JP2009031572A - Electrophotographic photoreceptor, process cartridge, and electrophotographic device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic photoreceptor in which high uniformity of an electrostatic latent image can be obtained between the start side of coating and the end side of coating of a photosensitive layer without depending only on changing the deposition quantity of a charge generating material. <P>SOLUTION: A layered type electrophotographic photoreceptor is provided, which includes a base layer comprising at least either a conductive layer or an intermediate layer or both layers and a photosensitive layer on a support, and a photosensitive layer formed by a dip coating method. The surface of the base layer has a plurality of recessed portions each independent from others, in which the major axial diameter (Rpc) of the surface aperture of each recessed portion is not more than 30 μm, while the minor axial diameter (Lpc) of the surface aperture of each recessed portion is not less than 1.0 μm, and the distance between the deepest portion of the recessed portion and the aperture face is gradually increased from recessed portions formed in the start side of coating toward recessed portions formed in the end side of coating. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an electrophotographic photosensitive member, and a process cartridge and an electrophotographic apparatus having 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 has a so-called laminated type photosensitive layer formed by laminating a charge transport layer. This takes into account the advantages of high sensitivity and material design diversity. Also, as a production method, a dip coating method is often used from the same advantages of low cost and high productivity.

  In addition, demands for higher speed and higher image quality of electrophotographic apparatuses are further increasing, and in particular, halftone images and solid images are often output due to colorization (full color) of output images. The demand for higher quality is increasing year by year.

  Under such circumstances, the electrostatic latent image on the photoreceptor is required to have high uniformity, but in the photoreceptor prepared by the dip coating method, there is a difference in sensitivity between the coating start side and the coating end side. There was a problem that occurred.

  With respect to this problem, a technique (see Patent Documents 1 and 2) for producing a photoreceptor in which the amount of charge generation material constituting the charge generation layer is inclined has been proposed.

However, if the adhesion amount is excessively increased, there are cases where adverse effects such as an increase in residual potential due to durability and deterioration of ghosts may occur. Further, if the amount of adhesion is too small, streaky coating unevenness may easily occur depending on the coating conditions. As described above, there is a problem in achieving uniformity by inclining the adhesion amount of the charge generation material.
Japanese Patent No. 3728952 Japanese Patent No. 3871848

  The present invention has been made in view of the above-described problem, and does not depend only on inclining the amount of charge generation material deposited, but has a high electrostatic latent image between the coating start side and the coating end side. An object of the present invention is to provide an electrophotographic photoreceptor capable of obtaining uniformity. Another object of the present invention is to provide a process cartridge and an electrophotographic apparatus having such an electrophotographic photosensitive member.

  As a result of intensive studies, the present inventors have arranged a fine concave portion on the surface of the underlayer of the electrophotographic photosensitive member so as to satisfy a certain condition, thereby reducing static between the coating start side and the coating end side. It has been found that high uniformity of the electrostatic latent image can be achieved, and the present invention has been made.

  That is, the electrophotographic photoreceptor according to the present invention has on the support a base layer composed of at least one of or both of a conductive layer and an intermediate layer, and a photosensitive layer, and the photosensitive layer is formed by a dip coating method. In the multilayer electrophotographic photoreceptor, the surface of the underlayer has a plurality of independent concave portions, and the major axis diameter (Rpc) of each surface opening portion of the concave portion is 30 μm or less, the short axis diameter (Lpc) of each surface opening portion of the concave portion is 1.0 μm or more, and the distance (Rdv) between the deepest portion of the concave portion and the opening surface Is gradually increased from the concave portion formed on the coating start side toward the concave portion formed on the coating end side.

  The process cartridge according to the present invention integrally supports the above-described electrophotographic photosensitive member and at least one means selected from the group consisting of a charging means, a developing means, and a cleaning means, and is attached to and detached from the main body of the electrophotographic apparatus. It is characterized by being free.

  Furthermore, an electrophotographic apparatus according to the present invention includes the above-described electrophotographic photosensitive member, and a charging unit, an exposing unit, a developing unit, and a transfer unit.

  According to the present invention, high uniformity of the electrostatic latent image can be achieved between the coating start side and the coating end side.

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

  As described above, the electrophotographic photoreceptor according to the present invention has a base layer composed of at least one of or both of a conductive layer and an intermediate layer and a photosensitive layer on the support, and forms the photosensitive layer by a dip coating method. This is a laminated electrophotographic photosensitive member. In the electrophotographic photosensitive member according to the present invention, the surface of the underlayer has a plurality of independent concave portions. In the electrophotographic photosensitive member according to the present invention, the major axis diameter (Rpc) of each surface opening portion of the plurality of concave portions is not more than 30 μm, and each surface opening of the plurality of concave portions is The minor axis diameter (Lpc) of the part is 1.0 μm or more. If the major axis diameter (Rpc) is larger than this range, coating defects in the charge generation layer are likely to occur. If the minor axis diameter (Lpc) is smaller than this range, sufficient effects may not be exhibited depending on the coating conditions of the photosensitive layer. In the electrophotographic photoreceptor according to the present invention, the distance (Rdv) between the deepest portion of the concave portion and the aperture surface is a concave formed on the dip coating end side from the concave shape portion formed on the dip coating start side. It is characterized by gradually increasing toward the shape part.

  In the electrophotographic photosensitive member according to the present invention, each of the plurality of independent concave portions indicates a state in which each concave portion is clearly separated from other concave portions.

  The shape of the concave portion formed on the surface of the electrophotographic photosensitive member according to the present invention is not particularly limited in the observation of the surface of the photosensitive member, for example, a shape constituted by a straight line, a shape constituted by a curve, or The shape comprised by a straight line and a curve is mentioned. Examples of the shape in which the concave portion is configured by a straight line include a triangle, a quadrangle, a pentagon, and a hexagon. Examples of the shape in which the concave portion is configured by a curve include a circular shape or an elliptical shape. Examples of the shape in which the concave portion is configured by a straight line and a curve include a square with a rounded corner, a hexagon with a rounded corner, and a sector.

  In addition, the shape of the concave portion formed on the surface of the electrophotographic photosensitive member according to the present invention is not particularly limited in the observation of the cross section of the photosensitive member. Or a shape constituted by a straight line and a curved line. Examples of the shape constituted by the straight line include a triangle, a quadrangle, and a pentagon. Examples of the shape constituted by this curve include a partial circular shape or a partial elliptical shape. Examples of the shape constituted by the straight line and the curve include a quadrangular shape or a sector shape with rounded corners.

  Specific examples of the concave portion on the surface of the electrophotographic photoreceptor according to the present invention include the concave portion shown in FIGS. FIG. 1 is a diagram illustrating an example of a surface shape of a concave portion in the present invention, and an arrow in the drawing indicates a major axis diameter (Rpc) in the concave portion. FIG. 2 is a diagram illustrating an example of the surface shape of the concave portion in the present invention, and an arrow in the drawing indicates a short axis diameter (Lpc) in the concave portion. FIG. 3 is a diagram showing an example of the cross-sectional shape of the concave portion in the present invention, and the arrows in the figure indicate the major axis diameter (Rpc) and the distance (Rdv) between the deepest portion and the aperture surface in the concave portion. ).

  The plurality of concave portions formed on the surface of the electrophotographic photosensitive member according to the present invention may have different shapes, sizes, or depths, and all the concave portions have the same shape and size. Or depth. Furthermore, the surface of the electrophotographic photosensitive member according to the present invention is a surface in which concave portions having different shapes, sizes, or depths and concave portions having the same shape, size, or depth are combined. It may be.

  In the electrophotographic photosensitive member according to the present invention, the major axis diameter (Rpc) of the concave portion refers to the length of the maximum straight line among the straight lines crossing the opening of each concave portion. 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 aperture part of the concave part is used as a reference. This is the length when the distance between the two straight lines becomes the maximum when the concave part is sandwiched between two parallel straight lines in contact with the end of the part. For example, when the surface shape of the concave shape portion is circular, it indicates the diameter, when the surface shape of the concave shape portion is elliptical, it indicates the long diameter, and when the surface shape of the concave shape portion is a square, the diagonal line Long diagonal lines are shown.

  In the electrophotographic photosensitive member according to the present invention, the minor axis diameter (Lpc) of the concave-shaped portion refers to the length of the minimum straight line among the straight lines crossing the opening of each concave-shaped portion. Specifically, as shown by the short axis diameter (Lpc) in FIG. 2, the two parallel parallel surfaces that are in contact with the end of the aperture portion with the surface around the aperture portion of the concave portion as a reference. This is the length when the distance between the two straight lines is minimized when the concave portion is sandwiched between the straight lines. For example, when the surface shape of the concave shape portion is circular, the diameter is indicated, and when the surface shape of the concave shape portion is elliptical, the short diameter is indicated.

  In the electrophotographic photosensitive member according to the present invention, the distance (Rdv) between the deepest portion of the concave portion and the aperture surface is based on the surface around the aperture portion of the concave portion, as shown in FIG. And the distance between the deepest part of the concave part and the aperture surface.

  In the electrophotographic photosensitive member according to the present invention, the concave portion is formed at least on the surface of the underlayer of the electrophotographic photosensitive member, that is, the intermediate layer or the conductive layer in order to affect the formation of the electrostatic latent image on the photosensitive layer. Is done.

  Here, in the electrophotographic photosensitive member according to the present invention, how to take the areas A to E will be described with reference to FIGS. FIG. 4 is a view showing the support 1 and the underlayer 2 provided on the support in the electrophotographic photosensitive member according to the present invention, and the straight line OP in the figure is a result of dip coating on the underlayer. A straight line parallel to the pulling direction is shown. FIG. 5 is a diagram illustrating how to take the areas A to E and how to take the measurement area in the present invention. FIG. 5 shows the surface of the base layer 2 in the support on which the base layer shown in FIG. 4 is formed, cut along a straight line OP extending in parallel with the dip coating pulling direction on the base layer surface and developed. Further, the point O ′ and the point P ′ in FIG. 5 are points that overlap with the point O and the point P in FIG. 4 before the development as described above. Point O is the application start side, and point P is the application end side. In the dip coating method of the present invention, the upstream end in the pulling direction in which the coating film is first formed is the application start end, and the downstream end is the application end. By dividing the quadrangle OPP'O 'in FIG. 5 into five equal parts in the pulling-up direction of the photoreceptor, the regions A to E can be taken as shown in FIG. In other words, the areas A to E are allocated according to the position in which the respective areas divided into five are arranged in the pulling direction. In the present invention, each of the areas A to E is allocated from upstream to downstream in the pulling direction. Area A, area B, area C, area D, and area E are assigned.

  In the electrophotographic photosensitive member according to the present invention, the distance (Rdv) between the deepest portion of the concave shape portion and the aperture surface is a concave portion formed on the dip coating end side from the concave shape portion formed on the dip coating start side. It gradually increases toward the shape part. In addition, Rdv ′ corresponding to the region on the coating end side is large in the distance (Rdv ′) between the deepest portion and the aperture in the regions A, B, C, D, and E defined as described above. It is preferable. Within this range, it is possible to easily and efficiently produce a photoconductor having a high uniformity of electrostatic latent image with respect to the pulling direction of dip coating.

  In the electrophotographic photoreceptor according to the present invention, it is preferable that the number of the concave-shaped portions in the region E closest to the coating end among the regions A to E is 10 or more per 100 μm square. In this case, the number per 100 μm square means that a square region having a side of 100 μm is included in each of four regions obtained by dividing the region E into four equal parts in the rotation direction of the photosensitive member, as shown in FIG. It is the number measured by setting. If the number is small, sufficient effects of the present invention may not be exhibited depending on the coating conditions of the photosensitive layer. Note that the magnitude of Rdv in the areas A to E gradually increases so as to eliminate the nonuniformity of the latent image potential between the application start side and the application end side.

  In the electrophotographic photosensitive member according to the present invention, the average distance (Rdv-A) between the deepest portion of the concave portion and the aperture surface per 100 μm square of the underlayer surface is configured as follows. Is preferred. That is, it is preferable that Rdv-A gradually increase from the concave shape portion formed on the application start side toward the concave shape portion formed on the application end side. Thereby, good uniformity of the electrostatic latent image can be obtained. Further, in the average distance (Rdv′−A) between the deepest portion of the concave shape portion per 100 μm square and the aperture surface in the regions A, B, C, D, and E defined as described above. The Rdv′-A corresponding to the region on the application end side is preferably larger than the Rdv′-A corresponding to the region on the application start side. Thereby, good uniformity of the electrostatic latent image can be obtained. Note that the average distance (Rdv′-A) between the deepest portion of the concave shape portion per 100 μm square and the aperture surface is divided into four equal parts in the photosensitive member rotation direction as shown in FIG. Each of the four regions obtained in this way is measured by providing a square region with a side of 100 μm.

  In the electrophotographic photosensitive member that satisfies the above conditions, in the pulling direction during dip coating, high uniformity of the electrostatic latent image is achieved, and it is likely to occur during full color printing. Color unevenness can be suppressed.

  In the present invention, a method of achieving high uniformity of an electrostatic latent image by having a specific concave portion on the surface of the intermediate layer or conductive layer of the electrophotographic photosensitive member is shown. I guess what is shown in

  In general, in the dip coating method, the part on the application end side is immersed in the coating solution for a long time relative to the part on the application start side. It is presumed that this causes some difference between the laminated films and causes non-uniformity of the electrostatic latent image. In such a situation, by having each concave-shaped part of a greater depth to the part immersed in the coating liquid for a long time, the cause of causing non-uniformity of the electrostatic latent image is eliminated, Alternatively, it is considered that the uniformity of the electrostatic latent image can be obtained by obtaining the canceling effect.

  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 measuring microscope VK-8550, ultra-deep shape measuring microscope VK-9000, and ultra-deep shape measuring microscope VK-9500 (all manufactured by Keyence Corporation)
Surface shape measurement system Surface Explorer SX-520DR (manufactured by Ryoka System Co., Ltd.)
Scanning confocal laser microscope OLS3000 (manufactured by Olympus Corporation)
Real Color Confocal Microscope Oplitex C130 (made by Lasertec Corporation)

  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 Nanotechnology Inc.)
Scanning electron microscope SUPERSCAN SS-550 (manufactured by Shimadzu Corporation)

  For example, the following equipment can be used as the atomic force microscope.

Nanoscale hybrid microscope VN-8000 (manufactured by Keyence Corporation)
Scanning Probe Microscope NanoNavi Station (SII Nano Technology 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. it can. In addition, the number of concave portions per unit area can be obtained.

As an example, a measurement example using an analysis program by the Surface Explorer SX-520DR type machine will be described. The electrophotographic photosensitive member to be measured is placed on the work table, and the tilt is adjusted to adjust the horizontal, and the three-dimensional shape data of the peripheral surface of the electrophotographic photosensitive member is captured in the wave mode. At this time, the magnification of the objective lens may be 50 times, and 100 μm × 100 μm (10000 μm ² ) may be used for visual field observation.

  Next, the contour line data of the surface of the electrophotographic photosensitive member is displayed using a particle analysis program in the data analysis software.

The hole analysis parameters of the concave portion such as the shape of the concave portion, the major axis diameter, the depth, and the opening portion area can be optimized by the formed concave portion. For example, when observing and measuring a concave portion having a major axis diameter of about 10 μm, the major axis diameter upper limit is 15 μm, the major axis diameter lower limit is 1 μm, the depth lower limit is 0.1 μm, and the volume lower limit is 1 μm ³ or more. Good. Then, the number of concave portions that can be identified as concave portions on the analysis screen is counted, and this is used as the number of concave portions.

  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 a surface for performing shape transfer by pressing a mold having a predetermined shape against the surface of the underlayer will be described.

  FIG. 6 is a diagram showing an example of a schematic diagram of a pressure contact shape transfer processing apparatus using a mold according to the present invention. In this forming method, after a predetermined mold 13 is attached to the pressure device 12 that can repeatedly press and release, the mold is brought into contact with the underlying layer of the photoconductor 14 with a predetermined pressure to transfer the shape. Thereafter, the pressurization is once released and the underlying layer of the photoreceptor 14 is rotated, and then the pressurization and shape transfer process is performed again. By repeating this process, it is possible to form a predetermined concave shape portion around the entire circumference of the underlayer.

  Further, for example, as shown in FIG. 7, in the above-described forming method, first, after a mold 13 having a predetermined shape about the entire circumference of the underlayer of the photoreceptor 14 is attached to the pressurizing device 12, the photosensitive device A predetermined pressure may be applied to the base layer of the body 14. Thereafter, a predetermined concave portion may be formed over the entire circumference of the underlayer by rotating and moving the photosensitive member.

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

  Further, the mold or the underlayer may be heated for the purpose of efficiently transferring the shape. The heating temperature of the mold and the underlayer is arbitrary as long as the above-described concave portion in the present invention can be formed. The temperature (° C.) of the mold during shape transfer is the glass transition temperature (° C. of the underlayer on the support. ) It is preferably heated so as to be higher. Furthermore, in addition to heating the mold, it is preferable that the temperature (° C.) of the support during shape transfer is controlled to be lower than the glass transition temperature (° C.) of the underlayer. By doing in this way, the concave-shaped part transcribe | transferred on the photoreceptor surface can be formed stably.

  The material, size, and shape of the mold itself may be selected as appropriate. Examples of the material of the mold include a metal having a fine surface processed and a silicon wafer surface patterned with a resist, a resin film in which fine particles are dispersed, and a resin film having a predetermined fine surface shape coated with metal. It is done. An example of the shape of the mold is shown in FIG. 8 (partially enlarged view of the photoreceptor contact surface) and FIG. 9 (partially enlarged view of the photoreceptor contact surface section).

  Moreover, you may provide an elastic body between a mold and a pressurization apparatus in order to provide the uniformity of a pressure with respect to a base layer.

  The concave portion having the above shape can be formed on the underlying layer constituting the electrophotographic photosensitive member by a surface forming method in which the mold having the predetermined shape is pressed against the surface of the underlying layer to transfer the shape. .

  In the case of forming a surface for performing shape transfer by pressing a mold having a predetermined shape against the surface of the underlayer, the distance between the deepest portion of the concave portion and the aperture surface is preferably 20 μm or less. By using a surface forming method in which a mold having a predetermined shape is pressed against the surface of the underlayer to transfer the shape, the size, shape and arrangement of the concave portions are highly controllable, with high accuracy and high flexibility. Surface treatment of the underlayer can be realized.

  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 the example of the formation method of the electrophotographic photoreceptor surface is given, following (1)-(3) will be mentioned.

(1) A method of 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 mold having a predetermined shape is pressed against the surface of the electrophotographic photosensitive member. Method for forming surface for shape transfer (3) Method for forming a surface by condensing the surface when forming a surface layer of an electrophotographic photosensitive member

  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 laser light 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 that can be used in the above 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. 10 are appropriately arranged may be used. Only the laser beam that has passed through the mask is condensed by the lens and irradiated onto the surface of the electrophotographic photosensitive member, whereby a concave portion having a desired shape and arrangement can be formed. In the method of forming the surface of the electrophotographic photosensitive member by laser irradiation as described above, 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. 11, first, the photosensitive drum 9 is rotated by the work rotation motor 7. While rotating, the excimer laser beam irradiator 6 is shifted in the axial direction of the photosensitive drum by the work moving device 8. Thereby, it is possible to efficiently form the concave portion over the entire surface of the photosensitive drum 9.

  By the above-described method for forming the surface of the underlayer by laser irradiation, the concave portion having the above shape can be formed on the underlayer constituting the electrophotographic photosensitive member.

  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 the 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 shape portion and the aperture surface by one irradiation is 0.1 μm or more. And it is preferably 2.0 μm or less. Furthermore, it is preferable that this distance by one irradiation is 0.3 μm or more and 1.2 μm or less. FIG. 12 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. .

  In addition, as long as surface processing of the underlayer can be performed by a method with high controllability of shape and arrangement, it can be appropriately used in the present invention. For example, a method may be used in which the surface is condensed during the formation of the underlayer described below to form the surface.

  In other words, the surface forming method in which the surface is dewed when forming the underlayer of the electrophotographic photosensitive member includes the following steps (1) to (3).

(1) A coating liquid for an underlayer containing a binder resin and an organic solvent, the content of the organic solvent being 30% by mass or more and 80% by mass or less with respect to the total mass of the solvent in the coating solution for the underlayer is prepared. , A coating process for coating this coating solution,
(2) A support holding process in which the support coated with the coating liquid is held and the surface of the support coated with the coating liquid is condensed, and (3) a drying process in which the support is heated and dried.

  Thereby, the base layer in which the concave-shaped part which became independent on the surface was formed can be produced.

  Said concave shape part is controllable by adjusting manufacturing conditions within the range shown with 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 photoreceptor according to the present invention includes a support and a photosensitive layer (hereinafter also simply referred to as “photosensitive layer”) provided on the support. The electrophotographic photosensitive member according to the present invention is generally a cylindrical organic electrophotographic photosensitive member in which a photosensitive layer is formed on a cylindrical support. However, a belt-like or sheet-like shape is also possible. is there.

  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 It may be a laminated type (functionally separated type) photosensitive layer separated. 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. Moreover, the said metal support body which has the layer by which aluminum, the aluminum alloy, or the indium oxide tin oxide alloy was formed into a film by vacuum deposition can also be used. A resin support (polyethylene terephthalate, polybutylene terephthalate, phenol resin, polypropylene or polystyrene resin) 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.

The volume resistivity of the support, if the surface of the support is a layer provided in order to impart conductivity, the volume resistivity of the layer is preferably from 1 × ¹⁰ 10 Ω · cm, 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 may be 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

  Examples of the binder resin used at the same time include the following.

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-vinyl carbazole Acrylic resin Silicone resin Epoxy resin Melamine resin Urethane resin Phenolic resin Alkyd resin Other thermoplastic resin Thermosetting resin Photocurable resin

  The conductive layer can be formed by dispersing or dissolving the conductive powder and the binder resin in the following solvent and applying them.

Ether solvents such as tetrahydrofuran or ethylene glycol dimethyl ether Alcohol solvents such as methanol Ketone solvents such as methyl ethyl ketone Aromatic hydrocarbon solvents such as toluene

  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. Even more preferably.

  The surface of the conductive layer in which the conductive pigment or the 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. it can.

  Examples of the binder resin for the intermediate layer include the following.

Water-soluble resin such as polyvinyl alcohol, polyvinyl methyl ether, polyacrylic acid, methyl cellulose, ethyl cellulose, polyglutamic acid or casein Polyamide resin Polyimide resin Polyamideimide resin Polyamic acid resin Melamine resin Epoxy resin Polyurethane resin Polyglutamic acid ester resin

  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 coating property, adhesion, solvent resistance and resistance. For this, a thermoplastic polyamide resin is preferred. 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 order to prevent the flow of electric charges (carriers) in the intermediate layer, semiconductive particles are dispersed in the intermediate layer, or an electron transporting material (an electron accepting material such as an acceptor) is contained. You may let them.

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

  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 acid anhydride or perylene imide many such as anthraquinone or pyrenequinone Ring quinone pigments Squaryllium 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 Quinone imine dyes Styryl dyes

  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, examples of the binder resin used for the charge generation layer include the following.

Polycarbonate resin Polyester resin Polyarylate resin Butyral resin Polystyrene resin Polyvinyl acetal resin Diallyl phthalate resin Acrylic resin Methacrylic resin Vinyl acetate resin Phenolic resin Silicone resin Polysulfone resin Styrene-butadiene copolymer resin Alkyd resin Epoxy resin Urea resin Vinyl chloride-vinyl acetate copolymer Combined resin

  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 the following.

Acrylic resin Styrene resin Polyester resin Polycarbonate resin Polyarylate resin Polysulfone resin Polyphenylene oxide resin Epoxy resin Polyurethane resin Alkyd resin Unsaturated resin

  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 hydrocarbon solvents such as toluene, xylene or chlorobenzene

  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 order to improve the durability performance, which is one of the characteristics required for the electrophotographic photoreceptor according to the present invention, in the case of the above-described function-separated photoreceptor, the material design of the charge transport layer as the surface layer is important. 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.

  Next, a process cartridge and an electrophotographic apparatus according to the present invention will be described. FIG. 13 is a diagram showing an example of a schematic configuration of an electrophotographic apparatus provided with a process cartridge having an electrophotographic photosensitive member according to the present invention.

  In FIG. 13, reference numeral 15 denotes a cylindrical electrophotographic photosensitive member, which is rotationally driven in a direction of an arrow about a shaft 16 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 photoreceptor 15 is developed with toner contained in the developer of the developing unit 19 to become a toner image. Next, the toner image formed and supported on the surface of the electrophotographic photosensitive member 15 is sequentially transferred onto a transfer material (for example, paper) 25 by a transfer bias from a transfer unit (for example, a transfer roller) 20. The transfer material 25 may be fed from a transfer material supply means (not shown) between the electrophotographic photoreceptor 15 and the transfer means 20 (contact portion) in synchronization with the rotation of the electrophotographic photoreceptor 15. Good.

  The transfer material 25 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 where the image is fixed and printed out as an image formed product (print, copy). Is done.

  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. 13, 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 the main body of an electrophotographic apparatus such as a copying machine or a laser beam printer. In FIG. 13, 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. In addition, the process cartridge 23 is detachably attached to the main body of the electrophotographic apparatus by using guide means 24 such as a rail of the main body of the electrophotographic apparatus.

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

<Preparation of electrophotographic photosensitive member 1 for estimating the depth of the concave portion>
As a cylindrical support, an aluminum cylinder (JIS-A3003, aluminum alloy) having a length of 257 mm and a diameter of 24 mm manufactured by an extrusion / pulling process was used.

  Next, a solution composed of the following components was dispersed with a ball mill for about 20 hours to prepare a conductive layer coating.

60 parts of powder composed of barium sulfate particles having a tin oxide coating layer (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.)
1-methoxy-2-propanol 50 parts Methanol 50 parts

  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, the following components were dissolved in a mixed solution of 400 parts of methanol / 200 parts of n-butanol to prepare an intermediate layer coating material.

Copolymer nylon resin 10 parts (Product 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.)

  This intermediate layer coating material is dip-coated on the conductive layer and 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 1.00 μm. A layer was formed.

  Moreover, the length in the longitudinal direction of the applied underlayer composed of the conductive layer and the intermediate layer was 250 mm.

  Next, the following components were dispersed for 4 hours in a sand mill apparatus using glass beads having a diameter of 1 mm, and then 700 parts of ethyl acetate was added to prepare a charge generation layer coating material.

Bragg angles (2θ ± 0.2 °) have strong peaks at 7.5 °, 9.9 °, 16.3 °, 18.6 °, 25.1 ° and 28.3 ° in CuKα characteristic X-ray diffraction 20 parts of crystalline form of hydroxygallium phthalocyanine 0.2 parts of 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.)
600 parts of cyclohexanone

  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, the following components were dissolved in a mixed solvent of 600 parts of chlorobenzene and 200 parts of methylal to prepare a charge transport layer coating material.

  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)
100 parts (Iupilon Z-400, manufactured by Mitsubishi Engineering Plastics) [viscosity average molecular weight (Mv) 40,000]

  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. In this way, an electrophotographic photoreceptor 1 for estimation was obtained.

<Characteristic evaluation of electrophotographic photoreceptor>
The obtained electrophotographic photosensitive member is mounted on a color laser jet 4650 of HP laser beam printer in an environment of a temperature of 23 ° C. and a relative humidity of 50%, and the electrostatic latent image potential is evaluated. went. The main body was modified to make the charging bias and image exposure variable. Further, the charging bias was adjusted so that VD was −600V. Further, the amount of image exposure light was changed so that the VL at the upper end 25 mm position was −200V. And it divided into 5 area | regions in the longitudinal direction, made the center into the electric potential characteristic measurement part, and measured. As a result, it was confirmed that the VL at the 25 mm position was −22 V from the VL at the 225 mm position.

<Production of electrophotographic photosensitive member 2 for estimating the depth of the concave portion>
<Formation of concave shaped part by mold press-fit shape transfer>
Using a device having the following specifications, the mold was added to the 200 mm position to the 250 mm position of the support coated up to the intermediate layer obtained in the same manner as the electrophotographic photosensitive member 1 for estimating the depth of the concave portion. The shape was transferred by pressing. In other words, this apparatus is the same as the apparatus shown in FIG. 7 except that the shape transfer mold having the cylinder arrangement shown in FIG. 8 and having a cylinder with a diameter RM of 10.0 μm and a height HM of 3.0 μm. It is what you have. At this time, pressure was applied while adjusting the pressure to 30.0 MPa and the mold temperature to 100 ° C., and shape transfer was performed by rotating the photoreceptor in the circumferential direction. In this way, an electrophotographic photoreceptor 2 for estimation was obtained.

<Observation of formed concave part>
The surface shape of the obtained underlayer was enlarged and observed using a laser microscope (VK-9500 manufactured by Keyence Corporation). As a result, in the arrangement shown in FIG. 14, the long axis diameter Rpc is 5.0 μm, the short axis diameter Lpc is 5.0 μm, and the distance Rdv between the deepest part and the aperture surface is 1.3 μm. It was confirmed that was formed.

<Characteristic evaluation of electrophotographic photoreceptor>
When the VL of the electrophotographic photosensitive member thus produced was measured in the same manner as the electrophotographic photosensitive member 1 for estimating the depth of the concave portion, the VL at the 25 mm position was −3 V from the VL at the 225 mm position. It was confirmed that there was.

Example 1
<Formation of concave shaped part by mold press-fit shape transfer>
In the same manner as the electrophotographic photosensitive member 1 for estimating the depth of the concave shape portion, the support coated up to the obtained intermediate layer is divided into five regions in the longitudinal direction, and the vicinity of the center is the mold observation portion. And a sensitivity measurement unit. And shape transfer was performed by mold pressurization using an apparatus having the following specifications. That is, this apparatus is provided with a mold having the columnar arrangement shown in FIG. 8 in the apparatus shown in FIG. In addition, this mold has a diameter RM of 10.0 μm, a height HM of 0 μm at the 25 mm position of the photoconductor for shape transfer, and 3.0 μm at the 225 mm position. There is a mold having a cylinder with varying HM. The obtained electrophotographic photosensitive member was subjected to surface shape measurement and characteristic evaluation, and then a photosensitive layer was formed in the same manner as the electrophotographic photosensitive member 1 for estimating the depth of the concave portion.

<Observation of formed concave part>
When an enlarged observation was performed in the same manner as the electrophotographic photosensitive member 2 for estimating the depth of the concave portion, the concave portion having a major axis diameter Rpc of 5.0 μm and a minor axis diameter Lpc of 5.0 μm in the arrangement shown in FIG. It was confirmed that was formed. Further, it was confirmed that the distance Rdv between the deepest portion and the aperture surface differs depending on the position.

<Characteristic evaluation of electrophotographic photoreceptor>
The VL of the region of the electrophotographic photosensitive member thus prepared was measured in the same manner as the electrophotographic photosensitive member 1 for estimating the depth of the concave portion. The results are shown in Table 1. Similarly, the obtained electrophotographic photosensitive member was mounted on a Color LaserJet-4650, a laser beam printer manufactured by HP, under an environment of a temperature of 23 ° C./relative humidity of 50%, and the image was evaluated. . The CRG provided in the same electrophotographic photosensitive member was attached to each station, and the color unevenness and density unevenness when a halftone image was output were judged visually to make an image evaluation.

(Example 2)
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the thickness of the intermediate layer was 1.0 μm and the concave portion was formed as follows.

<Formation of concave shaped part by mold press-fit shape transfer>
The support coated up to the intermediate layer was divided into five regions in the longitudinal direction, and the vicinity of the center was used as a mold observation part and a sensitivity measurement part. And shape transfer was performed by mold pressurization using an apparatus having the following specifications. That is, this apparatus is provided with a mold having the columnar arrangement shown in FIG. 8 in the apparatus shown in FIG. Further, this mold has a diameter RM of 8.0 μm, a height HM of 0 μm at the 25 mm position of the photoconductor to which the shape is transferred, and 2.0 μm at the 225 mm position, and is linearly high at the middle and outer portions. It is a mold having a cylinder in which HM varies. The obtained electrophotographic photoreceptor was subjected to surface shape measurement and characteristic evaluation 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 except that the concave portion was formed as follows.

<Formation of concave shaped part by mold press-fit shape transfer>
The support coated up to the intermediate layer was divided into five regions in the longitudinal direction, and the vicinity of the center was used as a mold observation part and a sensitivity measurement part. And shape transfer was performed by mold pressurization using an apparatus having the following specifications. That is, this apparatus includes the mold having the columnar arrangement shown in FIG. 16 in the apparatus shown in FIG. In addition, this mold has a diameter RM of 10.0 μm, a height HM of 0 μm at the 25 mm position of the photoconductor for shape transfer, and 3.0 μm at the 225 mm position. A mold having a cylinder in which HM varies.

<Observation of formed concave part>
The surface shape of the obtained underlayer was enlarged and observed using a laser microscope (VK-9500 manufactured by Keyence Corporation). As a result, it was confirmed that a concave portion having a major axis diameter Rpc of 5.0 μm and a minor axis diameter Lpc of 5.0 μm was formed in the arrangement shown in FIG. Further, it was confirmed that the distance Rdv between the deepest portion and the aperture surface differs depending on the position. The obtained electrophotographic photoreceptor was subjected to surface shape measurement and characteristic evaluation 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 except that a honing cylinder having a length of 257 mm and a diameter of 24 mm obtained by the following production method was used as a support, and no conductive layer was formed.

<Liquid honing conditions>
Abrasive grain: spherical alumina bead average particle diameter 30 μm (Showa Denko CB-A30S)
Suspension medium: Water Abrasive / Suspension medium: 1/10 (volume ratio)
Number of rotations of aluminum cutting tube: 1.67 s ⁻¹
Air spray pressure: 0.15 MPa
Gun moving speed: 13.3 mm / sec Distance between gun nozzle and aluminum cutting tube: 200 mm
Honing abrasive grain discharge angle: 45 °
Number of polishing liquid projections: 1 (one way)

  The obtained electrophotographic photoreceptor was subjected to surface shape measurement and characteristic evaluation 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 4 except that the intermediate layer was formed as follows.

  First, the following components were dissolved in 45 parts of butanol to prepare an intermediate layer coating.

Zirconium compound 20 parts (trade name: Olga Chicks ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.)
Silane compound 2.5 parts (trade name: A1100, manufactured by Nihon Unicar)
Polyvinyl butyral resin 2.5 parts (trade name: S-Rex BM-S, manufactured by Sekisui Chemical Co., Ltd.)

  This intermediate layer coating material is dip-coated on the above support and dried by heating in an oven heated to 150 ° C. for 10 minutes, so that the average film thickness at the position 130 mm from the upper end of the support is 1.6 μm. A layer was formed. Moreover, the length in the longitudinal direction of the applied underlayer composed of the conductive layer and the intermediate layer was 250 mm.

  The obtained electrophotographic photoreceptor was subjected to surface shape measurement and characteristic evaluation in the same manner as in Example 1. The results are shown in Table 1.

(Example 6)
<Electrophotographic photoconductor 3 for estimating the depth of the concave portion>
In the same manner as the electrophotographic photosensitive member 1 for estimating the depth of the concave portion, a mold is formed using the apparatus having the following specifications with respect to the 200 mm position to the 250 mm position of the support coated up to the obtained conductive layer. Shape transfer was performed by applying pressure. That is, this apparatus includes the apparatus shown in FIG. 7 having the cylindrical arrangement shown in FIG. This mold is a mold having a cylinder with a diameter RM of 12.0 μm and a height HM of 6.3 μm. At this time, pressure was applied while adjusting the pressure to 30.0 MPa and the mold temperature to 150 ° C., and the shape was transferred by rotating the photoreceptor in the circumferential direction. Thus, an electrophotographic photoreceptor 3 was obtained.

<Observation of formed concave part>
The surface shape of the obtained underlayer was enlarged and observed using a laser microscope (VK-9500 manufactured by Keyence Corporation). As a result, in the arrangement shown in FIG. 14, the long axis diameter Rpc is 7.3 μm, the short axis diameter Lpc is 7.3 μm, and the distance (Rdv) between the deepest portion and the aperture surface is 2.2 μm. It was confirmed that the shape part was formed.

<Characteristic evaluation of electrophotographic photoreceptor>
When the VL of the electrophotographic photosensitive member thus produced was measured in the same manner as the electrophotographic photosensitive member 1 for estimating the depth of the concave portion, the VL at the 25 mm position was −3 V from the VL at the 225 mm position. It was confirmed that there was.

<Production of electrophotographic photoreceptor>
<Formation of concave shaped part by mold press-fit shape transfer>
In the same manner as the electrophotographic photosensitive member 3 for estimating the depth of the concave portion, the support coated up to the obtained conductive layer is divided into five regions in the longitudinal direction, and the vicinity of the center is the mold observation portion. And a sensitivity measurement unit. And shape transfer was performed by mold pressurization using the apparatus of the following specification. That is, this apparatus is provided with a mold having the columnar arrangement shown in FIG. 8 in the apparatus shown in FIG. In addition, this mold has a diameter RM of 12.0 μm, a height HM of 0 μm at the 25 mm position of the photoconductor for shape transfer, and 6.3 μm at the 225 mm position. A mold having a cylinder in which HM varies.

<Observation of formed concave part>
Enlarged observation was performed in the same manner as the electrophotographic photosensitive member 3 for estimating the depth of the concave portion. As a result, it was confirmed that a concave portion having a major axis diameter Rpc of 5.0 μm and a minor axis diameter Lpc of 5.0 μm was formed in the arrangement shown in FIG. Further, it was confirmed that the distance Rdv between the deepest portion and the aperture surface differs depending on the position.

<Characteristic evaluation of electrophotographic photoreceptor>
The VL of the region of the electrophotographic photosensitive member thus prepared was measured in the same manner as the electrophotographic photosensitive member 1 for estimating the depth of the concave portion. 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 6 except that the thickness of the intermediate layer was 1.0 μm and the concave portion was formed as follows.

<Formation of concave shaped part by mold press-fit shape transfer>
The support coated up to the conductive layer was divided into five regions in the longitudinal direction, and the vicinity of the center was used as a mold observation part and a sensitivity measurement part. And shape transfer was performed by mold pressurization using an apparatus having the following specifications. That is, this apparatus is provided with a mold having the columnar arrangement shown in FIG. 8 in the apparatus shown in FIG. Further, this mold has a diameter RM of 6.0 μm, a height HM of 0 μm at the 25 mm position of the photoconductor to which the shape is transferred, and 3.6 μm at the 225 mm position, and is linearly high at the middle and outer portions. It is a mold having a cylinder in which HM varies. The obtained electrophotographic photoreceptor was subjected to surface shape measurement and characteristic evaluation 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 6 except that the concave portion was formed as follows.

<Formation of concave shape by excimer laser>
A concave portion was formed on the obtained underlayer using a KrF excimer laser (wavelength λ = 248 nm). At this time, as shown in FIG. 15, a quartz glass mask having a pattern in which circular laser beam transmitting portions 5 having a diameter of 30 μm are arranged at intervals of 10 μm was used. The excimer laser irradiation energy was 0.9 J / cm ³ and the irradiation area per irradiation was 2 mm ² . As shown in FIG. 11, the workpiece was rotated, and irradiation was performed while shifting the irradiation position in the axial direction. At this time, by increasing the number of times of irradiation at the same location from the application start side to the application end side, the distance (Rdv) between the deepest portion and the aperture surface gradually increases from the application start side to the application end side. It was formed to be large.

<Observation of formed concave part>
The surface shape of the obtained underlayer at a position of 225 mm was enlarged and observed using a laser microscope (VK-9500 manufactured by Keyence Corporation). As a result, in the arrangement shown in FIG. 14, the long axis diameter Rpc is 6.8 μm, the short axis diameter Lpc is 6.8 μm, and the distance Rdv between the deepest part and the aperture surface is 1.0 μm. It was confirmed that was formed. Further, it was confirmed that the distance Rdv between the deepest portion and the aperture surface differs depending on the position. The obtained electrophotographic photoreceptor was subjected to surface shape measurement and characteristic evaluation 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 8 except that the irradiation conditions were adjusted so that the number of 100 μm squares was reduced over the entire surface when the concave portion was formed. The obtained electrophotographic photoreceptor was subjected to surface shape measurement and characteristic evaluation in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 1)
The following steps were carried out in the same manner as in Example 1 except that the concave portion was not formed. The results 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 2 except that the concave portion was formed as follows.

<Formation of concave shaped part by mold press-fit shape transfer>
Shape transfer was performed on the support coated up to the intermediate layer by pressurizing the mold using an apparatus having the following specifications. That is, this apparatus is provided with a mold having the columnar arrangement shown in FIG. 8 in the apparatus shown in FIG. This mold is a mold having a cylinder with a diameter RM of 10.0 μm and a height HM of 3.0 μm. At this time, pressure was applied while adjusting the pressure to 30.0 MPa and the mold temperature to 100 ° C., and shape transfer was performed by rotating the photoreceptor in the circumferential direction. The obtained electrophotographic photoreceptor was subjected to surface shape measurement and characteristic evaluation in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 3)
<Production of electrophotographic photoreceptor>
An electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the concave portion was formed as follows.

<Formation of concave shaped part by mold press-fit shape transfer>
Shape transfer was performed on the support coated up to the intermediate layer by pressurizing the mold using an apparatus having the following specifications. That is, this apparatus is provided with a mold having the columnar arrangement shown in FIG. 8 in the apparatus shown in FIG. This mold has a diameter RM of 50.0 μm, a height HM of 0 μm at the 25 mm position of the photoconductor for shape transfer, and 15.0 μm at the 225 mm position, and a linear height at the middle and outer portions. It is a mold having a cylinder in which HM varies. The obtained electrophotographic photoreceptor was subjected to surface shape measurement and characteristic evaluation in the same manner as in Example 1. 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, Comprising: The arrow in a figure shows the major axis diameter (Rpc) in a concave shape part. It is a figure which shows the example of the surface shape of the concave shape part in this invention, Comprising: The arrow in a figure shows the short-axis diameter (Lpc) in a concave shape part. It is a figure which shows the example of the cross-sectional shape of the concave shape part in this invention, Comprising: The arrow in a figure shows the major axis diameter (Rpc) in a concave shape part, and the distance (Rdv) of a deepest part and an aperture surface. 1 is a view showing a support 1 and an underlayer 2 provided on the support in an electrophotographic photosensitive member according to the present invention, and a straight line OP in the drawing is parallel to a pulling direction at the time of dip coating on the underlayer. A straight line. It is a figure which shows how to take the area | region AE in this invention, and how to take a measurement area | region. 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). 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. 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. 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 example (partial enlarged view) of the arrangement pattern of the laser mask used in Example 1. FIG. It is a figure which shows the shape of the mold (partial enlarged view of a photoreceptor contact surface) used in Example 3. FIG. 10 is a diagram illustrating an array pattern (partially enlarged view) of concave-shaped portions on the outermost surface of the photoconductor in Example 3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Support body 2 Underlayer 3 Concave-shaped part 4 Laser light shielding part 5 Laser light transmitting part 6 Excimer laser light irradiator 7 Work rotation motor 8 Work moving device 9 Photosensitive drum 10 Concave-shaped part non-forming part 11 Concave-shaped part Forming part 12 Pressure device 13 Mold 14 Photoconductor 15 Electrophotographic photoreceptor 16 Axis 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 (7)

On a support, there is at least a conductive layer or an intermediate layer consisting of either an intermediate layer or a photosensitive layer, and a laminated electrophotographic photosensitive member in which the photosensitive layer is formed by a dip coating method,
The surface of the foundation layer has a plurality of independent concave portions,
The major axis diameter (Rpc) of each surface opening portion of the concave portion is 30 μm or less,
The short axis diameter (Lpc) of each surface opening portion of the concave shape portion is 1.0 μm or more,
The distance (Rdv) between the deepest portion of the concave shape portion and the aperture surface is gradually increased from the concave shape portion formed on the coating start side toward the concave shape portion formed on the coating end side. An electrophotographic photoreceptor characterized by the above.   Regions obtained by dividing the electrophotographic photosensitive member into 5 equal parts in the pulling direction at the time of dip coating are designated as regions A, B, C, D, and E from upstream to downstream in the pulling direction, respectively. When the distance (Rdv) between the deepest part of the concave-shaped part and the aperture surface in the region is Rdv ′ in the region A, region B, region C, region D, and region E, it corresponds to the region on the coating end side. 2. The electrophotographic photosensitive member according to claim 1, wherein Rdv ′ is larger than Rdv ′ corresponding to a region on a coating start side.   When the areas obtained by dividing the electrophotographic photosensitive member into 5 equal parts in the pulling direction at the time of dip coating are the areas A, B, C, D, and E from the downstream to the upstream in the pulling direction, 3. The electrophotographic photosensitive member according to claim 1, wherein the number of the concave-shaped portions in the region E that is closest to the coating end is 10 or more per 100 μm square.   The average distance (Rdv-A) between the deepest part of the concave part and the aperture surface gradually increases from the concave part formed on the application start side toward the concave part formed on the application end side. The electrophotographic photosensitive member according to any one of claims 1 to 3.   Regions obtained by dividing the electrophotographic photosensitive member into 5 equal parts in the pulling direction at the time of dip coating are designated as regions A, B, C, D, and E from upstream to downstream in the pulling direction, respectively. When the average distance (Rdv-A) between the deepest portion of the concave-shaped portion and the aperture surface in the region is Rdv′-A in the region A, region B, region C, region D, and region E, the coating is completed. 5. The electrophotographic photosensitive member according to claim 1, wherein Rdv′-A corresponding to the region on the side is larger than Rdv′-A corresponding to the region on the coating start side.   A main body of an electrophotographic apparatus, integrally supporting the electrophotographic photosensitive member according to any one of claims 1 to 5 and at least one means selected from the group consisting of a charging means, a developing means, and a cleaning means. A process cartridge that is detachable.   An electrophotographic apparatus comprising the electrophotographic photosensitive member according to claim 1, and a charging unit, an exposing unit, a developing unit, and a transferring unit.