by heating and drying at 130 ° C. for 6 hours to obtain surface-treated zinc oxide particles.

Next, 15 parts of butyral resin (trade name: BM-1, manufactured by Sekisui Chemical Co., Ltd.) and blocked isocyanate (trade name: Sumidur 3175, Sumika Covestro Urethane Co., Ltd. (former: Sumitomo Bayer Urethane) as polyol resin 15 parts) was dissolved in a mixed solution of 73.5 parts of methyl ethyl ketone and 73.5 parts of 1-butanol. To this solution, 80.8 parts of the surface-treated zinc oxide particles and 0.8 part of 2,3,4-trihydroxybenzophenone (manufactured by Tokyo Chemical Industry Co., Ltd.) were added, and this was added to a glass having a diameter of 0.8 mm. Dispersion was performed in a sand mill apparatus using beads in an atmosphere of 23 ± 3 ° C. for 3 hours. After dispersion, 0.01 parts of silicone oil (trade name: SH28PA, manufactured by Toray Dow Corning Silicone), cross-linked polymethyl methacrylate (PMMA) particles (trade name: TECHPOLYMER SSX-102, manufactured by Sekisui Plastics Co., Ltd.) 5.6 parts of an average primary particle size of 2.5 μm) was added and stirred to prepare an undercoat layer coating solution.
This undercoat layer coating solution was applied onto the support by dip coating, and the resulting coating film was dried at 160 ° C. for 40 minutes to form an undercoat layer having a thickness of 18 μm.

Next, 20 parts of a crystalline hydroxygallium phthalocyanine crystal (charge generation material) having strong peaks at 7.4 ° and 28.2 ° with a Bragg angle 2θ ± 0.2 ° in CuKα characteristic X-ray diffraction, the following structural formula A glass bead having a diameter of 1 mm was used for 0.2 part of the calixarene compound represented by (A), 10 parts of polyvinyl butyral (trade name: ESREC BX-1, manufactured by Sekisui Chemical Co., Ltd.) and 600 parts of cyclohexanone. After putting into a sand mill and dispersing for 4 hours, 700 parts of ethyl acetate was added to prepare a charge generation layer coating solution. The charge generation layer coating solution was dip-coated on the undercoat layer, and the resulting coating film was dried at 80 ° C. for 15 minutes to form a charge generation layer having a thickness of 0.17 μm.

Next, 30 parts of a compound represented by the following structural formula (B) (charge transporting substance), 60 parts of a compound represented by the following structural formula (C) (charge transporting substance), and 10 of a compound represented by the following structural formula (D) Part, polycarbonate resin (trade name: Iupilon Z400, manufactured by Mitsubishi Engineering Plastics Co., Ltd., bisphenol Z type polycarbonate), polycarbonate having the following structural formula (E) (viscosity average molecular weight Mv: 20000) 0.02 part Was dissolved in a mixed solvent of 600 parts of mixed xylene and 200 parts of dimethoxymethane to prepare a coating solution for charge transport layer. The charge transport layer coating solution was dip coated on the charge generation layer to form a coating film, and the resulting coating film was dried at 100 ° C. for 30 minutes to form a charge transport layer having a thickness of 18 μm. .

Next, 36 parts of a compound represented by the following structural formula (F) (charge transporting substance having an acrylic group which is a chain polymerizable functional group), polytetrafluoroethylene resin fine powder (Lublon L-2, Daikin Industries, Ltd.) A protective layer coating solution was prepared by dispersing and mixing 4 parts) and 60 parts of n-propanol with an ultrahigh pressure disperser. This protective layer coating solution was dip-coated on the charge transport layer, and the resulting coating film was dried at 50 ° C. for 5 minutes. After drying, the coating film was cured by irradiating the coating film with an electron beam for 1.6 seconds under the conditions of an acceleration voltage of 70 kV and an absorbed dose of 8000 Gy in a nitrogen atmosphere. Thereafter, heat treatment was performed for 3 minutes in a nitrogen atmosphere under conditions where the coating film became 120 ° C. Note that the oxygen concentration from the electron beam irradiation to the heat treatment for 3 minutes was 20 ppm. Next, in the atmosphere, a heat treatment was performed for 30 minutes under the condition that the coating film reached 100 ° C., thereby forming a protective layer (second charge transport layer) having a thickness of 5 μm.

  In this way, a cylindrical electrophotographic photosensitive member (electrophotographic photosensitive member before forming the concave portion) before forming the concave portion on the surface was produced.

Forming a concave portion by mold press-fitting shape transfer A press-fitting shape transfer processing apparatus having a configuration shown in FIG. 5 is generally used as a mold with a mold having a shape shown in FIG. 16 (in this embodiment, a maximum width (a convex portion on the mold). Is the maximum width in the direction corresponding to the axial direction of the electrophotographic photosensitive member when viewed from above. The same applies hereinafter.) X: 40 μm, maximum length (electrophotography when the convex part on the mold is viewed from above) The maximum length in the direction corresponding to the circumferential direction of the photoreceptor, the same applies hereinafter.) Y: convex shape with 80 μm, area ratio 50%, height H: 4 μm) Surface processing was performed on the electrophotographic photosensitive member. The area ratio is the ratio of the total area of the areas where the protrusions on the mold are provided to the area of the processing area of the mold (that is, the area of the opening surface of the recess shape relative to the surface area of the peripheral surface of the electrophotographic photosensitive member). The ratio of the sum). At the time of processing, the temperature of the electrophotographic photosensitive member and the mold is controlled so that the surface temperature of the electrophotographic photosensitive member becomes 120 ° C., and the electrophotographic photosensitive member and the pressure member are pressed at a pressure of 7.0 MPa, The photosensitive member was rotated in the circumferential direction to form a concave portion on the entire surface (circumferential surface) of the electrophotographic photosensitive member.
Thus, an electrophotographic photosensitive member having a specific concave portion on the surface was produced. This electrophotographic photosensitive member is referred to as “photosensitive member-1”.

-Observation of the surface of the electrophotographic photosensitive member The surface of the obtained electrophotographic photosensitive member (photosensitive member-1) was magnified and observed with a 50 × lens with a laser microscope (trade name: X-100, manufactured by Keyence Corporation). The specific concave portion provided on the surface of the electrophotographic photosensitive member was determined as described above. At the time of observation, adjustment was performed so that there is no inclination in the longitudinal direction (axial direction) of the electrophotographic photosensitive member, and the circumferential direction was focused on the apex of the arc of the electrophotographic photosensitive member. A square region having a side of 500 μm was obtained by connecting the enlarged images with an image connection application. Moreover, about the obtained result, image processing height data was selected with attached image analysis software, and the filter process was performed by the filter type median.
By the above observation, the depth of the specific concave shape portion, the axial width of the opening surface, the length in the circumferential direction of the opening surface, the area, the angle of the apex formed by the two contour straight lines, and the like were obtained. The results are shown in Table 2.

  The surface of the electrophotographic photosensitive member (photosensitive member-1) was observed in the same manner as described above using another laser microscope (manufactured by Keyence Co., Ltd., trade name: X-9500). The same result as that obtained when using a laser microscope (trade name: X-100, manufactured by Keyence Corporation) was obtained. In the following production examples, a laser microscope (manufactured by Keyence Corporation, trade name: X-100) and a 50 × lens were used for observing the surface of the electrophotographic photosensitive member (photosensitive member-2 to 21).

(Production example of photoconductor-2 to photoconductor-21)
An electrophotographic photosensitive member was manufactured in the same manner as in the manufacturing example of the photosensitive member-1, except that the mold was changed as shown in Table 1 in the manufacturing example of the photosensitive member-1. These electrophotographic photosensitive members are referred to as “photosensitive member-2 to photosensitive member 21”. The surface of the obtained electrophotographic photoreceptor was observed in the same manner as in the production example of photoreceptor-1. The results are shown in Table 2.
7 to 18, (a) is a schematic top view showing a mold used in each example of production of an electrophotographic photosensitive member, and (b) is a protrusion in the mold shown in (a). BB schematic sectional drawing of a part, (c) A figure is CC schematic sectional drawing of the convex part in the mold shown by (a) figure. The photosensitive member-1 to the photosensitive member-4 use the mold shown in FIG. 16, the photosensitive member-5 to the photosensitive member-8 uses the mold shown in FIG. 17, and the photosensitive member-9 to the photosensitive member-12 use the mold shown in FIG. 16 to 18 are not shown in detail, and the maximum width X, the maximum length Y, the area ratio, and the height H are adjusted to those described in Table 1 according to each production example. Different molds are used.

(Evaluation of actual electrophotographic photosensitive member)
Example 1
Photoreceptor-1 is mounted on a cyan station of a modified machine of an electrophotographic apparatus (copier) (trade name: iR-ADV C5255) manufactured by Canon Inc., which is an evaluation apparatus, and tested and evaluated as follows. went.
Under the environment of 32.5 ° C / 85% RH, the conditions of the charging device and the image exposure device are set so that the dark portion potential (Vd) of the electrophotographic photosensitive member is -500V and the light portion potential (Vl) is -180V. The initial potential of the electrophotographic photosensitive member was adjusted.

  Next, a polyurethane rubber cleaning blade having a hardness of 77 ° was set so that the contact angle was 28 ° and the contact pressure was 50 g / cm with respect to the surface of the electrophotographic photosensitive member. With the heater (drum heater) for the electrophotographic photosensitive member turned on, 100 evaluation charts of 1% printed image next to A4 were output continuously in an environment of 32.5 ° C./85% RH. A screen image with a cyan density of 30% was output as a halftone image, and the H / H initial streak on the image was evaluated as follows. The results are shown in Table 3. This evaluation method is an accelerated evaluation, and was applied for the purpose of conspicuous difference in image quality. In the present invention, the hardness (IRHD) of a urethane rubber cleaning blade (urethane rubber) is measured by an international rubber hardness test M method using a Wallace microhardness meter manufactured by H. WALLACE. It is the value. The international rubber hardness test M method is defined in JIS K6253-1997.

A: No streak is generated on the image.
B: An image where a streak is suspected is obtained on the image, but it is a level at which it cannot be clearly determined whether or not it is a streak.
C: Slightly slight streaks can be confirmed on the image, but there is no problem on the image.
D: Although very slight streaks are generated on the image, it is at a level with no problem on the image.
E: Although slight streaks are generated on the image, the level is acceptable on the image.
F: A clear streak is generated on the image. This is an unacceptable level on the image.

(Examples 2-4, 9-12)
The actual evaluation of the electrophotographic photosensitive member was performed in the same manner as in Example 1 except that the electrophotographic photosensitive member shown in Table 3 was used. The results are shown in Table 3.

(Examples 5 to 8)
The electrophotographic photosensitive member shown in Table 3 was used, and the electrophotographic photosensitive member was mounted on the electrophotographic apparatus in a direction having a vertex on the rear end side in the rotation direction of the electrophotographic photosensitive member. In the same manner as in Example 1, the H / H initial stripe evaluation of the electrophotographic photosensitive member was performed. The results are shown in Table 3.

(Comparative Examples 1, 3-7, 9)
The actual evaluation of the electrophotographic photosensitive member was performed in the same manner as in Example 1 except that the electrophotographic photosensitive member shown in Table 3 was used. The results are shown in Table 3.

(Comparative Examples 2 and 8)
The electrophotographic photosensitive member shown in Table 3 was used, and the electrophotographic photosensitive member was mounted on the electrophotographic apparatus in a direction having a vertex on the rear end side in the rotation direction of the electrophotographic photosensitive member. In the same manner as in Example 1, the H / H initial stripe evaluation of the electrophotographic photosensitive member was performed. The results are shown in Table 3.

DESCRIPTION OF SYMBOLS 1 Electrophotographic photoreceptor, 2 axis | shaft, 3 charging means, 4 exposure light, 5 image development means, 6 transfer means, 7 cleaning means, 8 fixing means, 9 process cartridge, 10 guide means, 51 electrophotographic photoreceptor, 52 mold, 53 Pressure member, 54 Support member, 101 Cross-sectional profile (solid line), 102 Fitted curve (dashed line), A straight line, C vertex

Claims (8)

An electrophotographic photosensitive member having a photosensitive layer on a cylindrical support,
The surface of the electrophotographic photosensitive member has a plurality of independent concave portions,
The axial width of the electrophotographic photoreceptor of the opening of the concave portion is 20 μm or more and 80 μm or less,
When a square region having a side of 500 μm is arranged at an arbitrary position on the surface of the electrophotographic photosensitive member, the total area of the opening surfaces of the concave portions in the square region having a side of 500 μm is 100,000 μm ² or more,
The contour shape of the opening surface of the concave-shaped portion has two contour lines, two contour curves, or one contour line and one contour curve on at least one end side in the circumferential direction of the electrophotographic photosensitive member. Have vertices consisting of
The contour straight line or the contour curve forming the vertex is on the contour straight line or the contour curve.
The distance to the straight line A gradually decreases from the two points that extend in the circumferential direction of the electrophotographic photosensitive member and the farthest distance to the straight line A passing through the vertex toward the vertex,
The angle formed by the contour straight line or the tangent of the contour curve with respect to the axial direction of the electrophotographic photosensitive member from the two points that are the farthest apart to the vertex is 45 ° or more and 90 ° or less,
The concave shape portion is a shape in which the depth gradually decreases from the point where the depth from the opening surface of the concave shape portion is deepest toward the apex,
The electrophotographic photosensitive member, wherein the plurality of concave-shaped portions have an arrangement direction of adjacent concave-shaped portions having an angle with respect to a circumferential direction and an axial direction of the electrophotographic photosensitive member.   When the electrophotographic photosensitive member is projected from a side surface, an angle formed by a straight line on the opening surface of the concave portion and a straight line connecting the vertex and the deepest point in the depth direction of the electrophotographic photosensitive member is The electrophotographic photosensitive member according to claim 1, having an angle of 8.5 ° or less.   When projected from the opening surface of the concave-shaped portion, the angle formed by the two contour straight lines, the angle formed by the tangent lines of the two contour curves, or the above-mentioned 1 The electrophotographic photosensitive member according to claim 1 or 2, wherein an angle formed by one contour line and a tangent line of the one contour curve is 58 ° or less. A process cartridge having at least an electrophotographic photosensitive member having a photosensitive layer on a cylindrical support and a cleaning blade,
The surface of the electrophotographic photosensitive member has a plurality of independent concave portions,
The axial width of the electrophotographic photoreceptor of the opening of the concave portion is 20 μm or more and 80 μm or less,
When a square region having a side of 500 μm is arranged at an arbitrary position in the contact region with the cleaning blade on the surface of the electrophotographic photosensitive member, the total area of the opening surfaces of the concave portions in the square region having a side of 500 μm is 100,000 μm. ² or more,
The contour shape of the opening surface of the concave-shaped portion has two contour straight lines, two contour curves, or one contour straight line and one contour curve on the rear end side in the rotation direction of the electrophotographic photosensitive member. Have
The contour straight line or the contour curve forming the vertex is on the contour straight line or the contour curve.
The distance to the straight line A gradually decreases from the two points that extend in the circumferential direction of the electrophotographic photosensitive member and the farthest distance to the straight line A passing through the vertex toward the vertex,
The angle formed by the contour straight line or the tangent of the contour curve with respect to the axial direction of the electrophotographic photosensitive member from the two points that are the farthest apart to the vertex is 45 ° or more and 90 ° or less,
The process cartridge according to claim 1, wherein the plurality of concave-shaped portions have an arrangement direction of adjacent concave-shaped portions having an angle with respect to a circumferential direction and an axial direction of the electrophotographic photosensitive member.   When projected from the opening surface of the concave-shaped portion, the angle formed by the two contour straight lines, the angle formed by the tangent lines of the two contour curves, or the above-mentioned 1 The process cartridge according to claim 4, wherein an angle formed by one contour line and a tangent line of the one contour curve is 58 ° or less.   6. The process cartridge according to claim 4, wherein the concave shape portion has a shape in which the depth gradually decreases from a point having the deepest depth from the opening surface of the concave shape portion toward the apex.   When the electrophotographic photosensitive member is projected from a side surface, an angle formed by a straight line on the opening surface of the concave portion and a straight line connecting the vertex and the deepest point in the depth direction of the electrophotographic photosensitive member is The process cartridge according to claim 6, which is 8.5 ° or less.   The electrophotographic photosensitive member according to any one of claims 1 to 3, charging means for charging the surface of the electrophotographic photosensitive member, and electrostatic charging by irradiating the charged surface of the electrophotographic photosensitive member with exposure light. Exposure means for forming a latent image, developing means for developing the electrophotographic photosensitive member on which the electrostatic latent image is formed with toner, transfer means for transferring the toner image on the electrophotographic photosensitive member onto a transfer material, and An electrophotographic apparatus comprising: a cleaning blade disposed in contact with the electrophotographic photosensitive member.

Images