JP2008281698A - Electrophotographic equipment - Google Patents

Abstract

An electrophotographic apparatus having brush fibers located on the downstream side of a transfer unit and on the upstream side of a charging unit and in contact with the surface of an electrophotographic photosensitive member suppresses a defective image and contamination of the charging unit.
An electrophotographic apparatus comprising brush fibers (6, 7) for applying a transfer residual toner to a surface of an electrophotographic photosensitive member (1) after collecting the transfer residual toner. Has a plurality of concave portions on the surface layer, and the depth Rv of the concave portions is 0.3 μm or more and 2.0 μm or less, and the length of the concave portions in the longitudinal direction of the electrophotographic photosensitive member 1 is long. The relationship between the shaft diameter La and the brush longest diameter Lc is expressed by the following equation (1).

And the minor axis diameter of the concave portion is smaller than the weight average particle diameter of the toner, and the number of concave portions is 60 or more per 100 μm square.
[Selection] Figure 8

Description

  The present invention relates to an electrophotographic apparatus. In particular, the present invention relates to an image forming apparatus in which a developing unit performs cleaning simultaneously with development.

  2. Description of the Related Art Conventionally, as an electrophotographic apparatus using an electrophotographic system such as a copying machine, a printer, and a facsimile, an apparatus having the following configuration has been put into practical use. An electrophotographic photosensitive member as a latent image carrier, a charging means for charging the electrophotographic photosensitive member, and development for developing an electrostatic latent image formed on the electrophotographic photosensitive member with toner as a developer Means. Then, a transfer unit that transfers the visualized toner onto a transfer material such as paper, a cleaning unit that cleans the residual toner remaining on the electrophotographic photosensitive member, and a fixing unit that fixes the toner on the transfer material. Is also provided.

  In recent years, there has been an image forming apparatus in which cleaning means has been eliminated, and transfer residual toner on the electrophotographic photosensitive member after transfer is removed and collected from the electrophotographic photosensitive member by “development simultaneous cleaning” in the developing means and reused. is there.

  The simultaneous development cleaning is as follows. First, the transfer residual toner on the electrophotographic photosensitive member after transfer is charged in the subsequent and subsequent development steps, that is, subsequently, the electrophotographic photosensitive member is charged and exposed to form an electrostatic latent image. Then, a transfer residual toner existing on the surface of the photosensitive member (non-image portion) that should not be developed with toner is collected by the developing device by a fog removal bias during the developing process of the electrostatic latent image. The fog removal bias is a fog removal potential difference Vback which is a potential difference between a DC voltage applied to the developing device and the surface potential of the photoreceptor. According to this method, the transfer residual toner is collected by the developing device and reused for developing the electrostatic latent image in the subsequent steps. Accordingly, waste toner can be eliminated, and maintenance work can be reduced. Further, the cleaner-less configuration is advantageous for reducing the size of the image forming apparatus.

In order to remove and collect the transfer residual toner on the electrophotographic photosensitive member by the simultaneous development cleaning of the developing unit, the charged polarity of the transfer residual toner that is carried to the developing unit after passing through the charging unit must be a normal polarity. There is. It is also necessary that the charge amount be a toner charge amount that can develop the electrostatic latent image on the photoreceptor by the developing means. Reversal toner and toner with an inappropriate charge amount cannot be collected from the electrophotographic photosensitive member to the developing means, and cause a defective image. Thus, for example, devices described in Patent Document 1 and Patent Document 2 have been proposed. In these apparatuses, a brush member is disposed in contact with the electrophotographic photosensitive member on the downstream side of the transfer unit and on the upstream side of the charging unit and collected, and the pattern-like transfer residual toner is dispersed and distributed on the surface of the electrophotographic photosensitive member. And unpatterned. In addition, the charged polarity of the transfer residual toner is charged to the normal polarity so as to be equal to the normal polarity and the charge amount is made uniform. After such a process, the transfer residual toner is returned to the surface of the electrophotographic photosensitive member again.
JP 2001-215798 A JP 2003-162179 A

  However, in recent years, there has been an increasing need for continuously outputting images with high printing ratios such as photographic images, and there are cases where a large amount of toner remains after transfer. The speed of the electrophotographic process is also increasing. In that case, various problems occur in an electrophotographic apparatus provided with brush fibers located on the downstream side of the transfer unit and upstream of the charging unit and in contact with the surface of the electrophotographic photosensitive member. That is, a defective image due to residual toner or an electrophotographic apparatus using a contact charging method may cause toner adhesion to the charging means.

  An object of the present invention is made in view of the above problems, and is an electrophotographic apparatus having brush fibers located on the downstream side of a transfer unit and on the upstream side of a charging unit and in contact with the surface of the electrophotographic photosensitive member. In other words, contamination of defective images and charging means is suppressed.

  The present inventors have found that the above-mentioned problems can be improved by forming a plurality of controlled fine concave portions on the surface of the electrophotographic photosensitive member, and the present invention has been achieved.

  That is, the present invention provides an electrophotographic photosensitive member, a charging unit that charges the electrophotographic photosensitive member, an exposure unit that forms an electrostatic latent image on the electrophotographic photosensitive member that has been charged, and the electrostatic latent image. Developing means for developing the toner from the toner, transfer means for transferring the toner image to the transfer material, located downstream of the transfer means and upstream of the charging means, abutting on the surface of the electrophotographic photosensitive member, After collecting the transfer residual toner, an electrophotographic apparatus comprising brush fibers for applying the transfer residual toner to the surface of the electrophotographic photosensitive member again, the electrophotographic photosensitive member having a surface layer And the depth Rv of the concave portion is 0.3 μm or more and 2.0 μm or less, and the length of the concave portion in the longitudinal direction of the electrophotographic photosensitive member is The relationship between the shaft diameter La and the brush longest diameter Lc is expressed by the following equation (1).

The minor axis diameter of the surface of the concave portion is smaller than the weight average particle diameter of the toner, and the number of concave portions is 60 or more per 100 μm square. The developing means also serves as a cleaning means for collecting toner remaining on the surface of the electrophotographic photosensitive member after being transferred to the transfer material.

  The concave portion is formed by processing by excimer laser irradiation. Alternatively, the concave portion is formed by press-contacting a mold having an uneven shape on the surface. Alternatively, the concave portion is formed by a method of dew condensation on the surface when forming the surface layer of the electrophotographic photosensitive member.

  The reason why the surface shape of the electrophotographic photosensitive member of the present invention is effective is that the end portion of the brush fiber vibrates finely due to the concave shape portion of the electrophotographic photosensitive member, so that the transfer residual toner can be easily taken into the brush. It is presumed that the effect of dispersing and distributing the pattern-like transfer residual toner on the surface of the photosensitive member to make it non-patterned or making the charge amount of the transfer residual toner uniform is improved. As a result, it is considered that the toner adhesion to the defective image and the charging means due to the transfer residual toner is suppressed.

  Further, in the electrophotographic apparatus using the cleanerless system in which the developing unit collects the residual toner after the transfer, the present invention is likely to cause a defective image or contamination of the charging device due to the residual transfer toner. It is more suitable for a less-type electrophotographic apparatus.

  According to the present invention, in an electrophotographic apparatus having brush fibers located on the downstream side of the transfer unit and on the upstream side of the charging unit and in contact with the surface of the electrophotographic photosensitive member, an image having a high printing ratio is continuously output at high speed. Even in this case, contamination of defective images and charging means can be suppressed.

  The electrophotographic apparatus of the present invention will be described in detail with reference to the drawings.

  The electrophotographic photosensitive member in the present invention has a plurality of independent concave portions on the surface layer. And the depth Rv of this concave shape part is 0.3 micrometer or more and 2.0 micrometers or less. Further, the relationship between the long axis diameter La of the concave portion in the longitudinal direction of the electrophotographic photosensitive member and the brush longest diameter Lc satisfies the following formula (1).

  Further, the minor axis diameter of the surface of the concave portion is smaller than the weight average particle diameter of the toner, and the number of concave portions is 60 or more per 100 μm square.

  When the depth Rv of the concave portion is 0.3 μm or more, the effect of the present invention is easily obtained, which is preferable. By forming the concave portion on the surface of the electrophotographic photosensitive member, the tip of the brush fiber in contact with the photosensitive member vibrates, and it is considered that the effect of the present invention is obtained. Therefore, when the depth of the concave portion is less than 0.3 μm, vibration of the brush fiber tip cannot be sufficiently obtained, which is not preferable. On the other hand, if the thickness exceeds 2.0 μm, a problem of appearing as white streaks on the halftone image occurs due to rubbing with the brush member in repeated use, and therefore Rv is preferably 2.0 μm or less.

  Moreover, it is preferable that the major axis diameter La in the longitudinal direction of the electrophotographic photosensitive member of the concave portion satisfies the formula (1). Here, 0.3 in the formula (1) is the minimum depth of the concave shape portion depth Rv, and the left term of the formula (1) is the photosensitivity required for the brush fiber tip portion to enter the concave shape portion. It means the minimum length of the long axis diameter La in the body longitudinal direction. When La satisfies the formula (1), it is considered that the effect of the present invention can be obtained when the tip of the brush fiber in contact with the photosensitive member vibrates. The maximum diameter of the major axis diameter La is more preferably 20 μm or less. This is considered to be because by increasing the number of concave portions on the surface of the photoreceptor, the contact area between the toner and the surface of the photoreceptor is reduced, the transfer efficiency is improved, and the effects of the present invention are more easily obtained. . Further, it is preferable that the minor axis diameter in the surface portion of the concave portion is smaller than the weight average particle diameter of the toner. This is because when the toner is smaller than the weight average particle diameter, the contact area between the toner and the photoreceptor surface is small, and the toner is easily taken into the brush fiber. Further, by setting the number of concave portions to 60 or more per 100 μm square, the proportion of the area of the concave portions in the surface portion of the photosensitive member is increased, so that the effect of the present invention can be easily obtained.

  FIG. 1 shows an example of the surface of an electrophotographic photosensitive member having a plurality of independent concave portions, and the shape of the surface and cross section of the specific shape of each concave portion. As shown in FIG. 1B, various shapes such as a circle, an ellipse, a square, a rectangle, a triangle, and a hexagon can be formed on the surface of each concave portion. Further, as shown in FIG. 1-c, the cross-sectional shape has a triangle, a quadrangle, a polygonal edge, a continuous wave shape, a part of the triangle, a quadrilateral, a polygonal edge. Alternatively, various shapes can be formed, such as a composite of curves.

  The plurality of concave portions formed on the surface of the electrophotographic photosensitive member may all have the same shape, size and depth, or may be a combination thereof.

  Next, the short axis diameter will be described. First, the short axis diameter in each concave shape is defined as the length of the minimum straight line among the straight lines crossing each concave opening as shown in FIG. For example, the diameter of a circle is used, the shorter diameter of an ellipse, and the shorter of a diagonal line of a rectangle. In measuring the minor axis diameter, for example, as shown in FIG. 1-c-3, when the boundary between the concave portion and the flat portion is not clear, the smooth surface before roughening is taken into consideration after taking the cross-sectional shape into consideration. As a reference, the minimum length on the concave surface is defined as the minor axis diameter as shown in the figure. Furthermore, when the smooth surface before roughening is unclear as shown in FIG. 1-c-5, a center line is provided in the cross-sectional views of adjacent recesses to define the minor axis diameter. By statistically processing the short axis diameter of each concave shape per unit area thus obtained, the average value is defined as the short axis diameter of the concave portion in the present invention.

  Also, the diameter in the longitudinal direction of the electrophotographic photosensitive member is defined as the length of the maximum straight line among the straight lines crossing in the longitudinal direction of each concave opening electrophotographic photosensitive member, similarly to the short axis diameter.

  In the present invention, the arrangement of each concave shape is arbitrary and can be optimized.

  In the present invention, a commercially available laser microscope can be used for measurement of the concave portion on the surface of the electrophotographic photosensitive member. For example, the following devices and analysis programs attached to the devices can be used. KEYENCE ultra-deep shape measurement microscopes VK-8550 and VK-9000. Surface shape measuring system Surface Explorer SX-520DR manufactured by Ryoka System. Scanning confocal laser microscope OLS3000 manufactured by Olympus Corporation. Real color confocal microscope Oplitex C130 manufactured by Lasertec Co., Ltd. Using these laser microscopes, it is possible to measure the number of concave portions in a visual field, the short axis diameter of each concave portion, and the long axis diameter in the longitudinal direction at a predetermined magnification. Note that observation and measurement using an optical microscope, an electron microscope, an atomic force microscope, a scanning probe microscope, or the like can also be used.

  Further, the weight average particle diameter of the toner in the present invention can be suitably measured by a pore electrical resistance method. In the present invention, Coulter Multisizer II (manufactured by Coulter, Inc.) is used to measure the weight average particle diameter of the toner. As the electrolytic solution, a 1% NaCl aqueous solution prepared using primary sodium chloride may be used. For example, ISOTON R-II (manufactured by Coulter Scientific Japan) may be used. As a measurement method, 0.3 ml of a surfactant (preferably alkylbenzene sulfonate) is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution, and 2 to 20 mg of a measurement sample is further added. The electrolyte solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the volume and number distribution of the toner are measured by the measuring device to calculate the volume distribution and the number distribution. (D4) (The median value of each channel is used as a representative value for each channel). When the weight average particle size is larger than 6.0 μm, the particle size of 2 to 60 μm is measured using a 100 μm aperture, and when the weight average particle size is 3.0 to 6.0 μm, the 50 μm aperture is used. Measure 1-30 μm particles. When the weight average particle size is less than 3.0 μm, particles of 0.6 to 18 μm are measured using a 30 μm aperture.

  Further, the longest brush diameter in the present invention is defined as the average value of the maximum thickness of the brush portion in contact with the electrophotographic photosensitive member of one brush fiber.

  Next, a method for forming the surface shape of the electrophotographic photosensitive member according to the present invention will be described. The surface shape forming method is not particularly limited as long as it can satisfy the above-described requirements for the concave shape portion, and examples thereof include processing by excimer laser irradiation. Excimer laser is laser light emitted in the following steps. First, a mixed gas of a rare gas such as Ar, Kr, or Xe and a halogen gas such as F or Cl is excited and coupled by applying energy by discharge, electron beam, X-ray, or the like. Thereafter, excimer laser light is emitted when dissociating by falling to the ground state.

Examples of the gas used in the excimer laser include ArF, KrF, XeCl, and XeF, and any of them may be used, and KrF and ArF are particularly preferable. As a method for forming the recess, a mask in which a laser beam blocking portion a and a laser beam transmitting portion b are appropriately arranged as shown in FIG. 2 is used. Only the laser beam that has passed through the mask is condensed by the lens and irradiated onto the workpiece, so that a recess having a desired shape and arrangement can be formed. Since a large number of dents within a certain area can be machined instantly regardless of the shape and area of the dents, the process is short. Laser irradiation using a mask processes several mm ² to several cm ² per irradiation. In laser processing, as shown in FIG. 3, first, the workpiece is rotated by a workpiece rotating motor d. While rotating, the workpiece moving device e shifts the laser irradiation position in the axial direction of the workpiece, whereby a dent can be efficiently formed over the entire surface of the workpiece. The depth of the dent can be adjusted within the desired range depending on the irradiation time and the number of irradiation times of the laser beam. According to the present invention, it is possible to realize rough surface machining with high controllability of the size, shape, and arrangement of the recesses, and with high accuracy and high flexibility. In addition, the electrophotographic photoreceptor according to the present invention may be subjected to the above-described processing using the same mask pattern, and thereby the roughness of the entire surface of the electrophotographic photoreceptor is increased. Further, as shown in FIG. 4, a mask pattern may be formed so as to form an array in which both of the recess forming portion h and the recess non-forming portion g exist on an arbitrary circumferential line of the electrophotographic photosensitive member.

  As a method for forming the surface shape of the electrophotographic photosensitive member according to the present invention, in addition to the above, there is a pressure contact processing method in which a mold having a predetermined uneven shape is pressed against the surface of the electrophotographic photosensitive member to transfer the shape.

  FIG. 5 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. After the predetermined mold B is attached to the pressure device A that can be repeatedly pressed and released, the shape transfer is performed by bringing the mold B into contact with the electrophotographic photosensitive member C at a predetermined pressure. Thereafter, the pressurization is once released and the electrophotographic photosensitive member C is rotated, and then the pressurization and the shape transfer process are performed again. By repeating this process, it is possible to form a predetermined concave portion over the entire circumference of the electrophotographic photosensitive member.

  For example, as shown in FIG. 6, first, a predetermined mold B having an entire circumference of the electrophotographic photosensitive member C is attached to the pressure device A. After that, by rotating and moving the electrophotographic photosensitive member while applying a predetermined pressure to the electrophotographic photosensitive member C, it is possible to form a predetermined concave portion over the entire circumference of the electrophotographic photosensitive member. As another example, a sheet-like mold may be sandwiched between a roll-shaped pressurizing device and an electrophotographic photosensitive member, and surface processing may be performed while feeding the mold sheet.

  The mold or the electrophotographic photosensitive member may be heated for the purpose of efficiently transferring the shape. The material, size, and shape of the mold itself can be selected as appropriate. Examples of the material include the following. Metal or resin film with fine surface processing, silicon wafer patterned surface with resist, resin film with fine particles dispersed, resin film with a predetermined fine surface shape, metal coated, etc. An example of the mold shape is shown in FIG.

  Further, for the purpose of imparting pressure uniformity to the electrophotographic photosensitive member, it is also possible to install an elastic body between the mold and the pressure device.

  Further, as a method for forming the surface shape of the electrophotographic photosensitive member according to the present invention, a method for forming a surface in which the surface is condensed at the time of forming the surface layer of the electrophotographic photosensitive member can be mentioned.

  The formation method performed by condensation on the surface when forming the surface layer of the electrophotographic photosensitive member includes the following steps. First, for a surface layer containing a binder resin and a specific aromatic organic solvent, wherein the content of the aromatic organic solvent is 50% by mass to 80% by mass with respect to the total solvent mass in the coating solution for the surface layer A coating solution is prepared, and the coating solution is applied. Subsequently, the support body coated with the coating liquid is held, and the surface of the support body coated with the coating liquid is condensed. Thereafter, the support is heat-dried to produce a surface layer in which independent concave portions are formed on the surface.

  The step of condensing the surface of the support indicates that the support coated with the surface layer coating liquid is held for a certain period of time in an atmosphere where the surface of the support is condensed. The dew condensation in this surface forming method means that droplets are formed on the support coated with the surface layer coating liquid by the action of water. The conditions for dew condensation on the surface of the support are affected by the relative humidity of the atmosphere holding the support and the volatilization conditions of the coating solution solvent (for example, heat of vaporization). However, since the surface layer coating liquid contains an aromatic organic solvent in an amount of 50% by mass or more based on the total solvent mass, there is little influence of the volatilization condition of the coating liquid solvent, and the relative humidity of the atmosphere holding the support is reduced. Depends mainly on. The relative humidity at which the surface of the support is condensed is 40% to 100%. Furthermore, the relative humidity is preferably 70% or more. In the support holding process, it is sufficient if there is a time required for forming droplets by condensation. From the viewpoint of productivity, it is preferably 1 second to 300 seconds, and more preferably about 10 seconds to 180 seconds. Relative humidity is important for the step of holding the support, but the atmospheric temperature is preferably 20 ° C. or higher and 80 ° C. or lower.

  In addition, by the heat drying step, droplets generated on the surface by the support holding step can be formed as concave portions on the surface of the electrophotographic photosensitive member. In order to form a concave portion with high uniformity, quick drying is important, and thus heat drying is performed. It is preferable that the drying temperature in a drying process is 100 to 150 degreeC. The drying process time for drying by heating only needs to be a time for removing the solvent in the coating solution coated on the support and the water droplets formed by the dew condensation process. The drying process time is preferably 20 minutes to 120 minutes, and more preferably 40 minutes to 100 minutes.

  Due to the surface forming method in which the surface is dewed when the surface layer of the electrophotographic photosensitive member is formed as described above, independent concave portions are formed on the surface of the electrophotographic photosensitive member. The surface formation method that causes the surface to condense when forming the surface layer of the electrophotographic photosensitive member is a method of forming droplets formed by the action of water by using a solvent having a low affinity for water and a binder resin to form concave portions. It is a method of forming. Since the individual shapes of the concave portions formed on the surface of the electrophotographic photosensitive member produced by this manufacturing method are formed by the cohesive force of water, the concave portions are highly uniform. Since this manufacturing method is a manufacturing method that undergoes a step of removing droplets from a state in which the droplets or droplets are sufficiently grown, the concave portion on the surface of the electrophotographic photosensitive member is, for example, a droplet shape or a honeycomb. A concave portion having a shape (hexagonal shape) is formed. The droplet-shaped concave portion is a concave portion that is observed in a circular shape or an elliptical shape, for example, when observing the surface of the photoreceptor, and is, for example, a partial circle or a partial portion when observing a cross section of the electrophotographic photosensitive member. The concave-shaped part observed elliptically is shown. In addition, the honeycomb-shaped (hexagonal) concave-shaped portion is a concave-shaped portion formed by, for example, close-packed droplets on the surface of the electrophotographic photosensitive member. Specifically, in observation of the surface of the electrophotographic photosensitive member, for example, the concave portion is circular, hexagonal or hexagonal with rounded corners, and in observation of the cross section of the electrophotographic photosensitive member, for example, partial circle or A concave shaped part such as a prism is shown.

  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 photosensitive member of the present invention will be described.

  The electrophotographic photoreceptor of the present invention is preferably an electrophotographic photoreceptor having a support and an organic photosensitive layer (hereinafter also simply referred to as “photosensitive layer”) provided on the support. In general, a cylindrical organic electrophotographic photosensitive member having a photosensitive layer formed on a cylindrical support is widely used, but a belt shape or a sheet shape is also possible.

  The photosensitive layer is separated into a charge generating layer containing a charge generating material and a charge transporting layer containing a charge transporting material even if it is a single layer type photosensitive layer containing the charge transporting material and the charge generating material in the same layer. The laminated photosensitive layer may be used. From the viewpoint of electrophotographic characteristics, a laminated photosensitive layer is preferable. The laminated photosensitive layer has a normal layer type photosensitive layer laminated in the order of the charge generation layer and the charge transport layer from the support side, and a reverse layer type photosensitive layer laminated in the order of the charge transport layer and the charge generation layer from the support side. However, a normal photosensitive layer is preferred from the viewpoint of electrophotographic characteristics. Further, the charge generation layer may have a stacked structure, and the charge transport layer may have a stacked structure. Furthermore, it is possible to provide a protective layer on the photosensitive layer for the purpose of improving durability.

  The support may be anything that exhibits conductivity (conductive support). For example, a metal (alloy) support such as iron, copper, gold, silver, aluminum, zinc, titanium, lead, nickel, tin, antimony, indium, chromium, aluminum alloy, and stainless steel can be used. Moreover, the said metal support body and plastic support body which have a layer in which aluminum, an aluminum alloy, an indium oxide tin oxide alloy etc. were formed into a film by vacuum deposition can also be used. In addition, a support in which conductive particles such as carbon black, tin oxide particles, titanium oxide particles, and silver particles are impregnated into plastic or paper together with an appropriate binder resin, or a plastic support having a conductive binder resin, etc. Can also be used.

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

  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, etc., and covering scratches on the support. It may be provided.

  The conductive layer can be formed using a conductive layer coating solution in which carbon black, a conductive pigment or a resistance adjusting pigment is dispersed and / or dissolved in a binder resin. You may add the compound which carries out hardening polymerization by the heating or radiation irradiation to the coating liquid for conductive layers. The surface of a conductive layer in which a conductive pigment or a resistance adjusting pigment is dispersed tends to be roughened.

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

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

  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. . Alternatively, particles of metal oxide such as zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, tin-doped indium oxide, antimony or tantalum-doped tin oxide may be used. These may be used alone or in combination of two or more. When two or more types are used in combination, they may be simply mixed, or may be in the form of a solid solution or fusion.

  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 the purpose of improving the adhesion of the photosensitive layer, improving the coating property, improving the charge injection property from the support, and protecting the photosensitive layer from electrical breakdown.

  Examples of the material for the intermediate layer include the following. Polyvinyl alcohol, poly-N-vinylimidazole, polyethylene oxide, ethyl cellulose, ethylene-acrylic acid copolymer, casein, polyamide, N-methoxymethylated 6 nylon, copolymer nylon, glue and gelatin, etc. The intermediate layer can be formed by applying a coating solution for intermediate layer obtained by dissolving these materials in a solvent and drying it.

  The thickness of the intermediate layer is preferably 0.05 to 7 μm, and more preferably 0.1 to 2 μm.

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

  Examples of the charge generating material used in the photosensitive layer of the present invention include the following. Selenium-tellurium, pyrylium, thiapyrylium dyes, phthalocyanine pigments having various central metals and various crystal systems (α, β, γ, ε, X type, etc.), anthanthrone pigments, dibenzpyrenequinone pigments, Pyrantron pigment. In addition, azo pigments such as monoazo, disazo, trisazo, indigo pigments, quinacridone pigments, asymmetric quinocyanine pigments, quinocyanine pigments, amorphous silicon, and the like. 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 of the present invention include the following. Pyrene compounds, N-alkylcarbazole compounds, hydrazone compounds, N, N-dialkylaniline compounds, diphenylamine compounds, triphenylamine compounds, triphenylmethane compounds, pyrazoline compounds, styryl compounds, stilbene compounds, and the like.

  When functionally separating the photosensitive layer into a charge generation layer and a charge transport layer, the charge generation layer is formed as follows. First, the charge generation material is dispersed by a method using a homogenizer, an ultrasonic dispersion, a ball mill, a vibration ball mill, a sand mill, an attritor, or a roll mill together with a binder resin and a solvent in an amount of 0.3 to 4 times (mass ratio). It can be formed by applying the coating solution for charge generation layer thus obtained and drying it. The charge generation layer may be a vapor generation film of a charge generation material.

  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 the coating solution. 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.

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

  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, more preferably 10 to 35 μm.

  Moreover, in order to express more durable performance, a surface layer can also be comprised with curable resin.

  The charge transport layer itself can be composed of a curable resin, and a curable resin layer can be formed on the above-described charge transport layer as a second charge transport layer or a protective layer. The characteristics required for the curable resin layer are both the strength of the film and the charge transport capability, and are generally composed of a charge transport material and a polymerized or crosslinkable monomer or oligomer.

  Examples of the charge transport material include known hole transport compounds and electron transport compounds. Examples of the polymerizable or crosslinkable monomer or oligomer include a chain polymerization material having an acryloyloxy group or a styrene group, and a sequential polymerization material having a hydroxyl group, an alkoxysilyl group, an isocyanate group, or the like. From the viewpoint of the obtained electrophotographic characteristics, versatility, material design, manufacturing stability, etc., a combination of a hole transporting compound and a chain polymerization material is preferable, and both the hole transporting group and the acryloyloxy group are molecules. A system for curing the compound contained therein is particularly preferred.

  As the curing means, known means such as heat, light, and radiation can be used. In the case of the charge transport layer, the thickness of the hardened layer is preferably 5 to 50 μm, more preferably 10 to 35 μm, as described above. In the case of the second charge transport layer or protective layer, the thickness is preferably 0.1 to 20 μm, and more preferably 1 to 10 μm.

  Various additives can be added to each layer of the electrophotographic photoreceptor of the present invention. Examples of additives include deterioration inhibitors such as antioxidants and ultraviolet absorbers, and lubricants such as fluorine atom-containing resin particles.

  Next, an example of the electrophotographic apparatus of the present invention will be described with reference to FIG.

  In FIG. 8, the electrophotographic photoreceptor 1 rotates in the direction of the arrow and is charged by the charging means 2. Thereafter, the image information is written as an electrostatic latent image by the exposure means 3, and the electrostatic latent image is visualized as a toner image by the developing means 4. The visualized toner image on the surface of the photoconductor is transferred onto the transfer material P by the transfer means 5. The untransferred toner remaining on the surface of the photoconductor without being transferred by the transfer means is made uniform by the brush fiber member 7 disposed in contact with the electrophotographic photoconductor 1 and charged by the brush fiber member 6 with the same polarity as the charge. The Then, after being charged through the above-described charging means and exposure means, they are again used for development or collected by the developing device.

  In the present invention, a plurality of components such as the electrophotographic photosensitive member 1, the charging unit 2, the developing unit 4, and the brush fiber member 7 described above may be integrally combined as a process cartridge. By doing so, the process cartridge may be configured to be detachable from a main body of an electrophotographic apparatus such as a copying machine or a laser beam printer.

  In the charging means 2, a method of charging the electrophotographic photosensitive member without contact with the electrophotographic photosensitive member, such as corona charging or proximity charging, or charging by contacting a conductive roller, brush, blade, or the like with the electrophotographic photosensitive member. A contact charging method or an injection charging method is used. From the viewpoint that contamination of the charging means can be prevented as an effect of the present invention, a charging means of a contact charging system or an injection charging system is more preferable.

  Further, the image exposure irradiated from the exposure means 3 is reflected light or transmitted light from a document when the electrophotographic apparatus is a copying machine or a printer. Alternatively, the light is irradiated by scanning a laser beam, driving an LED array, driving a liquid crystal shutter array, and the like performed by reading a document with a sensor and converting the signal into a signal.

  For the developing means 4, jumping development, two-component contact development, one-component contact development, or the like is used.

The brush members 6 and 7 may have a fixed brush shape or a brush rotating body shape. The fibers of the brush part are made by adding carbon or metal powder to fibers such as nylon, rayon, acrylic and polyester to control the resistance value. The maximum brush diameter is preferably 100 μm or less and the density is preferably 1 to 500,000 / inch ² or more so that the surface of the photosensitive drum and the transfer residual toner can be uniformly contacted. The brush member can be thrust with respect to the photosensitive member in the longitudinal direction to make the potential imparting property more uniform. Further, a bias can be applied even when grounding.

  Now, embodiments of the present invention will be described in detail. However, the present invention is not limited to these examples.

  First, the overall configuration of the electrophotographic apparatus of the present invention used in the embodiments will be described with reference to FIGS.

  The full-color laser printer shown in FIG. 10 is a full-color laser printer using a transfer type electrophotographic process, a contact charging method, a reverse development method, and a maximum sheet passing size of A3 size. The four-drum printer has a plurality of process cartridges 8 and continuously multiple transfers once onto an intermediate transfer belt 9 as a second image carrier to obtain a full color print image. The endless intermediate transfer belt 9 is suspended from a drive roller 9e, a tension roller 9f, and a secondary transfer counter roller 10a, and rotates in the direction of the arrow in the figure. Four process cartridges 8 are arranged in series with the intermediate transfer belt 9 in the order of yellow, magenta, cyan, and black.

  Hereinafter, the process cartridge 8 will be described with reference to FIG.

  In the process cartridge 8 for developing each color toner, reference numeral 1 denotes a rotating drum type electrophotographic photosensitive member as an image carrier. The outer shape is 30 mm, the longitudinal length is 370 mm, and it is driven to rotate in the direction of the arrow with a process speed of 250 mm / second around the central support shaft.

As the contact charging means, a voltage under a predetermined condition is applied to the charging roller 2, and the surface of the electrophotographic photosensitive member 1 is uniformly charged with a negative polarity. The charging roller 2 has a longitudinal length of 320 mm, and has a three-layer structure in which a lower layer 2b, an intermediate layer 2c, and a surface layer 2d are sequentially laminated from the bottom around the outer periphery of a core metal (support member) 2a. The lower layer 2b is a foamed sponge layer for reducing charging noise. The intermediate layer 2c is a resistance layer for obtaining a uniform resistance as the entire charging roller. The surface layer 2d is a protective layer provided to prevent leakage even if the electrophotographic photoreceptor 1 has a defect such as a pinhole. The charging roller 2 of this example uses a stainless steel round bar with a diameter of 6 mm as the core metal 2 a, carbon is dispersed in the fluororesin as a surface layer, the outer diameter as a roller is 14 mm, and the roller resistance is 10 ⁴ Ω to 10 ^7. Ω.

  The charging roller 2 is configured such that both ends of the cored bar 2a are rotatably held by bearing members and are urged toward the electrophotographic photosensitive member 1 by a pressing spring so as to be applied to the surface of the electrophotographic photosensitive member 1. It is in pressure contact with a predetermined pressing force. Then, it rotates following the rotation of the electrophotographic photosensitive member 1. Then, a predetermined vibration voltage (bias voltage Vdc + Vac) obtained by superimposing an AC voltage of frequency f on a DC voltage from the power source 20 is applied to the charging roller 2 through the core metal 2a, whereby the rotating electrophotographic photosensitive member 1 is rotated. The peripheral surface is charged to a predetermined potential.

  In this embodiment, a DC voltage: −500 V, an AC voltage; a frequency f = 1500 Hz, a peak-to-peak voltage Vpp = 2000 V, and a vibration voltage in which a sine wave is superimposed, and the peripheral surface of the electrophotographic photosensitive member 1 is −500 V ( The contact charging treatment is uniformly applied to the dark potential Vd).

  In FIG. 9, the charging roller cleaning member 2f is a flexible cleaning film. The cleaning film 2f is arranged in parallel to the longitudinal direction of the charging roller 2 and fixed at one end to a support member 2g that reciprocates a certain amount in the longitudinal direction. And is arranged to form a contact nip. The support member 2g is driven to reciprocate by a certain amount in the longitudinal direction via a gear train by a drive motor of the printer, and the charging roller surface layer 2d is rubbed with the cleaning film 2f. As a result, contaminants on the surface 2d of the charging roller (fine powder toner, external additives, etc.) are removed.

  After the charging process is uniformly performed at a predetermined polarity and potential by the charging roller 2, the following process is performed. A laser beam scanner using a semiconductor laser is used as an exposure device, and a laser beam modulated in response to an image signal sent from a host device such as an image reading device (not shown) to the printer side is output to produce an electrophotographic photosensitive device. The uniformly charged surface of the body 1 is subjected to laser scanning exposure. As a result of the laser scanning exposure, the potential of the surface of the photoconductor 1 irradiated with the laser light decreases, and an electrostatic latent image corresponding to the image information subjected to the scanning exposure is formed on the surface of the electrophotographic photoconductor 1. In this embodiment, the exposure part potential is set to -150V.

  Next, the electrostatic latent image is developed by the first developer 4 (yellow developer) with yellow toner as the first color.

  As the toner of this example, a pulverized toner having a weight average particle diameter of 7.5 μm was used. As the pulverized toner, a binder resin, a release agent, a charge control agent, and a colorant were melt-kneaded with a Henschel mixer and a heating roll, then cooled and solidified, and then subjected to thermal spheronization treatment, and silica added externally. .

  In FIG. 10, the yellow image formed on the electrophotographic photosensitive member 1 enters the primary transfer nip portion with the intermediate transfer belt 9. In the transfer nip portion, a transfer roller 9 g is brought into contact with the back side of the intermediate transfer belt 9. The transfer roller 9g has primary transfer bias sources 9a to 9d so that a bias can be applied independently at each port. The intermediate transfer belt 9 first transfers yellow at the first color port, and then sequentially transfers magenta, cyan, and black colors at each port from the electrophotographic photosensitive member 1 corresponding to each color through the same process described above. . The four-color full-color image formed on the intermediate transfer belt 9 is then collectively transferred to the transfer material P sent from the paper feed roller 12 by the secondary transfer roller 10, and is fused and fixed by a fixing device (not shown). Get a print image.

  The secondary transfer residual toner remaining on the intermediate transfer belt 9 is subjected to blade cleaning by the intermediate transfer belt cleaner 11 to prepare for the next image forming process.

In FIG. 9, a brush member 6 that charges the transfer residual toner and a brush member 7 that equalizes the transfer residual toner are in contact with the electrophotographic photosensitive member 1. Both use brush members made of conductive fibers in this embodiment. Specifically, the brush members 6 and 7 are obtained by providing brush portions 61 and 71 on horizontally long electrode plates 62 and 72. The brush portions 61 and 71 are disposed in contact with and fixedly supported on the surface of the electrophotographic photosensitive member 1. In this embodiment, both the brush portions 61 and 71 are made of rayon fiber containing carbon, the brush has a longest diameter of 40 μm, 100,000 pieces / inch ² , a length of a bristle length of 5 mm, and the resistance of the brush is 6 × 10. ³ Ω · cm. These brush members 6 and 7 are brought into contact with the surface of the electrophotographic photosensitive member 1 so that the brush portions 61 and 71 have a penetration amount of 1 mm, and the contact nip width with the electrophotographic photosensitive member 1 is 5 mm. did.

  In this embodiment, a negative voltage is applied from the power source 21 to the brush member 6 that charges the untransferred toner. Further, an AC voltage on which a DC voltage is superimposed is applied from a power source 22 to the brush member 7 that uniformizes the transfer residual toner.

  A DC bias of −700 V was applied to the brush member 6, and the bias applied to the brush member 7 was a sine wave, Vpp = 400 V, frequency = 1150 Hz, and Vdc = + 250 V.

(Electrophotographic photosensitive member production example 1)
Here, a first example of an electrophotographic photosensitive member according to the present invention was produced.

  First, a solution composed of the following materials was dispersed with a ball mill for about 20 hours. 60 parts by mass of titanium oxide powder having a coating film of tin oxide doped with antimony, 60 parts by mass of titanium oxide powder, 70 parts by mass of resol type phenol resin, 50 parts by mass of 2-methoxy-1-propanol and 50 parts by mass of methanol Department. The titanium oxide powder having a coating film of tin oxide doped with antimony is trade name: Kronos ECT-62 and manufactured by Titanium Industry Co., Ltd. The titanium oxide powder is trade name: titone SR-1T and manufactured by Sakai Chemical Co., Ltd. The resol type phenolic resin is trade name: Phenolite J-325, manufactured by Dainippon Ink & Chemicals, Inc., and has a solid content of 70%. The average particle size of the filler of the dispersion made of such a material was 0.25 μm.

  The dispersion prepared in this manner was applied by dipping onto a 30 mmφ × 370 mm long aluminum cylinder, dried and cured for 30 minutes in a hot air drier adjusted to 150 ° C., and a conductive film having a film thickness of 15 μm. A layer was formed.

  Next, a solution obtained by dissolving 10 parts by mass of copolymer nylon resin and 30 parts by mass of methoxymethylated nylon resin in a mixed solution of 500 parts by mass of methanol and 250 parts by mass of butanol was dip-coated on the above-described conductive layer. Then, it was put into a hot air dryer adjusted to 100 ° C. for 10 minutes and dried by heating to form an undercoat layer having a thickness of 0.5 μm. Here, the copolymerized nylon resin is a trade name: Amilan CM8000, manufactured by Toray Industries, Inc. The methoxymethylated nylon resin is trade name: Toresin EF30T and manufactured by Teikoku Chemical Industry Co., Ltd.

  Next, a mixed solution made of the following materials was dispersed in a sand mill for 10 hours using glass beads having a diameter of 1 mm, and then 110 parts by mass of ethyl acetate was added to prepare a charge generation layer coating solution. 4 parts by mass of a hydroxygallium phthalocyanine pigment, 2 parts by mass of a polyvinyl butyral resin, and 90 parts by mass of cyclohexanone. Here, the hydroxygallium phthalocyanine pigment has strong peaks at 7.4 ° and 28.2 ° with a Bragg angle of 2θ ± 0.2 ° in a CuKa characteristic X-ray diffraction spectrum. Moreover, the said polyvinyl butyral resin is a brand name: ESREC BX-1, and is the product made by Sekisui Chemical Co., Ltd. This coating solution was dip-coated on the undercoat layer described above, placed in a hot air dryer adjusted to 100 ° C. for 10 minutes, and dried by heating to form a charge generation layer having a thickness of 0.2 μm.

  Next, 9 parts by mass of a compound represented by the following structural formula as a charge transport material,

  1 part by mass of a compound represented by the following structural formula,

12.5 parts by mass of a polyarylate resin (weight average molecular weight 100000) having a repeating structural unit represented by the following formula as a binder resin,

0.025 parts by mass of a silicone-modified resin (weight average molecular weight 5000) represented by the following formula:

Was dissolved in a mixed solution of 40 parts by mass of dimethoxymethane and 60 parts by mass of monochlorobenzene.

  This solution was applied onto the charge generation layer by a dip coating method and dried at 120 ° C. for 1 hour to form a charge transport layer having a thickness of 20 μm, thereby producing an electrophotographic photosensitive member.

(Electrophotographic photosensitive member production example 2)
Here, a second example of an electrophotographic photosensitive member according to the present invention was produced.

  First, a solution made of the following materials was dispersed with a ball mill for about 20 hours. 60 parts by mass of titanium oxide powder having a coating film of tin oxide doped with antimony, 60 parts by mass of titanium oxide powder, 70 parts by mass of resol type phenol resin, 50 parts by mass of 2-methoxy-1-propanol and 50 parts by mass of methanol Department. The titanium oxide powder having a coating film of tin oxide doped with antimony is trade name: Kronos ECT-62 and manufactured by Titanium Industry Co., Ltd. The titanium oxide powder is trade name: titone SR-1T and manufactured by Sakai Chemical Co., Ltd. The resol type phenolic resin is trade name: Phenolite J-325, manufactured by Dainippon Ink & Chemicals, Inc., and has a solid content of 70%. The average particle size of the filler of the dispersion made of such a material was 0.25 μm.

  The dispersion prepared in this manner was applied by dipping onto a 30 mmφ × 370 mm long aluminum cylinder, dried and cured for 30 minutes in a hot air drier adjusted to 150 ° C., and a conductive film having a film thickness of 15 μm. A layer was formed.

  Next, a solution obtained by dissolving 10 parts by mass of copolymer nylon resin and 30 parts by mass of methoxymethylated nylon resin in a mixed solution of 500 parts by mass of methanol and 250 parts by mass of butanol was dip-coated on the above-described conductive layer. And it put into the hot-air dryer adjusted to 100 degreeC for 10 minutes, heat-dried, and formed the undercoat layer of the film thickness of 0.5 micrometer. Here, the copolymerized nylon resin is a trade name: Amilan CM8000, manufactured by Toray Industries, Inc. The methoxymethylated nylon resin is trade name: Toresin EF30T, manufactured by Teikoku Chemical Industry Co., Ltd.

  Next, a mixed solution made of the following materials was dispersed in a sand mill for 10 hours using glass beads having a diameter of 1 mm, and then 110 parts by mass of ethyl acetate was added to prepare a charge generation layer coating solution. Hydroxygallium phthalocyanine pigment 4 parts by mass, polyvinyl butyral resin (mixed solution consisting of 2 parts by mass and cyclohexanone 90 parts by mass. Here, the hydroxygallium phthalocyanine pigment has a Bragg angle 2θ ± 0.2 ° in a CuKa characteristic X-ray diffraction spectrum. In addition, the polyvinyl butyral resin is trade name: ESRECK BX-1, which is manufactured by Sekisui Chemical Co., Ltd. It was dip-coated on the undercoat layer, placed in a hot air drier adjusted to 100 ° C. for 10 minutes, and dried by heating to form a charge generation layer having a thickness of 0.2 μm.

  Next, 45 parts by weight of the compound represented by Chemical Formula 1, 5 parts by weight of the compound represented by Chemical Formula 2 and 50 parts by weight of bisphenol Z-type polycarbonate resin in Electrophotographic Production Example 1 were replaced by 320 parts by weight of monochlorobenzene and 50 parts by weight of dimethoxymethane. It was prepared by dissolving in part. The charge transport layer coating solution thus obtained is dip-coated on the above-described charge generation layer, put into a hot air dryer adjusted to 100 ° C. for 60 minutes, and dried by heating to a film thickness of 15 μm. The first charge transport layer was formed. Here, the bisphenol Z-type polycarbonate resin is trade name: Iupilon Z400, and is manufactured by Mitsubishi Engineering Plastics.

Next, 0.1 part by mass of a fluorine atom-containing resin as a dispersant was dissolved in a mixed liquid of 35 parts by mass of 1,1,2,2,3,3,4-heptafluorocyclopentane and 35 parts by mass of 1-propanol. Thereafter, 2 parts by mass of a tetrafluoroethylene resin powder was added as a lubricant, and the mixture was uniformly dispersed by performing treatment three times at a pressure of 59 N / mm ² with a high-pressure disperser. The fluorine atom-containing resin is trade name: GF-300 and manufactured by Toagosei Co., Ltd. The 1,1,2,2,3,3,4-heptafluorocyclopentane is a product name: Zeolora H, and is manufactured by Nippon Zeon Co., Ltd. The tetrafluoroethylene resin powder is trade name: Lubron L-2 and is manufactured by Daikin Industries, Ltd. The high-pressure disperser is trade name: Microfluidizer M-110EH, manufactured by Microfluidics, USA. It was filtered under pressure with a 10 μm PTFE membrane filter to prepare a lubricant dispersion. Thereafter, 25 parts by mass of a hole transporting compound represented by the following structural formula

Was added to the above-mentioned lubricant dispersion and subjected to pressure filtration with a PTFE 5 μm membrane filter to prepare a second charge transport layer coating solution as a curable surface layer. Using this coating solution, a second charge transport layer was applied as a curable surface layer on the first charge transport layer by a dip coating method. Thereafter, an electron beam was irradiated in nitrogen under the conditions of an acceleration voltage of 120 kV and a dose of 1.5 Mrad (1.5 × 10 ⁴ Gy). Subsequently, a heat treatment was performed for 90 seconds under the condition that the temperature of the photosensitive member was 120 ° C. The oxygen concentration at this time was 10 ppm. Further, the photoconductor was heat-treated in the air at 100 ° C. for 20 minutes in the air to form a curable surface layer having a thickness of 5 μm.

Example 1
In the apparatus shown in FIG. 6, the shape transfer mold shown in FIG. 11 was placed on the electrophotographic photosensitive member obtained in Preparation Example 1 to perform surface processing. The longest diameter in the longitudinal direction of the photoreceptor in this mold was 7.0 μm, the minor axis diameter was 7.0 μm, the height was 3.0 μm, and the interval between the shapes was 3.0 μm. The temperature of the electrophotographic photosensitive member and the mold during processing was controlled at 150 ° C., and shape transfer was performed by rotating the photosensitive member in the circumferential direction while applying pressure at a pressure of 4.9 MPa (50 kg / cm ² ).

  The surface shape of the obtained photoreceptor was enlarged and observed with a laser microscope (VK-9500 manufactured by Keyence Corporation). Then, as shown in FIG. 12, it was found that recesses having a longest longest diameter La: 7.0 μm, a short shaft diameter: 7.0 μm, and a depth Rv: 1.5 μm were formed at intervals of 3.0 μm. . The number per 100 μm square was 100.

  Further, the obtained electrophotographic photosensitive member was mounted on the full-color electrophotographic apparatus of FIG. 10 in an environment of 32 ° C./80%, and the image was evaluated. First, a lattice image, a solid white image, and a halftone image were output in order, and the presence or absence of fog due to a transfer residual ghost and charging failure was evaluated. Next, we conducted a one-sheet intermittent paper endurance experiment with 10,000 sheets of an image with a printing ratio of 50%. After endurance, a grid image, a solid white image, and a halftone image were output in order, and a transfer residual ghost and fogging due to poor charging and scratches. The presence or absence of white streaks and the like and the surface state of the electrophotographic photosensitive member were confirmed. The results are shown in Table 1 below.

(Example 2)
In the apparatus shown in FIG. 6, the shape transfer mold height F shown in FIG. 11 was changed to 0.6 μm and surface processing was performed on the electrophotographic photosensitive member obtained in Preparation Example 2. The temperature of the electrophotographic photosensitive member and the mold during processing was controlled at 120 ° C., and shape transfer was performed by rotating the photosensitive member in the circumferential direction while applying pressure at a pressure of 4.9 MPa (50 kg / cm ² ).

  The surface shape of the obtained photoreceptor was enlarged and observed with a laser microscope (VK-9500 manufactured by Keyence Corporation). Then, as shown in FIG. 12, it was found that recesses having a longest longest diameter La: 7.0 μm, a short shaft diameter: 7.0 μm, and a depth Rv: 0.3 μm were formed at intervals of 3.0 μm. . The number per 100 μm square was 100.

  The obtained photoreceptor was mounted on the full-color electrophotographic apparatus shown in FIG. 10 in the same manner as in Example 1 and evaluated. The results are shown in Table 1 below.

(Example 3)
The electrophotographic photosensitive member obtained in Preparation Example 2 was subjected to surface processing using the apparatus shown in FIG. 6 by installing the shape transfer mold shown in FIG. In this mold, the longest diameter in the longitudinal direction of the photoreceptor is 7.0 μm, the short axis diameter is 7.0 μm, the maximum height is 1.5 μm, and the interval between the shapes is 3.0 μm. The temperature of the electrophotographic photosensitive member and the mold during processing was controlled at 120 ° C., and shape transfer was performed by rotating the photosensitive member in the circumferential direction while applying pressure at a pressure of 4.9 MPa (50 kg / cm ² ).

  The surface shape of the obtained photoreceptor was enlarged and observed with a laser microscope (VK-9500 manufactured by Keyence Corporation). Then, as shown in FIG. 14, it was found that the longest diameter in the longitudinal direction La: 7.0 μm, the minor axis diameter: 7.0 μm, and the depth Rv: 2.0 μm were formed at intervals of 3.0 μm. . The number per 100 μm square was 100.

  The obtained photoreceptor was mounted on the full-color electrophotographic apparatus shown in FIG. 10 in the same manner as in Example 1 and evaluated. The results are shown in Table 1 below.

Example 4
With respect to the electrophotographic photosensitive member obtained in Preparation Example 2, the shape transfer mold shown in FIG. 15 was installed in the apparatus shown in FIG. 6 to perform surface processing. In this mold, the longest diameter in the longitudinal direction of the photoreceptor is 12.0 μm, the short axis diameter is 7.0 μm, the height is 0.6 μm, and the interval between each shape is 4.0 μm on the long axis side and the short axis The side was 3.0 μm. The temperature of the electrophotographic photosensitive member and the mold during processing was controlled at 120 ° C., and shape transfer was performed by rotating the photosensitive member in the circumferential direction while applying pressure at a pressure of 4.9 MPa (50 kg / cm ² ).

  The surface shape of the obtained photoreceptor was enlarged and observed with a laser microscope (VK-9500 manufactured by Keyence Corporation). Then, as shown in FIG. 16, the longest diameter in the longitudinal direction La: 12.0 μm, the minor axis diameter: 7.0 μm, and the depth Rv: 0.3 μm are the photoreceptor longitudinal direction side 4.0 μm, minor axis side 3. It was found that the film was formed at intervals of 0.0 μm. The number per 100 μm square was 60.

  The obtained photoreceptor was evaluated in the same manner as in Example 1 except that the diameter of the brush member was changed to 60 μm in the full-color electrophotographic apparatus of FIG. The results are shown in Table 1 below.

(Example 5)
A recess was formed in the outermost surface layer of the electrophotographic photosensitive member obtained in Preparation Example 2 using a KrF excimer laser (wavelength λ = 248 nm, pulse width = 17 ns). At this time, as shown in FIG. 17, a quartz glass mask having a pattern in which circular laser beam transmitting portions b having a diameter of 30 μm are arranged at intervals of 10 μm is used, and irradiation energy is set to 0.9 J / cm ² once. The irradiation area per irradiation was 1.4 mm square. a is a laser beam shielding part. As shown in FIG. 3, the workpiece was rotated, and irradiation was performed while shifting the irradiation position in the axial direction.

  The surface shape of the obtained photoreceptor was enlarged and observed with a laser microscope (VK-9500 manufactured by Keyence Corporation). Then, as shown in FIG. 18, it was found that the longest longest diameter La: 6.0 μm, the short shaft diameter: 6.0 μm, and the depth Rv: 1.0 μm were formed at intervals of 2.0 μm. . The number per 100 μm square was 144.

  The obtained photoreceptor was evaluated in the same manner as in Example 1 except that the diameter of the brush member was changed to 20 μm in the full-color electrophotographic apparatus of FIG. The results are shown in Table 1 below.

(Example 6)
In the same manner as in Preparation Example 1, a conductive layer, an intermediate layer, and a charge generation layer were formed.

  Next, in a mixed solvent of 550 parts of monochlorobenzene, 280 parts of methylal and 20 parts of water, 70 parts of the hole transporting compound of Chemical Formula 1 and a polyarylate resin having a repeating structural unit represented by Chemical Formula 3 as a binder resin ( Weight average molecular weight 100,000). And the coating liquid for surface layers containing a charge transport substance was prepared. The step of preparing the surface layer coating solution was performed at a relative humidity of 45% and an ambient temperature of 25 ° C.

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

  180 seconds after the end of the coating process, the cylindrical support in which the coating liquid for the surface layer is coated in the apparatus for holding the cylindrical support whose relative humidity is 50% and the atmospheric temperature is 25 ° C. The body was held for 180 seconds.

  Sixty seconds after the end of the cylindrical support holding step, the cylindrical support was placed in a blower dryer that had been heated to 120 ° C. in advance, and the drying step was performed for 60 minutes.

  In this manner, an electrophotographic photosensitive member having a plurality of concave-shaped portions and a charge transport layer having a thickness of 20 μm as a surface layer was produced.

  The surface shape of the obtained electrophotographic photosensitive member was enlarged and observed with a laser microscope (VK-9500, manufactured by Keyence Corporation). Then, it was found that the longest longest diameter La: 7.0 μm, the short axis diameter: 7.0 μm, and the depth Rv: 1.5 μm were formed at intervals of 1.0 μm. The number per 100 μm square was 144.

  The obtained photoreceptor was mounted on the full-color electrophotographic apparatus shown in FIG. 10 in the same manner as in Example 1 and evaluated. The results are shown in Table 1 below.

(Comparative Example 1)
In Example 1, the surface processing and evaluation of the electrophotographic photosensitive member were performed in the same manner as in Example 1 except that the surface processing of the produced electrophotographic photosensitive member was not performed. The results are shown in Table 1 below.

(Comparative Example 2)
The shape of the shape transfer mold shown in FIG. 11 of Example 1 is the same as that of Example 1 except that the longest diameter in the longitudinal direction of the photoreceptor is changed to 9.0 μm and the minor axis diameter is changed to 9.0 μm. Photoconductor surface processing and evaluation were performed.

  The surface shape of the obtained photoreceptor was enlarged and observed with a laser microscope (VK-9500 manufactured by Keyence Corporation). Then, it was found that the longest diameter La: 9.0 μm, the minor axis diameter: 9.0 μm, and the depth Rv: 1.5 μm were formed at intervals of 3.0 μm. The number per 100 μm square was 64. The results are shown in Table 1 below.

(Comparative Example 3)
The shape of the shape transfer mold shown in FIG. 11 of Example 1 is the same as that of Example 1 except that the longest diameter in the longitudinal direction of the photoreceptor is changed to 5.0 μm and the minor axis diameter is changed to 5.0 μm. Photoconductor surface processing and evaluation were performed.

  The surface shape of the obtained photoreceptor was enlarged and observed with a laser microscope (VK-9500 manufactured by Keyence Corporation). Then, it was found that the longest longest diameter La: 5.0 μm, the short axis diameter: 5.0 μm, and the depth Rv: 1.5 μm were formed at intervals of 3.0 μm. The number per 100 μm square was 144. The results are shown in Table 1 below.

(Comparative Example 4)
In the shape of the shape transfer mold shown in FIG. 11 of Example 1, the surface processing and evaluation of the electrophotographic photosensitive member were performed in the same manner as in Example 1 except that the interval between the concave portions was changed to 7.0 μm. .

  The surface shape of the obtained photoreceptor was enlarged and observed with a laser microscope (VK-9500 manufactured by Keyence Corporation). Then, it was found that the longest diameter in the longitudinal direction La: 7.0 μm, the minor axis diameter: 7.0 μm, and the depth Rv: 1.5 μm were formed at intervals of 7.0 μm. The number per 100 μm square was 49. The results are shown in Table 1 below.

(Comparative Example 5)
In the shape of the shape transfer mold shown in FIG. 11 of Example 1, the surface processing and evaluation of the electrophotographic photosensitive member were performed in the same manner as in Example 1 except that the depth of the concave portion was changed to 5.0 μm. .

  The surface shape of the obtained photoreceptor was enlarged and observed with a laser microscope (VK-9500 manufactured by Keyence Corporation). Then, it was found that recesses having a longest diameter La: 7.0 μm, a short axis diameter: 7.0 μm, and a depth Rv: 2.5 μm were formed at intervals of 3.0 μm. The number per 100 μm square was 100. The results are shown in Table 1 below.

  As described above, according to the present invention, in an electrophotographic apparatus having brush fibers located on the downstream side of the transfer unit and on the upstream side of the charging unit and in contact with the surface of the electrophotographic photosensitive member, an image with a high printing ratio is obtained. Can be prevented from being contaminated with defective images and charging means even when the image is continuously output at high speed.

It is a figure which shows the example of the concave shape part of the electrophotographic photoreceptor surface in this invention. It is a figure which shows the example (partial enlarged view) of the arrangement pattern of the mask of this invention. It is a figure which shows the example of the schematic of the laser processing apparatus of this invention. It is a figure which shows the example (partial enlarged view) of the dent arrangement | sequence pattern of the photoreceptor outermost surface obtained by this invention. It is a figure which shows the example of the schematic of the press-contact shape transfer processing apparatus by the mold in this invention. It is a figure which shows another example of the schematic of the press-contact shape transfer processing apparatus by the mold in this invention. It is a figure which shows the example of the shape of the mold in this invention. It is a schematic sectional drawing of the electrophotographic apparatus of this invention. 1 is a schematic cross-sectional view of a process cartridge of a full-color electrophotographic apparatus according to an embodiment of the present invention. 1 is a schematic cross-sectional view of a full-color electrophotographic apparatus according to an embodiment of the present invention. It is a figure which shows the shape of the mold used in Example 1,2. It is a figure which shows the arrangement pattern (partial enlarged view) of the concave-shaped part of the electrophotographic photoreceptor surface obtained by Example 1,2. FIG. 6 is a view showing the shape of a mold used in Example 3. FIG. 10 is a diagram showing an array pattern (partially enlarged view) of concave portions on the surface of an electrophotographic photosensitive member obtained in Example 3. It is a figure which shows the shape of the mold used in Example 4. FIG. FIG. 6 is a diagram showing an array pattern (partially enlarged view) of concave portions on the surface of an electrophotographic photosensitive member obtained in Example 4; It is a figure which shows the example (partial enlarged view) of the arrangement pattern of the mask used in Example 5. FIG. FIG. 10 is a diagram showing an array pattern (partially enlarged view) of concave portions on the surface of an electrophotographic photosensitive member obtained in Example 5.

Explanation of symbols

a laser light blocking part b laser light transmitting part c excimer laser light irradiator d work rotating motor e work moving device f electrophotographic photosensitive member g dent non-forming part h dent forming part A pressure device B mold C electrophotographic photosensitive member D Projection diameter in the mold E Convex spacing in the mold F Height of the projection in the mold 1 Electrophotographic photosensitive member 2 Charging means 2a Core metal (support member)
2b Lower layer 2c Intermediate layer 2d Surface layer 2f Charging roller cleaning member 2g Support member 3 Exposure unit 4 Development unit 5 Transfer unit P Transfer material 6 Brush member 61 Brush unit 62 Electrode plate 7 Brush member 71 Brush unit 72 Electrode plate 8 Process cartridge 9 Intermediate transfer belts 9a to 9d Primary transfer bias source 9e Driving roller 9f Tension roller 9g Transfer roller 10 Secondary transfer roller 10a Secondary transfer counter roller 11 Intermediate transfer belt cleaner 12 Paper feed rollers 20, 21, 22 Power supply

Claims (5)

An electrophotographic photosensitive member; a charging unit that charges the electrophotographic photosensitive member; an exposure unit that forms an electrostatic latent image on the electrophotographic photosensitive member that has been charged; and a development that develops the electrostatic latent image from toner Means, a transfer means for transferring the toner image to the transfer material, and a position downstream of the transfer means and upstream of the charging means, contacting the surface of the electrophotographic photosensitive member, and collecting residual toner after transfer. Then, again, an electrophotographic apparatus comprising a brush fiber for applying the transfer residual toner to the surface of the electrophotographic photosensitive member,
The electrophotographic photosensitive member has a plurality of independent concave portions on the surface layer, and the depth Rv of the concave portion is 0.3 μm or more and 2.0 μm or less, and the concave portion has the depth Rv. The relationship between the major axis diameter La in the longitudinal direction of the electrophotographic photosensitive member and the brush longest diameter Lc is expressed by the following equation (1).

And the minor axis diameter of the surface of the concave portion is smaller than the weight average particle diameter of the toner, and the number of concave portions is 60 or more per 100 μm square. .   The electrophotographic apparatus according to claim 1, wherein the developing unit also serves as a cleaning unit that collects toner remaining on the surface of the electrophotographic photosensitive member after being transferred to the transfer material.   The electrophotographic apparatus according to claim 1, wherein the concave portion is formed by processing by excimer laser irradiation.   3. The electrophotographic apparatus according to claim 1, wherein the concave portion is formed by press-contacting a mold having a concavo-convex shape on a surface thereof.   3. The electrophotographic apparatus according to claim 1, wherein the concave portion is formed by a method in which a surface is condensed when a surface layer of the electrophotographic photosensitive member is formed.