JP5105986B2 - Image forming apparatus and process cartridge - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an image forming apparatus exhibiting favorable cleaning performance in a durable lifetime even in various environments from low temperature and low humidity to high temperature and high humidity, and to provide a process cartridge that can be used for the image forming apparatus. <P>SOLUTION: The image forming apparatus includes an electrophotographic photoreceptor and a cleaning means for cleaning off a toner remaining on the electrophotographic photoreceptor with an elastic blade, and is characterized in that: a plurality of concave portions each independent are formed on the surface of the electrophotographic photoreceptor, the area ratio of apertures of the concave portions ranges from 70% to 95%; and the angle of the elastic blade with respect to the electrophotographic photoreceptor at a contact portion between the electrophotographic photoreceptor and the elastic blade is set to from 30&deg; to 80&deg;. The process cartridge is detachably attached to the main body of the image forming apparatus. <P>COPYRIGHT: (C)2009,JPO&amp;INPIT

Description

  The present invention relates to an image forming apparatus in an electrophotographic process such as a copying machine, a laser printer, and a facsimile, and a process cartridge that can be used in the image forming apparatus.

  In general, an electrophotographic system is employed in an image forming apparatus that records an image on a recording medium such as paper, such as a copying machine, a laser printer, and a facsimile. The electrophotographic system forms a latent image on the surface of an image carrier such as a photoconductive photoreceptor, and after developing and transferring toner, cleans the toner remaining on the surface of the image carrier and forms a latent image again. Consists of a series of electrophotographic processes.

  In such an electrophotographic system, the cleaning step is important for obtaining a clear image. As a cleaning method, there is a method in which a cleaning blade is brought into contact with a photosensitive member, a gap between the cleaning blade and the photosensitive member is eliminated, and toner remaining is prevented from being scraped off, thereby scraping off transfer residual toner. It has become mainstream due to advantages such as ease of design.

  As a method of contacting the cleaning blade with the electrophotographic photosensitive member (hereinafter, simply referred to as “photosensitive member” in some cases), depending on the direction in which the air surface of the cleaning blade and the edge of the cut surface are brought into contact with the photosensitive member surface The following two methods are known. FIG. 1 shows a with system in which the cut surface c is installed on the downstream side in the rotational movement direction of the photoconductor, and FIG. 2 shows a counter system in which the cut surface c is installed on the upstream side in the rotational movement direction of the photoconductor. From the viewpoint of cleaning performance, a counter method is generally adopted at present.

  As a material for the cleaning blade, urethane rubber is generally used that has high hardness and high elasticity, and is excellent in wear resistance, mechanical strength, oil resistance, ozone resistance, and the like. However, the friction coefficient between the cleaning blade made of such urethane rubber and the surface of the photoreceptor is very high. For this reason, a powder having a small particle size such as an external additive of toner is actually slidable between the two, and a stable contact of the cleaning blade is realized ( Patent Document 1).

  However, depending on the electrophotographic process, the amount of powder interposed between the cleaning blade and the surface of the photoreceptor may be extremely small. For example, it is considered that the frictional resistance between the cleaning blade and the surface of the photosensitive member is particularly likely to increase during mass printing of a pattern having a low printing density, or during monochromatic continuous printing in a tandem electrophotographic system. Various problems related to cleaning are likely to occur.

  The physical properties of the cleaning blade and the contact method with the photoconductor greatly depend on the ease of cleaning and the surface property of the photoconductor due to the degree of adhesion of the transfer residual toner to the photoconductor. Also, the cleaning performance is greatly affected by physical properties such as toner shape, particle size, and material. Therefore, it is necessary to select a blade suitable for the cleaning property and set an appropriate angle and contact load with respect to the photoreceptor. Therefore, in actual selection and setting of the cleaning blade, the present condition is that the optimum condition is found by repeating trial and error (Patent Document 2).

  For example, in recent full-color image forming apparatuses, the toner particle size and spheroidization are progressing due to the trend toward higher image quality. However, such toner has higher fluidity, so that it is compared with conventional toners. It is said that cleaning is very difficult. Therefore, it is known that it is effective to increase the contact pressure of the cleaning blade or reduce the coefficient of friction on the surface of the photoreceptor.

  In general, in order to obtain good cleaning performance, as shown in FIG. 3, it is known that it is effective to increase the set angle θ1 of the air surface of the cleaning blade with respect to the photoreceptor and to increase the contact pressure. ing. However, in reality, if the contact pressure of the cleaning blade is increased, the frictional force with the photosensitive member increases, and the blade chatters and becomes distorted, which tends to make cleaning impossible. Therefore, the setting angle θ1 between the air surface of the cleaning blade and the photosensitive member is usually set to less than 30 °, preferably 25 ° or less, as shown in FIG. Further, for the purpose of increasing the cleaning angle θ2 with respect to the photoreceptor on the cut surface of the cleaning blade, the material and hardness of the cleaning blade are optimized, and the cleaning angle θ2 is normally set to a value exceeding 60 ° as shown in FIG. Is done. At this time, the cleaning blade comes into contact with the belly, and it is possible to suppress the chattering and wobbling. However, on the other hand, the cleaning performance deteriorates due to the contact pressure being dispersed due to the contact area between the cleaning blade and the photosensitive member being increased or the pressure of the cleaning blade contact portion being tangential to the photosensitive member surface. There is a tendency (Patent Document 3). In addition, there are concerns about the abrasion of the cleaning blade, the increase in rotational driving torque of the photosensitive member, the temperature rise of the photosensitive member, etc. due to the increase in frictional force.

  As means for solving the above problems, a technique is disclosed in which the entire surface of the cleaning blade opposite to the surface facing the photosensitive member is supported by a rigid body (Patent Document 4). According to this method, it is considered that the cleaning blade can be prevented from curling. However, since the entire surface of the blade is fixed to a rigid body, the conventional blade free length is substantially zero, and the freedom of movement of the blade itself is greatly suppressed, so it is considered that stable cleaning performance cannot be obtained. . Further, it is considered that the frictional force between the photosensitive member and the blade is equal to or larger than the conventional one, and it is considered that the above technical problem due to the increase in the frictional force remains unsolved.

  As another solution, a technique for processing the shape of the free length portion and the edge of the cleaning blade to a curved surface is disclosed (Patent Document 5). According to this method, it is said that good cleaning performance can be obtained by suppressing the dispersion of the contact pressure while suppressing the abrasion of the cleaning blade edge. However, in order to achieve a sufficient cleaning performance, a high contact pressure of 3 MPa or more is necessary, and it is considered that the above technical problem due to the increase in the frictional force remains unsolved.

  Furthermore, the actual operating environment, particularly the cleaning performance due to temperature and humidity fluctuations, and the degree of wear of the surface layer of the photoreceptor vary. Therefore, maintaining a stable cleaning performance throughout the durable life of the photoreceptor cannot be solved even when the above-described conventional technology is used.

  On the other hand, for electrophotographic photoreceptors, 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 due to the advantages of low cost and high productivity. An organic electrophotographic photosensitive member is widely used. As an organic electrophotographic photoreceptor, a laminated photosensitive layer comprising a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material, because of the advantages of high sensitivity and diversity of material design The electrophotographic photosensitive member having the above is the mainstream. Examples of the charge generating substance include a photoconductive dye and a photoconductive pigment, and examples of the charge transport substance include a photoconductive polymer and a photoconductive low molecular weight compound.

  Since the electrical and / or mechanical external forces of charging, exposure, development, transfer, and cleaning are directly applied to the surface of the electrophotographic photosensitive member as described above, many problems caused by these external forces occur. Specific examples of problems include a decrease in durability due to the occurrence of scratches and wear on the surface layer, a decrease in transfer efficiency, toner fusion, and image defects due to poor cleaning. These problems are thought to contribute to the surface of the photoreceptor and the cleaning system in many ways. Along with the improvement of the cleaning system described above, improvement of the surface layer has been actively studied as an approach from the photoreceptor side. ing.

  Specifically, for the purpose of increasing the strength of the surface layer and imparting high releasability and slipperiness, it is possible to improve the resin constituting the surface layer and add fillers and water repellent materials from the material side. It is being considered.

  On the other hand, as an improvement from the physical aspect, studies have been made to solve the above-described problems by appropriately roughening the surface layer. Roughening of the surface layer improves the releasability and reduces the frictional force by reducing the contact area when contacting the toner, charging member, transfer member, cleaning member, etc. in contact with the surface layer. There is expected. In particular, since the frictional force between the surface layer and the cleaning blade is particularly large, the problems of the deterioration of the cleaning performance and the durability performance due to the frictional force are as described above. Specific examples of the decrease in durability performance include an increase in the amount of wear on the surface layer due to an increase in frictional resistance and the occurrence of scratches due to local pressure concentration. It is considered that the roughening described above works effectively for these problems.

  These problems on the cleaning blade and the surface of the photoreceptor generally tend to become more prominent as the mechanical strength of the surface layer of the photoreceptor increases and the peripheral surface of the photoreceptor becomes harder to wear. Therefore, it is considered that the roughening of the surface layer is one of the very effective means for improving the adverse effect of increasing the strength by improving the surface layer resin as described above.

As a technique for roughening the surface layer, for example, the following technique is disclosed:
・ Technology for keeping the surface roughness of the photoreceptor (roughness of the peripheral surface) within a specified range and the drying conditions when forming the surface layer to facilitate separation of the transfer material from the surface of the photoreceptor A method of roughening the surface of the photosensitive member into a rough skin shape by controlling (Patent Document 6);
-Technology for roughening the surface of the electrophotographic photoreceptor by incorporating particles in the surface layer (Patent Document 7);
-Technology for roughening the surface of the electrophotographic photosensitive member by polishing the surface of the surface layer using a metal wire brush (Patent Document 8);
-To solve the problem of reversing the cleaning blade and chipping of the edge, which is a problem when used in an electrophotographic apparatus having a specific process speed or higher, using a specific cleaning means and toner. Technology for roughening the surface (Patent Document 9);
-Technology for roughening the surface of the electrophotographic photoreceptor by polishing the surface of the surface layer using a film-like abrasive (Patent Document 10);
A technique for roughening the peripheral surface of the electrophotographic photosensitive member by blasting (Patent Document 11).

  However, details of the shape of the surface of the electrophotographic photosensitive member roughened in this way are not specifically described.

  The above-described roughening by the prior art is required to be further improved from the viewpoint of appropriately roughening the surface layer, although a certain effect is recognized for reducing the frictional force with the cleaning blade described above. In addition, in terms of the surface shape being streaks, irregular shapes or irregularities having size variations, there is a problem of controlling cleaning performance from a microscopic viewpoint and adhesion of developer, paper powder, etc. There is a need for further improvements.

  An electrophotographic photosensitive member having a predetermined dimple shape has been proposed by focusing on control of the surface shape of the electrophotographic photosensitive member and conducting detailed analysis and examination (Patent Document 12). Although this method has found a direction to solve problems such as cleaning performance and rubbing memory, further improvement in performance is required.

  In addition, a technique is disclosed in which the surface of an electrophotographic photosensitive member is compression-molded using a well-shaped stamper with unevenness (Patent Document 13). This technique is more effective in solving the above-mentioned problems from the viewpoint that independent uneven shapes can be formed on the surface of the electrophotographic photosensitive member with good controllability as compared with those disclosed in Patent Documents 1 to 6. It is considered to be appropriate. According to this method, by forming a well-shaped concavo-convex shape having a length or pitch of 10 to 3000 nm on the surface of the electrophotographic photosensitive member, the toner releasability is improved and the nip pressure of the cleaning blade is reduced. Is possible. As a result, it is possible to reduce the wear of the photoreceptor. However, the photoconductor having such a concavo-convex shape differs in the actual operating environment, particularly the cleaning properties due to temperature and humidity fluctuations, and the degree of wear of the surface layer of the photoconductor. In particular, lowering the nip pressure is disadvantageous from the viewpoint of maintaining the cleaning performance for cleaning the toner having a small particle size and high sphericity. For this reason, it is difficult to maintain stable cleaning performance throughout the durable life of the photoreceptor.

  As described above, according to the conventional technology, although certain effects are recognized against various technical issues related to the cleaning performance and the increase in frictional force, in improving the overall performance, There is still room for improvement.

Therefore, it is necessary to develop an image forming apparatus that exhibits good cleaning performance through durability even under various environments.
JP 2004-341190 A Japanese Patent Laying-Open No. 2005-16477 JP 2007-33503 A JP 2007-41417 A JP 2006-195348 A JP-A-53-92133 JP-A-52-26226 JP-A-57-94772 JP-A-1-99060 Japanese Patent Laid-Open No. 2-139666 JP-A-2-150850 International Publication No. 2005/93518 Pamphlet JP 2001-66814 A

  The object of the present invention is, as a result of considering the above-described prior art, can be used in an image forming apparatus that exhibits good cleaning performance through durability even in various environments from low temperature and low humidity to high temperature and high humidity, and the image forming apparatus. A process cartridge is provided.

  As a result of intensive studies, the present inventors have found that the above-mentioned problems can be effectively solved by controlling the shape of the surface of the photoreceptor and the cleaning means, and have reached the present invention.

That is, according to the present invention, the developing means for developing the electrostatic latent image formed on the peripheral surface of the electrophotographic photosensitive member with toner, the electrophotographic photosensitive member, and the peripheral surface of the electrophotographic photosensitive member. In an image forming apparatus having cleaning means for cleaning toner with an elastic blade,
A plurality of independent recesses are formed on the surface of the electrophotographic photosensitive member,
The average value D ′ of the opening major axis diameter of the recess is 0.50 μm or more and 1.50 μm or less, and the average depth H ′ of the recess is 2.00 μm or more and 4.00 μm or less,
The ratio H ′ / D ′ of the average depth H ′ to the average value D ′ of the aperture major axis diameter is 1.53 or more and 4.00 or less,
The opening area ratio of the recess is 80% or more and 90% or less,
The set angle θ1 of the elastic blade with respect to the electrophotographic photosensitive member at the contact portion between the electrophotographic photosensitive member and the elastic blade is 45 ° or more and 70 ° or less,
The cleaning angle θ2 of the cut surface of the elastic blade at the contact portion with respect to the electrophotographic photosensitive member is 20 ° or more and 40 ° or less,
The contact length of the elastic blade in the contact portion in the rotational movement direction of the electrophotographic photosensitive member is 20 μm or more and 30 μm or less,
The contact pressure of the elastic blade on the electrophotographic photosensitive member at the contact portion is 0.6 MPa or more and 2.0 MPa or less,
The elastic blade is in contact with the electrophotographic photosensitive member at a linear pressure of 15 g / cm or more and 40 g / cm or less at the contact portion;
An image forming apparatus is provided in which the elastic blade is a cleaning blade mainly composed of urethane rubber, and the average circularity of the toner is 0.925 or more and 0.981 or less .

Further, according to the present invention, the electrophotographic photosensitive member, the developing means for developing the electrostatic latent image formed on the peripheral surface of the electrophotographic photosensitive member with toner, and the residual on the peripheral surface of the electrophotographic photosensitive member. In a process cartridge that integrally supports a cleaning means for cleaning toner with an elastic blade and is detachable from the image forming apparatus main body,
A plurality of independent recesses are formed on the surface of the electrophotographic photosensitive member,
The average value D ′ of the opening major axis diameter of the recess is 0.50 μm or more and 1.50 μm or less, and the average depth H ′ of the recess is 2.00 μm or more and 4.00 μm or less,
The ratio H ′ / D ′ of the average depth H ′ to the average value D ′ of the aperture major axis diameter is 1.53 or more and 4.00 or less,
The opening area ratio of the recess is 80% or more and 90% or less,
The set angle θ1 of the elastic blade with respect to the electrophotographic photosensitive member at the contact portion between the electrophotographic photosensitive member and the elastic blade is 45 ° or more and 70 ° or less,
The cleaning angle θ2 of the cut surface of the elastic blade at the contact portion with respect to the electrophotographic photosensitive member is 20 ° or more and 40 ° or less,
The contact length of the elastic blade in the contact portion in the rotational movement direction of the electrophotographic photosensitive member is 20 μm or more and 30 μm or less,
The contact pressure of the elastic blade on the electrophotographic photosensitive member at the contact portion is 0.6 MPa or more and 2.0 MPa or less,
The elastic blade is in contact with the electrophotographic photosensitive member at a linear pressure of 15 g / cm or more and 40 g / cm or less at the contact portion;
A process cartridge is provided in which the elastic blade is a cleaning blade mainly composed of urethane rubber, and the average circularity of the toner is 0.925 or more and 0.981 or less .

  According to the present invention, it is possible to provide an image forming apparatus that exhibits stable cleaning performance through durability even under various usage environments from low temperature and low humidity to high temperature and high humidity, and a process cartridge that can be used in the image forming apparatus. .

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<Overall Configuration of Image Copying Apparatus and Process Cartridge>
FIG. 6 is a diagram illustrating an example of a schematic configuration of an image forming apparatus including a process cartridge having an electrophotographic photosensitive member and a cleaning unit of the present invention.

  In FIG. 6, a cylindrical electrophotographic photosensitive member 1 is rotationally driven in a direction of an arrow about a shaft 2 at a predetermined peripheral speed.

  The peripheral surface of the electrophotographic photosensitive member 1 that is driven to rotate is uniformly charged to a predetermined positive or negative potential by a charging unit (primary charging unit: charging roller or the like) 3. Next, exposure light (image exposure light) 4 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 peripheral surface of the electrophotographic photosensitive member 1. The charging unit 3 is not limited to the contact charging unit using a charging roller as shown in FIG. 6, but may be a corona charging unit using a corona charger, or other type of charging unit. Also good.

  The electrostatic latent image formed on the peripheral surface of the electrophotographic photosensitive member 1 is developed with toner of the developing means 5 to become a toner image. Next, the toner image formed and supported on the peripheral surface of the electrophotographic photoreceptor 1 is sequentially transferred onto a transfer material (plain paper, coated paper, etc.) P by a transfer bias from a transfer means (transfer roller, etc.) 6. Go. The transfer material P may be fed from a transfer material supply means (not shown) between the electrophotographic photoreceptor 1 and the transfer means 6 (contact portion) in synchronization with the rotation of the electrophotographic photoreceptor 1. Good. Further, instead of the transfer material, a system in which the toner image is once transferred to an intermediate transfer member or an intermediate transfer belt and then transferred to the transfer material is also possible.

  The transfer material P that has received the transfer of the toner image is separated from the peripheral surface of the electrophotographic photosensitive member 1 and is introduced into the fixing means 8 to receive the image fixing, and is printed out of the apparatus as an image formed product (print, copy). Be out.

  The peripheral surface of the electrophotographic photosensitive member 1 after the toner image is transferred is cleaned by receiving the toner remaining after transfer by a cleaning means (cleaning blade or the like) 7 for cleaning. Further, after being subjected to charge removal processing by pre-exposure light (not shown) from a pre-exposure means (not shown), it is repeatedly used for image formation.

  As shown in FIG. 6, when the charging unit 3 is a contact charging unit using a charging roller, pre-exposure is not necessarily required.

  Among the components of the electrophotographic photosensitive member 1, the charging unit 3, the developing unit 5, the transfer unit 6 and the cleaning unit 7 described above, 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 image forming apparatus main body of a copying machine or a laser beam printer. In FIG. 6, the electrophotographic photosensitive member 1, the charging unit 3, the developing unit 5, and the cleaning unit 7 are integrally supported to form a cartridge, and an image forming apparatus is used using a guide unit 10 such as a rail of the image forming apparatus main body. The process cartridge 9 is detachable from the main body.

<Cleaning configuration>
FIG. 7 is a diagram showing an example of a schematic configuration of the electrophotographic photosensitive member and the cleaning unit according to the present invention.

  The cleaning blade 7a, which is an elastic blade, has a flat plate shape and a thickness of t (mm). The upper portion is held by the blade support sheet metal 7b, and the free length L (mm) is from the blade support sheet metal 7b. It sticks out. The cleaning blade 7 a is in contact with the photoreceptor 1 at a point A on the photoreceptor 1, and the extension line of the blade support sheet metal 7 b at the point where the extension line of the blade support sheet metal 7 b and the photoreceptor 1 intersect with each other on the photoreceptor 1. Is defined as a set angle θ1 with respect to the photosensitive member of the cleaning blade. θ1 is preferably 30 ° or more and 80 ° or less, and more preferably 45 ° or more and 70 ° or less. When θ1 is less than 30 °, the conventional general configuration tends to occur and the effect of the present invention cannot be exhibited. When θ1 exceeds 80 °, the cleaning blade 7a is inverted and the cleaning performance tends to be inferior.

  Further, the angle θ2 formed by the tangent line on the photosensitive member 1 and the extended line of the blade cut surface 7c at the point where the extended line of the blade supporting metal plate 7b intersects the photosensitive member 1 is defined as the cleaning angle. θ2 is preferably 10 ° or more and 60 ° or less. When the set angle θ1 is set within a predetermined range, if θ2 exceeds 60 °, the cleaning blade 7a is deformed and the pressure is dispersed, so that the cleaning performance tends to be lowered. When the angle is less than 10 °, the cleaning blade 7a is reversed and the cleaning performance tends to be inferior.

  The cleaning blade 7a is preferably in contact with the photoreceptor 1 with a linear pressure of 10 g / cm or more and 150 g / cm or less. When the linear pressure is less than 10 g / cm, toner tends to slip through, and when it exceeds 150 g / cm, the above-described problem due to an increase in frictional force tends to occur.

  The contact length in the rotational movement direction of the photosensitive member at the contact portion between the cleaning blade 7a and the photosensitive member 1 is 5 μm to 100 μm, and the contact pressure is 0.5 MPa to 20 MPa. preferable. Further, the contact pressure is more preferably 0.5 MPa or more and 2.0 MPa or less. When the contact length is less than 5 μm, the contact between the cleaning blade and the photosensitive member becomes unstable. On the other hand, when the contact length exceeds 100 μm, the contact pressure is dispersed, so that cleaning failure tends to occur. When the contact pressure is less than 0.5 MPa, the contact between the cleaning blade and the photosensitive member becomes unstable and the toner tends to slip through easily. On the other hand, when the pressure exceeds 20 MPa, the above-described problem due to an increase in frictional force tends to occur.

  The contact length and contact pressure in the rotational movement direction of the photosensitive member at the contact portion between the cleaning blade 7a and the photosensitive member 1 were measured as follows. First, a transparent glass support having the same shape as the support of the photoreceptor in the present invention was prepared, and the photosensitive layer and the protective layer in the present invention were formed on the support. The cleaning blade is brought into contact with this at a predetermined linear pressure, and the contact length is measured by observing the contact portion from the inside of the glass support. From the linear pressure and the contact area, the contact per unit area is measured. The contact pressure was calculated.

  Further, Rz1 (ten-point average surface roughness) of the cleaning blade 7a at the contact portion of the cleaning blade 7a with the photosensitive member 1 is smaller than the surface roughness Rz2 (ten-point average surface roughness) of the photosensitive member. It is preferable. Based on JIS B0601, the surface roughness can be measured with a surface roughness measuring device Surfcoder SE3500 manufactured by Kosaka Laboratories or a laser microscope VK9500 manufactured by Keyence Corporation.

The cleaning blade 7a is preferably an elastic blade mainly composed of urethane rubber, and its physical property value is determined by a measuring method described in JIS-K6301. The cleaning blade preferably has a hardness of 50 to 90 (Shore hardness HS), a 100% modulus of 20 Kgf / cm ^{2 to} 90 Kgf / cm ² and a rebound resilience of 5% to 70%. Further, it is preferable to treat the surface of the cleaning blade with an isocyanate compound on a part including the contact portion of the cleaning blade 7a with respect to the photoreceptor 1 in order to achieve further effects in the present invention. In this surface treatment, an isocyanate compound is reacted with moisture in the air or the polyurethane resin itself on the surface of the polyurethane resin to form a cured layer on the surface of the polyurethane resin.

  Moreover, although the example of the support method and shape of the cleaning blade 7a was shown in FIG. 8, these can be suitably selected according to the system to be used.

  In the present invention, a system for supplying a lubricant to the surface on the electrophotographic photosensitive member may be provided as an auxiliary mechanism for cleaning. Specifically, a system for supplying a lubricant such as a fluorine resin, a silicon resin, or a fatty acid metal salt to the surface of the electrophotographic photosensitive member using a coating mechanism such as a brush provided in or near the cleaning device Is mentioned. Further, a system for supplying the lubricant to the surface of the electrophotographic photosensitive member indirectly can be achieved by using the toner to which the lubricant is externally added.

<Toner and development method>
In the present invention, the shape of the toner is defined by the average circularity.

  The average circularity of the toner is measured using a flow type particle image measuring device “FPIA-2100 type” (manufactured by Sysmex Corporation), and is calculated using the following equation.

  Here, the “particle projected area” is the area of the binarized toner particle image, and the “peripheral length of the particle projected image” is the length of the contour line obtained by connecting the edge points of the toner particle image. Define. In the measurement, the perimeter of the particle image when image processing is performed at an image processing resolution of 512 × 512 (pixels of 0.3 μm × 0.3 μm) is used.

  In the present invention, the circularity is an index indicating the degree of unevenness of the toner particles, and is 1.000 when the toner particles are completely spherical. The more complicated the surface shape, the smaller the circularity.

  The average circularity C, which means the average value of the circularity frequency distribution, is calculated from the following equation, where ci is the circularity (center value) at the dividing point i of the particle size distribution and m is the number of measured particles.

  The “flow type particle image analyzer FPIA-2100”, which is a measuring apparatus used in the present invention, first calculates the circularity of each particle. Thereafter, in calculating the average circularity, the particles are divided into classes in which the circularity of 0.4 to 1.0 is equally divided every 0.01 according to the obtained circularity, and the central value of the division points and the number of measured particles The average circularity is calculated using.

  As a specific measurement method, 10 ml of ion-exchanged water from which impure solids and the like are previously removed is prepared in a container, and a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant therein, and then further measurement is performed. Add 0.02 g of sample and disperse uniformly. As a means for dispersion, an ultrasonic disperser “Tetora 150 type” (manufactured by Nikka Ki Bios Co., Ltd.) is used, and dispersion treatment is performed for 2 minutes to obtain a dispersion for measurement. In that case, it cools suitably so that the temperature of this dispersion may not be 40 degreeC or more. In order to suppress variation in circularity, the installation environment of the apparatus is controlled to 23 ° C. ± 0.5 ° C. so that the in-machine temperature of FPIA-2100 is 26 ° C. or higher and 27 ° C. or lower. Autofocus is performed using 2 μm latex particles every 2 hours.

  To measure the circularity of the toner, the flow type particle image measuring apparatus is used, and the concentration of the dispersion is readjusted so that the concentration of the toner at the time of measurement is 3000 / μl or more and 10,000 / μl or less. More than 1000 particles are measured. After the measurement, using this data, data having an equivalent circle diameter of less than 2 μm is cut to determine the average circularity of the toner.

  Furthermore, “FPIA-2100”, which is a measuring apparatus used in the present invention, improves the magnification of the processed particle image compared to “FPIA-1000” that has been used to calculate the shape of the toner. is doing. Further, the accuracy of toner shape measurement has been improved by improving the processing resolution of the captured image (from 256 × 256 to 512 × 512), thereby achieving more reliable capture of fine particles. Therefore, when it is necessary to measure the shape more accurately, the FPIA 2100 that can obtain information on the shape more accurately is advantageous.

  The average circularity of the toner particles is preferably 0.925 or more and 0.995 or less. If the average circularity is less than 0.925, transfer efficiency (especially multiple transfer or secondary transfer) tends to be low. Conversely, if it exceeds 0.995, the cleaning performance tends to be difficult.

As a developing method used in the image forming apparatus of the present invention,
・ Developing in a non-contact state with respect to the photoreceptor (one-component non-contact development)
・ Developing in contact with the photoreceptor (single component contact development),
A method in which toner particles are mixed with a magnetic carrier as a developer, and the developer is conveyed by magnetic force and developed in contact with a photoreceptor (two-component contact development).
・ Method of developing the above two-component developer in a non-contact state with respect to the photoreceptor (two-component non-contact development)
Any of these can be suitably used.

<Surface shape of photoconductor>
The photoreceptor in the present invention is a photoreceptor in which a plurality of independent recesses are formed on the surface, and the aperture area ratio of the recesses is 70% or more and 90% or less.

  Each independent recess in the present invention refers to a recess that exists in a state where each recess is clearly separated from other recesses.

  FIGS. 9A to 9G show examples of specific shapes of the openings of the respective recesses formed on the surface of the electrophotographic photosensitive member according to the present invention, and FIGS. Shows an example of the cross-sectional shape of each recess. 9A to 9G and FIGS. 10A to 10G, D represents the major axis diameter, and H represents the depth. For example, various shapes such as a circle, an ellipse, a square, a rectangle, a triangle, a quadrangle, and a hexagon shown in FIGS. 9A to 9G can be formed as the shape of the opening of each recess. . Further, as the shape of the cross section of the concave portion, those having edges such as triangles, quadrilaterals, and polygons shown in FIGS. 10A to 10G, corrugations composed of continuous curves, the triangles, quadrilaterals, polygons Various shapes can be formed, such as a part or all of the edges of the edges transformed into curves.

  The plurality of recesses formed on the surface of the electrophotographic photosensitive member may all have the same shape, size and depth, or may have different shapes, sizes and depths. Good.

  As shown in FIGS. 9A to 9G, the opening major axis diameter of each recess is defined as the maximum straight line length among the straight lines crossing the openings of each recess. For example, the diameter is used as the major axis diameter in the case of a circle, the major axis in the case of an ellipse, and the diagonal in the case of a quadrangle. In the measurement of the major axis diameter, for example, when the boundary between the recess and the non-recess is not clear as shown in FIG. The maximum length obtained in the same manner as described above is defined as the major axis diameter. Furthermore, when the flat portion is unclear as shown in FIG. 10 (F), the center line m is provided in the cross-sectional view of the adjacent concave portions to define the major axis diameter.

  The concave portion of the present invention is formed on at least the surface of the electrophotographic photosensitive member. The area of the concave portion on the surface of the photoreceptor may be formed over the entire surface of the photoreceptor, or may be formed on a part of the surface. However, in order to exhibit good performance, it is preferably formed at least on the surface portion in contact with the cleaning blade.

In the present invention, the opening area ratio of the recesses is 70% or more and 95% or less, and preferably 80% or more and 90% or less. When the hole area ratio of the recess is less than 70%, it is difficult to obtain the effect of the present invention. The “opening area ratio of the recesses” refers to the ratio of the total area of the opening of the recesses obtained by the following formula in a 100 μm square area on the surface of the photoreceptor.
{Total area of recess openings / (Total area of recess openings + Total area of non-recesses)} × 100

  In the present invention, the 100 μm square region is a total of 100 regions obtained by dividing the surface of the electrophotographic photosensitive member into four equal parts in the direction of rotation of the photosensitive member and 25 equal parts in a direction perpendicular to the rotational direction of the photosensitive member. Each is set by providing a square area with a side of 100 μm.

  In the present invention, it is preferable that the average value D ′ of the opening major axis diameter of the recess is smaller than 10 μm. When the average value D ′ of the aperture major axis diameter exceeds 10 μm, the effects of the present invention tend not to be obtained. The average major axis diameter D 'is defined as an average value obtained by statistically processing the major axis diameter D of each concave portion per 100 μm square according to the above definition.

  As shown in FIGS. 10A to 10B, the depth H of the concave portion in the present invention is the maximum distance between the opening surface and the deepest portion of the concave portion in the cross section of the concave portion with respect to the major axis diameter D described above. Defined. In the depth measurement, similarly to the measurement of the average major axis diameter, the surface of the electrophotographic photosensitive member is divided into four equal parts in the rotation direction of the photosensitive member and divided into 25 equal parts in the direction perpendicular to the rotation direction of the photosensitive member. In each of the 100 regions obtained in this way, a square region having a side of 100 μm is provided, and the recesses included therein are performed. The average depth H ′ is defined as an average value obtained by statistically processing the depth D of each concave portion per 100 μm square according to the above definition.

  In the present invention, the average depth H ′ of the recesses is preferably 0.1 μm or more, and more preferably 0.5 μm or more. When the average depth H ′ is smaller than 0.1 μm, the effects of the present invention tend not to be obtained.

  Further, the ratio of the depth to the major axis diameter H ′ / D, where D ′ is the average value of the major axis diameter of the opening of the recess and H ′ is the average value of the depth indicating the distance between the deepest part and the aperture surface. It is more preferable that 'is more than 1.0 and 7.0 or less. Within this range, it is possible to suppress an increase in the frictional resistance of the cleaning blade even when the amount of toner is low or when no toner is present.

  In the present invention, the arrangement of the concave portions is arbitrary and can be optimized. Specifically, the recesses may be arranged randomly or may be arranged with regularity. In order to improve the uniformity of the surface with respect to the cleaning performance, it is preferably arranged with regularity.

  In the present invention, the shape of 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.

For example, the following equipment can be used as a laser microscope:
-Ultra-depth shape measurement microscope VK-8550, ultra-depth shape measurement microscope VK-9000 and ultra-depth shape measurement microscope VK-9500 (all manufactured by Keyence Corporation);
-Surface shape measurement system Surface Explorer SX-520DR type machine (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).

For example, the following equipment can be used as the optical microscope:
-Digital microscope VHX-500 and digital microscope VHX-200 (both manufactured by Keyence Corporation);
-3D digital microscope VC-7700 (made by OMRON Corporation).

For example, the following equipment can be used as an electron microscope:
-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 Co., Ltd.);
-Scanning electron microscope SUPERSCAN SS-550 (manufactured by Shimadzu Corporation).

For example, the following equipment can be used as an atomic force microscope:
-Nanoscale hybrid microscope VN-8000 (manufactured by Keyence Corporation);
Scanning probe microscope NanoNavi station (manufactured by SII Nanotechnology Inc.);
-Scanning probe microscope SPM-9600 (manufactured by Shimadzu Corporation).

  Using the microscope, the number of recesses, the major axis diameter, and the depth in the measurement field can be measured with a predetermined magnification. Furthermore, the average major axis diameter, average depth, and aperture area ratio of the recesses per unit area can be obtained by calculation.

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 that time, the magnification of the objective lens may be 50 times, and the field of view may be 100 μm × 100 μm (10000 μm ² ). In this method, the surface of the photoconductor to be measured is divided into four equal parts in the direction of rotation of the photoconductor and divided into 25 equal parts in a direction perpendicular to the direction of rotation of the photoconductor, Measurement is performed by providing a square region having a side of 100 μm.

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

Also, with the same visual field and analysis conditions as described above, the total opening area of the recesses is calculated from the sum of the opening areas of the respective recesses obtained using the particle analysis program, and the area ratio of the opening of the recesses (hereinafter referred to as the following) Or simply referred to as “area ratio”).
{Total opening area of recess / (Total opening area of recess + Total area of non-recessed shape)} × 100]

<Method for Forming Recesses on Surface of Electrophotographic Photoreceptor According to the Present Invention>
The method for forming the recess is not particularly limited as long as it can satisfy the requirements related to the recess, and the following methods (a) to (c) are exemplified.
(A) a method for forming a surface of an electrophotographic photosensitive member by laser light irradiation having an output characteristic having a pulse width of 100 ns (nanoseconds) or less;
(B) A method of transferring a shape by pressing a mold having a predetermined shape against the surface of the electrophotographic photosensitive member,
(C) A method of causing condensation on the surface of the electrophotographic photosensitive member when the surface layer is formed.

  (A) A method of forming a recess by irradiation with laser light 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, or 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, high energy such as discharge, electron beam or X-ray 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 to excite the above elements. And combine them. Thereafter, excimer laser light is emitted when dissociating by falling to the ground state. Examples of the gas used in the excimer laser include ArF, KrF, XeCl, and XeF, and any of them may be used. In particular, KrF or ArF is preferable.

As a method for forming the recess, a mask in which a laser beam blocking portion e and a laser beam transmitting portion f are appropriately arranged as shown in FIG. 11 is used. Only laser light 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 recesses within a certain area can be processed simultaneously instantly regardless of their shape and area, the process can be performed in a short time. Laser irradiation using a mask processes several mm ² to several cm ² per irradiation. In laser processing, as shown in FIG. 12, first, the electrophotographic photosensitive member j is rotated by a workpiece rotating motor h. By rotating the laser irradiation position in the axial direction of the electrophotographic photosensitive member by the work moving device i while rotating, the concave portions can be efficiently formed in the entire surface of the electrophotographic photosensitive member. The depth of the concave portion can be adjusted within a desired range depending on the irradiation time and the number of irradiation times of the laser beam. According to this method, it is possible to realize rough surface processing with high controllability of the size, shape, and arrangement of the recesses, and with high accuracy and high flexibility.

  Further, in the method for forming the recesses on the surface of the electrophotographic photosensitive member by laser irradiation, the above-described method for forming the recesses may be applied to a plurality of parts or the entire surface of the photosensitive member using the same mask pattern. By this method, the concave portions can be uniformly formed on the entire surface of the photoreceptor. As a result, the mechanical load applied to the cleaning blade when used in the image forming apparatus is uniform. Further, as shown in FIG. 13, by forming a mask pattern on an arbitrary circumferential line of the photoconductor so that both the concave portions l and the non-concave portions k exist, the mechanical load applied to the cleaning blade is increased. Can be further prevented.

  Next, (b) a method for forming a recess for transferring a shape by pressing a mold having a predetermined shape against the surface of the electrophotographic photosensitive member will be described.

  FIG. 14 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 II is attached to the pressure device I that can repeatedly press and release, the mold II is brought into contact with the photoconductor III at a predetermined pressure to transfer the shape. Thereafter, the pressurization is once released and the photoreceptor III 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 recess shape over the entire circumference of the photoreceptor.

  Further, as shown in FIG. 15, first, a mold II longer than the entire circumference of the photoreceptor III is attached to the pressure device I. Thereafter, a predetermined dimple shape can be formed over the entire circumference of the photoconductor by rotating and moving the photoconductor while applying a predetermined pressure to the photoconductor III.

  As another example, a sheet-shaped mold may be sandwiched between a roll-shaped pressurizing device and a photoreceptor, and surface processing may be performed while feeding the mold sheet. The mold or the photoconductor may be heated for the purpose of efficiently transferring the shape. The heating temperature of the mold and the photoreceptor is arbitrary as long as the shape of the present invention can be formed, but the temperature (° C.) of the mold at the time of shape transfer is made higher than the glass transition temperature (° C.) of the surface layer on the support. It is preferable to be heated. Furthermore, in addition to heating the mold, the temperature (° C) of the support during shape transfer is controlled to be lower than the glass transition temperature (° C) of the surface layer, which stabilizes the recesses transferred to the surface of the photoconductor. It is preferable when forming it.

  The material, size, and shape of the mold itself can be selected as appropriate. Materials include metal and resin film with fine surface processing, silicon wafers and other surfaces patterned with resist, resin film with fine particles dispersed, and resin film with a predetermined fine surface shape. The thing which was done is mentioned. An example of the mold shape is shown in FIGS.

  In addition, an elastic body can be installed between the mold and the pressure device for the purpose of imparting pressure uniformity to the photoconductor.

  Next, (c) a method of forming a recess by causing condensation on the surface of the electrophotographic photosensitive member when the surface layer is formed will be described.

A method for forming a recess that causes condensation on the surface of the electrophotographic photosensitive member when it is formed is performed as follows.
A preparation process of a surface layer coating solution containing a binder resin and a specific aromatic organic solvent, wherein the content of the aromatic organic solvent is 50% by mass or more and 80% by mass or less,
A coating process for coating the coating liquid;
A support holding step for holding the support coated with the coating solution and causing condensation on the surface of the support coated with the coating solution;
-Independent concave portions are formed on the surface by a drying process in which the support is heated and dried.

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

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

It is important that the surface layer coating solution contains an aromatic organic solvent, but for the purpose of stably forming the recesses, the surface layer coating solution contains an organic material having a higher affinity for water. You may contain a solvent or water in the coating liquid for surface layers. As the organic solvent having high affinity with water, the following solvents are preferable.
・ (Methylsulfinyl) methane (common name: dimethyl sulfoxide),
Thiolane-1,1-dione (common name: sulfolane),
N, N-dimethylcarboxamide,
N, N-diethylcarboxamide,
Dimethylacetamide,
1-methylpyrrolidin-2-one.
These organic solvents can be contained alone or in admixture of two or more.

  The above-mentioned support holding step for causing condensation on the surface of the support is a step for holding the support coated with the surface layer coating liquid for a certain period of time in an atmosphere that causes condensation on the surface of the support. Condensation in this method refers to droplets formed on the surface of a support coated with a surface layer coating solution by the action of water. The conditions that cause dew condensation on the surface of the support are affected by the relative humidity of the atmosphere holding the support and the volatilization conditions (for example, heat of vaporization) of the coating solution solvent. However, since the surface layer coating solution contains 50% by mass or more of the aromatic organic solvent with respect to the total solvent mass, the influence of the volatilization condition of the coating solution solvent is small. Therefore, the occurrence of condensation mainly depends on the relative humidity of the atmosphere holding the support. The relative humidity causing condensation on the surface of the support is 40% or more and 100% or less, but preferably 70% or more. In the support holding process, it is sufficient that the support is held for a time necessary for the formation of droplets due to condensation, but from the viewpoint of productivity, it is preferably 1 second or more and 300 seconds or less, and further 10 It is preferable that it is no less than 180 seconds. Although relative humidity is important for the support holding step, the atmospheric temperature is preferably 20 ° C. or higher and 80 ° C. or lower.

  By the drying step of heating and drying, droplets generated on the surface by the support holding step can be formed as concave portions on the surface of the photoreceptor. In order to form a highly uniform recess, rapid drying is important, and thus heat drying is performed. It is preferable that the drying temperature in a drying process is 100 degreeC or more and 150 degrees C or less. The heat drying is performed for a period of time during which the solvent in the coating solution applied on the support and the droplets formed by the dew condensation process are removed. The drying time is preferably 20 minutes or more and 120 minutes or less, and more preferably 40 minutes or more and 100 minutes or less.

  By the above-described method for forming a concave portion that causes condensation on the surface of the electrophotographic photosensitive member when the surface layer is formed, independent concave portions are formed on the surface of the photosensitive member. This method is a method of forming recesses in droplets formed by the action of water using a solvent having a low affinity with water and a binder resin. Since the individual shapes of the recesses formed on the surface of the electrophotographic photosensitive member by this method are formed by the cohesive force of water, the recesses are highly uniform. In addition, since this method is a manufacturing method in which the droplets or the droplets are sufficiently grown to undergo a step of removing the droplets, the concave portion on the surface of the electrophotographic photosensitive member is, for example, a droplet shape or a honeycomb shape. A (hexagonal) recess is formed. In the observation of the surface of the photosensitive member, the droplet-shaped concave portion is, for example, a circular or elliptical concave portion, and in the observation of the cross section of the photosensitive member, for example, a partial circular shape or a partial elliptical concave portion is indicated. In addition, the honeycomb-shaped (hexagonal) concave portion is, for example, a concave portion formed by close-packing droplets on the surface of the electrophotographic photosensitive member. Specifically, in the observation of the surface of the photosensitive member, for example, the concave portion is a circle, a hexagon or a rounded hexagon, and in the observation of the cross section of the photosensitive member, for example, a concave portion such as a partial circle or a prism is shown. .

  In the present invention, in order to form a desired recess, it is possible to control the solvent type in the surface layer coating liquid, the solvent content, the relative humidity in the support holding process, the holding time, and the heating and drying temperature in the drying process.

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

  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 (functional separation type) photosensitive layer may be used. The electrophotographic photoreceptor according to the present invention is preferably a laminated photosensitive layer from the viewpoint of electrophotographic characteristics. In addition, the laminated type photosensitive layer is a reverse layer type in which the charge transport layer and the charge generation layer are laminated in this order from the support side, even if it is a normal layer type photosensitive layer in which the charge generation layer and the charge transport layer are laminated in this order from the support side. It may be a photosensitive layer. In the electrophotographic photoreceptor according to the present invention, when a laminated photosensitive layer is employed, the charge generation layer may have a laminated structure, and the charge transport layer may have a laminated structure. Further, a protective layer can be provided on the photosensitive layer for the purpose of improving the durability performance.

  As a material for the support, any material that exhibits conductivity (conductive support) may be used. For example, a support made of metal (made of alloy) such as iron, copper, gold, silver, aluminum, zinc, titanium, lead, nickel, tin, antimony, indium, chromium, aluminum alloy, and stainless steel can be given.

  Moreover, the said metal support body and plastic support body which have the layer which formed the film by vacuum deposition of aluminum, an aluminum alloy, and an indium oxide tin oxide alloy can also be used. Also, 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 is provided. It 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.

  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.

  The conductive layer may be formed using a conductive layer coating liquid 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 μm or more and 40 μm or less, more preferably 1 μm or more and 35 μm or less, and even more preferably 5 μm or more and 30 μm or less.

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

  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; those deposited on the surface of plastic particles. Alternatively, zinc oxide, titanium oxide, tin oxide, antimony oxide, indium oxide, bismuth oxide, indium oxide doped with tin, or metal oxide particles of tin oxide doped with antimony or tantalum 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 to improve the adhesion of the photosensitive layer, improve the coating property, improve the charge injection property from the support, and protect the photosensitive layer from electrical breakdown.

Examples of intermediate layer materials include:
Polyvinyl alcohol, poly-N-vinylimidazole, polyethylene oxide, ethyl cellulose, ethylene-acrylic acid copolymer, casein, polyamide, N-methoxymethylated 6 nylon, copolymer nylon, glue and gelatin.
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 μm or more and 7 μm or less, and more preferably 0.1 μm or more and 2 μm or less.

Examples of the charge generating material used in the photosensitive layer in the present invention include the following.
・ Pyrrhilium and thiapyrylium dyes;
-Phthalocyanine pigments having various central metals and various crystal systems (α, β, γ, ε, X type, etc.);
・ Anthanthrone pigments;
・ Dibenzpyrenequinone pigments;
・ Pyrantron pigments;
-Azo pigments such as monoazo, disazo, trisazo;
-Indigo pigments;
・ Quinacridone pigments;
-Asymmetric quinocyanine pigments;
・ Quinocyanine pigments;
・ Amorphous silicon.
These charge generation materials may be used alone or in combination of two or more.

Examples of the charge transport material used in the electrophotographic photoreceptor according to 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.

  When functionally separating the photosensitive layer into a charge generation layer and a charge transport layer, the charge generation layer can be formed by the following method. First, the charge generating material is dispersed by a method using a homogenizer, ultrasonic dispersion, ball mill, vibration ball mill, sand mill, attritor or roll mill together with a binder resin and a solvent having a mass ratio of 0.3 to 4 times the mass. . The charge generation layer coating solution obtained by dispersion is applied. By drying this, a charge generation layer can be formed. 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 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.

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

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

  The 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 order to improve the durability, which is one of the characteristics required for the electrophotographic photoreceptor, in the case of the above-described function-separated photoreceptor, the material design of the charge transport layer serving as the surface layer is important. Examples include using high-strength binder resins, controlling the ratio between plastic charge transport materials and binder resins, and using polymer charge transport materials. It is effective to form the surface layer with a curable resin in order to express the above.

  In the present invention, the charge transport layer itself can be composed of a curable resin. Further, a curable resin layer can be formed on the above-described charge transport layer as the second charge transport layer or the protective layer. The properties 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. In some cases, it is also possible to use conductive fine particles whose resistance is controlled for the purpose of imparting charge transport capability.

  As the charge transport material, known hole transport compounds and electron transport compounds can be used. Examples of the polymerizable or crosslinkable monomer or oligomer include a chain polymerization material having an acryloyloxy group and a styrene group, and a sequential polymerization material having a hydroxyl group, an alkoxysilyl group, and an isocyanate group. From the viewpoint of the obtained electrophotographic characteristics, versatility, material design, and production stability, a combination of a hole transporting compound and a chain polymerization material is preferable. Furthermore, both a hole transporting group and an acryloyloxy group are included in the molecule. A system that cures the compound is particularly preferred.

  As the curing means, known means using heat, light, and radiation can be used. Of these, radiation is preferably used. This is because polymerization by radiation does not particularly require a polymerization initiator. This is because an extremely high purity three-dimensional matrix surface layer can be produced, and an electrophotographic photosensitive member exhibiting good electrophotographic characteristics can be obtained. The said radiation is an electron beam or a gamma ray. When irradiating an electron beam, it can be performed using a scanning type, an electro curtain type, a broad beam type, a pulse type or a laminar type accelerator.

In obtaining an electrophotographic photosensitive member having improved electrical characteristics and durability against mechanical deterioration, it is important to consider the electron beam irradiation conditions. For example, in the present invention, the acceleration voltage is preferably 250 kV or less, more preferably 150 kV or less. The dose is preferably in the range of 1 × 10 ⁴ Gy to 1 MGy, more preferably 5 × 10 ⁵ Gy. When the accelerating voltage exceeds the above, the electrical characteristics are liable to deteriorate. Further, when the dose is less than the above range, the surface layer is not sufficiently cured, whereas when the dose is large, the electrical characteristics are liable to deteriorate.

  Furthermore, in the present invention, heat may be applied during the polymerization reaction with an electron beam in order to further cure the surface layer. As the timing of applying heat, the electrophotographic photosensitive member only needs to be at a constant temperature while radicals are present. Therefore, heating may be performed at any stage before, during, or after electron beam irradiation. The heating temperature may be adjusted so that the temperature of the electrophotographic photosensitive member is from room temperature to 250 ° C. More preferably, it is 50 degreeC or more and 150 degrees C or less. This is because when the temperature is higher than the above range, the material of the electrophotographic photosensitive member is deteriorated. The time for heating depends on the temperature, but is preferably about several seconds to several tens of minutes.

  The atmosphere during irradiation and heating may be any of air, inert gas such as nitrogen and helium, and vacuum. In an inert gas or vacuum is preferable in that radical deactivation due to oxygen can be suppressed.

  In the case of the charge transport layer, the thickness of the curable resin layer is preferably 5 μm or more and 50 μm or less, and more preferably 10 μm or more and 35 μm or less, as described above. In the case of the second charge transport layer or protective layer, the thickness is preferably from 0.1 μm to 20 μm, and more preferably from 1 μm to 10 μm.

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

  In the present invention, a desired recess can be formed by performing the above-described laser processing or press-contact shape transfer processing using a mold on an electrophotographic photosensitive member having a surface layer manufactured by the above-described method. . In addition, when using a method of forming a recess by causing condensation on the surface when forming the surface layer, it is possible to form a desired recess by controlling the method of manufacturing the surface layer as described above. is there.

Hereinafter, the present invention will be described in more detail with reference to specific examples. In the examples, “part” means “part by mass”. Examples 5, 6, 8, 11-16, 21, 22, 24, 25 are referred to as Reference Examples 5, 6, 8, 11-16, 21, 22, 24, 25.

Example 1
An aluminum cylinder having a diameter of 30 mm and a length of 260.5 mm was used as a support (cylindrical support).

next,
・ 60 parts of powder composed of barium sulfate particles with tin oxide coating (trade name: Pastoran PC1, manufactured by Mitsui Mining & Smelting Co., Ltd.)
・ Titanium oxide 15 parts (trade name: TITANIX JR, manufactured by Teika Co., Ltd.)
-43 parts of a resol type phenol resin (trade name: Phenolite J-325, manufactured by Dainippon Ink & Chemicals, Inc., solid content 70% by mass)
・ Silicone oil 0.015 parts (trade name: SH28PA, manufactured by Toray Silicone Co., Ltd.)
・ Silicone resin 3.6 parts (trade name: Tospearl 120, manufactured by Toshiba Silicone Co., Ltd.)
A solution comprising 50 parts of 2-methoxy-1-propanol and 50 parts of methanol was dispersed with a ball mill for about 20 hours to prepare a conductive layer coating material. The conductive layer coating material thus prepared was applied on an aluminum cylinder by a dipping method and cured by heating in an oven at a temperature of 140 ° C. for 1 hour to form a resin layer having a thickness of 15 μm.

next,
-Copolymer nylon resin 10 parts (trade name: Amilan CM8000, manufactured by Toray Industries, Inc.)
-30 parts of methoxymethylated 6 nylon resin (trade name: Toresin EF-30T, manufactured by Teikoku Chemical Co., Ltd.)
A solution obtained by dissolving the above component in a mixed solution of 400 parts of methanol / 200 parts of n-butanol is dip-coated on the resin layer described above, and dried by heating in an oven at a temperature of 100 ° C. for 30 minutes. A 45 μm intermediate layer was formed.

next,
20 parts of hydroxygallium phthalocyanine (crystal form having strong peaks at Bragg angles (2θ ± 0.2 °) of 7.4 ° and 28.2 ° in CuKα characteristic X-ray diffraction)
-0.2 part of calixarene compound represented by the following structural formula (1)

・ 10 parts of polyvinyl butyral (trade name: S-REC BX-1, manufactured by Sekisui Chemical)
-The component of 600 parts of cyclohexanone was 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 dispersion for a charge generation layer. This was applied by a dip coating method and heated and dried in an oven at a temperature of 80 ° C. for 15 minutes to form a charge generation layer having a thickness of 0.17 μm.

Then
70 parts of a hole transporting compound represented by the following structural formula (2)

  100 parts of copolymerized polyarylate resin represented by the following structural formula (3)

(In the above formula (3), copolymerization ratio m: n = 7: 3, weight average molecular weight: 130000)
Was dissolved in a mixed solvent of 600 parts of monochlorobenzene and 200 parts of methylal to prepare a charge transport layer coating material. Using this, a charge transport layer was dip-coated on the charge generation layer, and was heated and dried in an oven at a temperature of 100 ° C. for 30 minutes to form a charge transport layer having a thickness of 15 μm.

<Formation of recesses by mold pressure shape transfer>
For the electrophotographic photosensitive member, in the apparatus having the configuration shown in FIG. 15, the shape transfer mold shown in FIG. 17 (major axis diameter X: 1.50 μm, interval Y: 0.10 μm, height Z: 2 .50 μm hexagonal column shape) was installed and surface processing was performed. The shape of the electrophotographic photosensitive member and the mold is controlled so that the temperature of the surface of the electrophotographic photosensitive member during processing is 120 ° C., and the shape is transferred by rotating the photosensitive member in the circumferential direction while applying a pressure of 2.0 MPa. Was done.

<Observation of formed recesses>
The surface shape of the obtained electrophotographic photosensitive member was enlarged and observed with a Surface Explorer SX-520DR type machine (manufactured by Ryoka System Co., Ltd.). As a result, as shown in FIG. 18, it was found that hexagonal columnar recesses having a major axis diameter of 1.50 μm and a depth of 2.30 μm were formed at intervals of 0.10 μm. Moreover, the opening area ratio of the recess was determined to be 90% from the analysis program.

  Further, the surface roughness Rz2 (10-point average surface roughness) of the photoreceptor was measured according to JIS B0601 using a surf coder SE3500 manufactured by Kosaka Laboratory, and found to be 2.20 μm.

<Method for producing non-magnetic toner 1>
After adding 250 parts of 0.1N-Na ₃ PO ₄ aqueous solution to 405 parts of ion-exchanged water and heating to 60 ° C., 40.0 parts of 1.07N-CaCl ₂ aqueous solution is gradually added to contain calcium phosphate salt. An aqueous medium was obtained.

on the other hand,
-Styrene 80 parts-N-butyl acrylate 20 parts-Divinylbenzene 0.2 part-Saturated polyester resin 4.0 parts (polycondensate of propylene oxide modified bisphenol A and isophthalic acid, Tg = 70 ° C, Mw = 41000, Acid value = 15 mg KOH / g, hydroxyl value = 25)
Negative charge control agent (di-tert-butylsalicylic acid Al compound) 1 part I Pigment Blue 15: 3 6.0 parts was uniformly dispersed and mixed using an attritor (Mitsui Miike Chemical Co., Ltd.) to prepare a monomer composition.

  This monomer composition was heated to a temperature of 60 ° C., and 12 parts of an ester wax mainly composed of behenyl behenate (maximum endothermic peak 72 ° C. during temperature rise measurement in DSC) was added, mixed and dissolved. In this, 3 parts of a polymerization initiator 2,2′-azobis (2,4-dimethylvaleronitrile) [t1 / 2 (half-life) = 140 minutes, at 60 ° C.] was dissolved to obtain a polymerizable monomer composition. A product was prepared.

The polymerizable monomer composition is put into the aqueous medium, and the temperature is 60.5 ° C. and N ₂ atmosphere, and TK type homomixer (Special Machine Industries Co., Ltd.) is used at 10,000 rpm for 15 minutes. Stir and granulate. Thereafter, the mixture was reacted at a temperature of 60.5 ° C. for 6 hours while stirring with a paddle stirring blade. Thereafter, the liquid temperature was raised to 80 ° C., and stirring was further continued for 4 hours. After completion of the reaction, distillation was further performed at a temperature of 80 ° C. for 3 hours, and then the suspension was cooled, and hydrochloric acid was added to dissolve the calcium phosphate salt, followed by filtration and washing to obtain wet toner particles. . Thereafter, the wet particles were dried at 40 ° C. for 12 hours to obtain colored particles (toner particles).

100 parts of the toner particles,
-1.0 part of hydrophobic silica fine particles with a primary particle size of 12 nm (treated with 10% by mass of silicone oil, BET specific surface area value of 130 m ² / g)
-1.5 parts of hydrophobic silica fine particles with a primary particle size of 110 nm (treated with 5% by mass of silicone oil)
And a Henschel mixer (Mitsui Miike Chemical Co., Ltd.) to obtain a non-magnetic toner (cyan toner) 1. The non-magnetic toner 1 had an average circularity of 0.981.

<Evaluation of electrophotographic photoreceptor>
The electrophotographic photosensitive member obtained as described above was mounted on a modified machine of a laser beam printer LBP-5500 manufactured by Canon Inc., and evaluated in the following manner under a 25 ° C./55% RH environment.

A cleaning blade made of polyurethane rubber having a hardness of 77 (Shore hardness HS), a 100% modulus of 50 kgf / cm ² , a rebound resilience of 47%, and a thickness of 5 mm was attached to the cleaning unit shown in FIG. At that time, the setting is performed under the conditions of a set angle θ1: 60 °, a free length L: 5 mm, a cleaning (CLN) angle θ2: 30 °, a contact pressure 1.6 MPa, and a contact length 25 μm with respect to the surface of the electrophotographic photosensitive member. Touched. The surface roughness Rz1 (10-point average surface roughness) of the blade on the contact surface was 0.55 μm when measured according to JIS B0601 using a surf coder SE3500 manufactured by Kosaka Laboratory.

First, the rotating state of the photoconductor in the state where the toner is not inserted and the motor is mounted in this state is evaluated.
◎: Rotation possible ○: Rotation possible but slight blade chatter △: Rotation is possible but blade is swayed ×: Blade is not turned over

  As a result, it has been found that the photosensitive member and the cleaning configuration of the present invention can achieve a good cleaning state even when no toner is present.

Thereafter, a non-magnetic toner 1 was used, and a durability test of 1000 sheets was performed under the condition of intermittent A4 sheet size of 2 sheets. A test chart having a printing ratio of 5% was used. The cleaning blade edge on the downstream side in the rotation direction of the electrophotographic photosensitive member after the endurance was observed to evaluate the toner slipping state due to poor cleaning.
◎: No toner slipping ○: There is very slight toner slipping in part of the longitudinal direction of the electrophotographic photosensitive member △: There is slight toner slipping in the entire longitudinal direction of the electrophotographic photosensitive member, but there is no problem in practical use

  As a result, toner slip-through due to poor cleaning was not observed.

  In addition, the rotational torque of the photoconductor before and after durability was measured by the current value of the motor. The initial torque was the average value of the current from the 5th sheet to the 10th sheet after the start of the durability, and the torque after the durability was the average value of the current during the printing of 5 sheets after 1000 sheets. The initial torque current value at this time was set to 1.0, and the ratio with the torque current value after durability was obtained. The following examples and comparative examples were also normalized by setting the initial torque current value in Example 1 to 1.0. The results are shown in Table 1.

(Examples 2 to 6)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the setting of the cleaning blade was changed as shown in Table 1. The results are shown in Table 1. At the upper and lower limits of the cleaning setting, the cleaning property tended to be somewhat unstable, but good results were shown.

(Example 7)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the shape transfer mold interval Y was changed from 0.10 μm to 0.15 μm. The results are shown in Table 1. Although the torque tended to increase slightly as the area ratio decreased, good cleaning performance was exhibited.

(Example 8)
In Example 1, the electrophotographic photosensitive member was formed in the same manner as in Example 1, except that the shape transfer mold interval Y was changed from 0.10 μm to 0.20 μm to form a concave shape on the surface of the electrophotographic photosensitive member. Was made. The results are shown in Table 1. Although the torque tended to increase as much as the area ratio decreased with respect to Example 7, good cleaning performance was exhibited. Further, when the photosensitive member is rotated without toner, there is a tendency that chatter occurs very slightly.

Example 9
With respect to the photoreceptor contact surface side of the cleaning blade in Example 1, it was immersed in an isocyanate (MDI) bath at 80 ° C. for 30 minutes and then pulled up, and the isocyanate compound and polyurethane resin were reacted in an oven at 130 ° C. for 60 minutes, Surface treated. As a result, a cleaning blade having a hardened layer on the contact surface of the photosensitive member as shown in 7d of FIG. 19 was produced. Evaluation was performed in the same manner as in Example 1 using this cleaning blade. The results are shown in Table 1. Compared to Example 1, the torque was greatly reduced and good cleaning performance was obtained.

(Example 10)
In Example 1, except that the major axis diameter X of the shape transfer mold was changed to 0.50 μm, the interval Y was changed to 0.05 μm, and the height Z was changed to 2.20 μm to form a concave shape on the surface of the electrophotographic photosensitive member. Produced an electrophotographic photoreceptor in the same manner as in Example 1. The results are shown in Table 1. Compared to Example 1, the torque was reduced and good cleaning performance was obtained.

(Example 11)
In Example 10, an electrophotographic photosensitive member was produced in the same manner as in Example 1 except that the shape transfer mold height Z was changed to 4.50 μm to form a concave shape on the surface of the electrophotographic photosensitive member. . The results are shown in Table 1. Compared to Example 1, the initial torque decreased and good cleaning performance was obtained, but the torque tended to increase after durability. As a result of observing the surface of the photoconductor after durability, it was found that the concave shape was partially broken. This is presumably because the mechanical strength of the surface of the photoconductor decreased because the ratio of the depth to the major axis diameter of the concave portion was large.

(Example 12)
In Example 1, evaluation was performed in the same manner as in Example 1 except that the setting of the cleaning blade and the linear pressure were changed as shown in Table 1. The results are shown in Table 1. Although the torque was significantly reduced compared to Example 1, the toner tended to slip through the cleaning blade during durability.

(Example 13)
Example 1 except that the surface of the cleaning blade of the cleaning blade in Example 1 that was in contact with the photosensitive member was rubbed with a polishing tape and the surface roughness Rz1 (10-point average surface roughness) was 2.55 μm. And evaluated in the same manner. The results are shown in Table 1. The torque increased compared to Example 1, and the toner tended to partially pass through the cleaning blade during durability.

(Example 14)
In Example 1, the major axis diameter X of the mold for shape transfer was changed to 5.00 μm, the interval Y was set to 0.30 μm, and the height Z was set to 2.50 μm, and a concave shape was formed on the surface of the electrophotographic photosensitive member. Produced an electrophotographic photoreceptor in the same manner as in Example 1. The results are shown in Table 1. The torque tended to increase compared to Example 1, but good cleaning performance was obtained.

(Example 15)
In Example 14, an electrophotographic photosensitive member was produced in the same manner as in Example 14 except that the cleaning blade having the cured layer of Example 9 was used. The results are shown in Table 1. Compared to Example 14, the torque tended to decrease slightly.

(Example 16)
In Example 15, except that the major axis diameter X of the shape-transfer mold was changed to 10.00 μm, the interval Y was 0.80 μm, and the height Z was 2.50 μm, and a concave shape was formed on the surface of the electrophotographic photosensitive member. Produced an electrophotographic photosensitive member in the same manner as in Example 15. The results are shown in Table 1.

(Example 17)
An electrophotographic photosensitive member was produced in the same manner as in Example 1. For the evaluation, a cleaning machine similar to Example 1 was set using a modified machine of the copying machine GP40 manufactured by Canon Inc. The toner used was a magnetic one-component black toner (average circularity: 0.925). The results are shown in Table 1. Torque and cleaning performance were good, but transfer efficiency tended to decrease due to low circularity.

(Example 18)
In Example 1, the evaluation environment was set to 10 ° C./15% RH, and a durability test of 1000 sheets was performed under the condition of intermittent A4 sheet size of 5 sheets. A test chart having a printing ratio of 5% was used, and only the first sheet was printed out of five sheets intermittently, and the remaining four sheets were solid white images. The results are shown in Table 1. Even in a low temperature and low humidity environment, the torque value was low and good cleaning performance was exhibited.

(Example 19)
In Example 18, the evaluation was performed in the same manner as in Example 18 except that the evaluation environment was 32.5 ° C./85% RH. The results are shown in Table 1. The torque tended to slightly increase with respect to Example 18, but good cleaning performance was exhibited even in a high temperature and high humidity environment.

(Example 20)
In Example 19, evaluation was performed in the same manner as in Example 19 except that the cleaning blade having the cured layer of Example 9 was used. The results are shown in Table 1. Compared to Example 19, the torque was significantly reduced and good cleaning performance was exhibited.

(Example 21)
In Example 1, the evaluation was made in the same manner as in Example 1 except that the toner was changed to the nonmagnetic toner 2 shown below. The results are shown in Table 1. The torque at the time of endurance was low and good, but since the circularity was very high, partial slipping in the toner cleaning tended to occur.

<Method for producing non-magnetic toner 2>
In non-magnetic toner production example 1, colored particles (toner particles) after drying are classified by an air classifier (Elbow Jet Lab EJ-L3, manufactured by Nittetsu Mining Co., Ltd.) to adjust the particle size. Produced a nonmagnetic toner (cyan toner) 2 in the same manner as in Nonmagnetic Toner Production Example 1. The average circularity of the nonmagnetic toner 1 was 0.996.

(Example 22)
Evaluation was made in the same manner as in Example 9 except that a cleaning blade having a hardened layer was used and changed as shown in Table 1. As a result, the torque tended to increase slightly, but it showed good cleaning performance.

(Example 23)
Similar to Example 1, the layers up to the charge generation layer were formed. Next, instead of the copolymer polyarylate resin represented by the above structural formula (3), a polycarbonate resin (trade name: Iupilon Z400, manufactured by Mitsubishi Engineering Plastics Co., Ltd.) is used, and the charge transport has a thickness of 10 μm. A layer was formed.

  Next, a coating material for the second charge transport layer was prepared as follows.

As a dispersant
Fluorine atom-containing resin (trade name: GF-300, manufactured by Toagosei Co., Ltd.) 0.5 part is replaced with 1,1,2,2,3,4,4-heptafluorocyclopentane (trade name: Zeolora H , Manufactured by Nippon Zeon Co., Ltd.) and 20 parts of 1-propanol. To this, 10 parts of tetrafluoroethylene resin powder (trade name: Lubron L-2, manufactured by Daikin Industries, Ltd.) was added as a lubricant. Then, this was subjected to four treatments at a pressure of 600 kgf / cm ² with a high-pressure disperser (trade name: Microfluidizer M-110EH, manufactured by Microfluidics, USA) and dispersed uniformly. Further, this was filtered with a polyflon filter (trade name: PF-040, manufactured by Advantech Toyo Co., Ltd.) to prepare a lubricant dispersion. Thereafter, 90 parts of a hole transporting compound represented by the following formula (4),

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

  Using this paint, a second charge transport layer was applied on the charge transport layer and then dried in an oven at an atmospheric temperature of 50 ° C. for 10 minutes. Thereafter, irradiation with an electron beam was performed for 1.6 seconds in nitrogen while rotating the cylinder at 200 rpm under conditions of an acceleration voltage of 150 kV and a beam current of 3.0 mA. Subsequently, the temperature was raised from 25 ° C. to 125 ° C. over 30 seconds in nitrogen to carry out a curing reaction. In addition, when the absorbed dose of the electron beam at this time was measured, it was 15 kGy. The oxygen concentration in the electron beam irradiation and heat curing reaction atmosphere was 15 ppm or less. Then, this is naturally cooled to a temperature of 25 ° C. in the atmosphere, and after-heat treatment is performed in the atmosphere for 30 minutes in an oven at a temperature of 100 ° C., a protective layer (second charge transport layer) having a thickness of 5 μm is formed. An electrophotographic photosensitive member was obtained.

  The obtained electrophotographic photosensitive member was subjected to the same procedure as in Example 1 except that the height Z of the mold used in Example 1 was changed to a hexagonal column shape of 4.00 μm and the processing pressure was 5.0 MPa. Thus, an electrophotographic photosensitive member was produced. Thereafter, evaluation was performed in the same manner as in Example 9. The results are shown in Table 1.

(Example 24)
Similar to Example 1, the layers up to the charge generation layer were formed. Subsequently, what added 25 parts of (methylsulfinyl) methane in the coating material for charge transport layers in Example 1 was prepared, and the charge transport layer was formed as follows. First, the coating solution temperature was cooled to 15 ° C., dip-coated on the charge generation layer, and the cooled coating solution for the charge transport layer was applied on the support. The step of applying the charge transport layer coating solution was performed at a relative humidity of 45% and an ambient temperature of 25 ° C. After 10 seconds from the end of the coating process, the support on which the coating liquid for the charge transport layer has been applied is held for 60 seconds in the apparatus for the dew condensation process, in which the inside of the apparatus is in a state where the relative humidity is 50% and the ambient temperature is 28 ° C. did. 120 seconds after the completion of the dew condensation process, the support was placed in a blower dryer that had been heated to 120 ° C. in advance, and the drying process was performed for 60 minutes. In this way, a charge transport layer having a concave shape on the surface and a film thickness of 15 μm was formed.

  The obtained electrophotographic photoreceptor was evaluated in the same manner as in Example 1. The results are shown in Table 1.

(Example 25)
In the same manner as in Example 23, an electrophotographic photoreceptor having a protective layer (second charge transport layer) having a thickness of 5 μm was produced. A concave portion was formed on the outermost surface layer of the obtained electrophotographic photoreceptor using a KrF excimer laser (wavelength λ = 248 nm). At this time, as shown in FIG. 20, a quartz glass mask having a pattern in which circular laser beam transmitting portions f having a diameter of 17 μm are arranged at intervals of 1.7 μm was used. The irradiation energy of the excimer laser was 1.4 J / cm ² and the irradiation area per irradiation was 2 mm square. As shown in FIG. 12, irradiation was performed while rotating the photosensitive member and shifting the irradiation position in the axial direction. Thus, an electrophotographic photosensitive member having a concave shape on the surface was produced.

  The obtained electrophotographic photoreceptor was evaluated in the same manner as in Example 1. The results are shown in Table 1.

(Comparative Example 1)
In Example 1, evaluation was performed using an electrophotographic photosensitive member that does not form a concave shape. The results are shown in Table 2. An attempt was made to rotate the photoreceptor without toner, but the blade could not be rotated because the blade broke. In addition, an attempt was made to start durability evaluation with toner interposed, but since the blade turned up within the initial few sheets, the durability was stopped.

(Comparative Example 2)
In Example 1, an electrophotographic photosensitive member having no concave shape was evaluated under the conditions shown in Table 2. The results are shown in Table 1. An attempt was made to rotate the photoreceptor without toner, but the blade could not be rotated because the blade was swollen as in Comparative Example 1. In addition, the endurance evaluation was started with toner interposed, but the endurance was stopped because an image passing through the toner was confirmed within the initial few sheets.

(Comparative Example 3)
Evaluation was performed in the same manner as in Comparative Example 2 using the electrophotographic photosensitive member used in Example 1. The results are shown in Table 2. When the photosensitive member was rotated without toner, the blade tended to be slightly distorted, but the rotation was possible. However, an attempt was made to start the durability evaluation by interposing the toner, but the endurance was stopped because an image passing through the toner was confirmed within the initial few sheets.

(Comparative Example 4)
Using the electrophotographic photosensitive member used in Example 1, evaluation was performed under the conditions shown in Table 2. The results are shown in Table 2. An attempt was made to rotate the photoreceptor without toner, but the blade could not be rotated because the blade was swollen as in Comparative Example 1. In addition, an attempt was made to start durability evaluation with toner interposed, but since the blade turned up within the initial few sheets, the durability was stopped.

(Comparative Example 5)
In Example 1, an electrophotographic photosensitive member was produced and evaluated in the same manner as in Example 1 except that the interval Y between the molds used was changed from 0.10 μm to 0.25 μm. The results are shown in Table 2. An attempt was made to rotate the photoreceptor without toner, but the blade could not be rotated because the blade was swollen as in Comparative Example 1. Durability evaluation was attempted with toner intervened, but since the blade chattered within the initial few sheets and a slip-through image of the toner was confirmed, the durability was stopped.

(Comparative Example 6)
In Example 1, an electrophotographic photoreceptor was prepared and evaluated in the same manner as in Example 1 except that the mold interval Y used was changed from 0.10 μm to 0.45 μm. The results are shown in Table 2. An attempt was made to rotate the photoreceptor without toner, but the blade could not be rotated because the blade was swollen as in Comparative Example 1. In addition, an attempt was made to start durability evaluation with toner interposed, but since the blade turned up within the initial few sheets, the durability was stopped.

(Comparative Example 7)
In Example 1, an electrophotographic photosensitive member having no concave shape was evaluated under the conditions shown in Table 2. The results are shown in Table 2. An attempt was made to rotate the photoreceptor without toner, but the blade could not be rotated because the blade was swollen as in Comparative Example 1. Further, as a result of durability evaluation with toner interposed, it was confirmed that although the cleaning property was good, the torque was significantly increased.

(Comparative Example 8)
In Example 1, the used mold interval Y was changed from 0.10 μm to 0.25 μm, and the evaluation was performed under the conditions shown in Table 2. The results are shown in Table 2. An attempt was made to rotate the photoreceptor without toner, but the blade could not be rotated because the blade was swollen as in Comparative Example 1. Further, as a result of durability evaluation with toner interposed, it was confirmed that although the cleaning property was good, the torque was significantly increased.

It is a figure which shows the example of the contact method of the cleaning blade with respect to an electrophotographic photoreceptor. It is a figure which shows another example of the contact method of the cleaning blade with respect to an electrophotographic photoreceptor. It is a figure which shows the example of the setting angle | corner of the cleaning blade with respect to an electrophotographic photoreceptor. It is a figure which shows the example of the conventional setting angle | corner of the cleaning blade with respect to an electrophotographic photoreceptor. It is a figure which shows the contact state of the cleaning blade with respect to an electrophotographic photoreceptor. 1 is a diagram illustrating an example of an image forming apparatus and a process cartridge according to the present invention. It is a figure which shows the detail of an example of the contact method of the cleaning blade in this invention. It is a figure which shows the example of the contact method of the cleaning blade blade and cleaning blade in this invention. It is a figure which shows the example of the opening shape of the recessed part of the electrophotographic photoreceptor surface in this invention. It is a figure which shows the example of the cross-sectional shape of the recessed part of the electrophotographic photoreceptor surface in this invention. It is the elements on larger scale which show the example of the arrangement pattern of the mask used for formation of the recessed part in this invention. It is the schematic which shows the example of a structure of the laser processing apparatus in this invention. It is the elements on larger scale which show the example of the arrangement pattern of the recessed part of the electrophotographic photoreceptor surface obtained by this invention. It is the schematic which shows the example of the press-contact shape transfer processing apparatus used for the recessed part formation by the mold in this invention. It is the schematic which shows the example of the press-contact shape transfer processing apparatus used for the recessed part formation by the mold in this invention. It is a figure which shows the example of the shape of the mold used for the recessed part formation in this invention. It is a figure which shows the shape of the mold used in Example 1. FIG. 3 is a partially enlarged view showing an array pattern of recesses on the surface of an electrophotographic photosensitive member obtained in Example 1. FIG. 10 is an enlarged view showing a cleaning blade having a hardened layer used in Example 9. FIG. FIG. 26 is a partially enlarged view showing an arrangement pattern of masks used in Example 25.

Explanation of symbols

a Electrophotographic photosensitive member b Cleaning blade c Cleaning blade cut surface d Cleaning blade air surface e Laser light blocking part f Laser light transmitting part g Excimer laser light irradiator h Work rotating motor i Work moving device j Photosensitive drum k Non-recessed portion l Recessed portion t Thickness of cleaning blade θ1 Setting angle of cleaning blade with respect to photosensitive member θ2 Cleaning angle 1 Electrophotographic photosensitive member 2 Axis 3 Charging means 4 Exposure light 5 Developing means 6 Transfer means 7 Cleaning means 7a Cleaning Blade 7b Blade support sheet metal 7c Cleaning blade cut surface 7d Cured layer of cleaning blade 8 Fixing means 9 Process cartridge 10 Guide means A Contact portion between photoconductor and cleaning blade D Length of recess on photoconductor surface Diameter E Distance between recesses on the surface of the photoreceptor H Depth of the recesses on the surface of the photoreceptor L Free length of the cleaning blade P Transfer material S Smooth surface before formation of recesses on the surface of the photoreceptor X Major axis diameter of the protrusions in the mold Y Convex spacing Z Height of convex part in mold I Pressure device II Mold III Photoconductor

Claims (2)

An electrophotographic photosensitive member; developing means for developing an electrostatic latent image formed on the peripheral surface of the electrophotographic photosensitive member with toner; and toner remaining on the peripheral surface of the electrophotographic photosensitive member by an elastic blade. In an image forming apparatus having a cleaning means for cleaning,
A plurality of independent recesses are formed on the surface of the electrophotographic photosensitive member,
The average value D ′ of the opening major axis diameter of the recess is 0.50 μm or more and 1.50 μm or less, and the average depth H ′ of the recess is 2.00 μm or more and 4.00 μm or less,
The ratio H ′ / D ′ of the average depth H ′ to the average value D ′ of the aperture major axis diameter is 1.53 or more and 4.00 or less ,
The opening area ratio of the recess is 80% or more and 90% or less,
The set angle θ1 of the elastic blade with respect to the electrophotographic photosensitive member at the contact portion between the electrophotographic photosensitive member and the elastic blade is 45 ° or more and 70 ° or less,
The cleaning angle θ2 of the cut surface of the elastic blade at the contact portion with respect to the electrophotographic photosensitive member is 20 ° or more and 40 ° or less,
The contact length of the elastic blade in the contact portion in the rotational movement direction of the electrophotographic photosensitive member is 20 μm or more and 30 μm or less,
The contact pressure of the elastic blade on the electrophotographic photosensitive member at the contact portion is 0.6 MPa or more and 2.0 MPa or less,
The elastic blade is in contact with the electrophotographic photosensitive member at a linear pressure of 15 g / cm or more and 40 g / cm or less at the contact portion;
An image forming apparatus, wherein the elastic blade is a cleaning blade mainly composed of urethane rubber, and an average circularity of the toner is 0.925 or more and 0.981 or less. An electrophotographic photosensitive member; developing means for developing an electrostatic latent image formed on the peripheral surface of the electrophotographic photosensitive member with toner; and toner remaining on the peripheral surface of the electrophotographic photosensitive member by an elastic blade. In a process cartridge that integrally supports a cleaning means for cleaning and is detachable from the image forming apparatus main body,
A plurality of independent recesses are formed on the surface of the electrophotographic photosensitive member,
The average value D ′ of the opening major axis diameter of the recess is 0.50 μm or more and 1.50 μm or less, and the average depth H ′ of the recess is 2.00 μm or more and 4.00 μm or less,
The ratio H ′ / D ′ of the average depth H ′ to the average value D ′ of the aperture major axis diameter is 1.53 or more and 4.00 or less ,
The opening area ratio of the recess is 80% or more and 90% or less,
The set angle θ1 of the elastic blade with respect to the electrophotographic photosensitive member at the contact portion between the electrophotographic photosensitive member and the elastic blade is 45 ° or more and 70 ° or less,
The cleaning angle θ2 of the cut surface of the elastic blade at the contact portion with respect to the electrophotographic photosensitive member is 20 ° or more and 40 ° or less,
The contact length of the elastic blade in the contact portion in the rotational movement direction of the electrophotographic photosensitive member is 20 μm or more and 30 μm or less,
The contact pressure of the elastic blade on the electrophotographic photosensitive member at the contact portion is 0.6 MPa or more and 2.0 MPa or less,
The elastic blade is in contact with the electrophotographic photosensitive member at a linear pressure of 15 g / cm or more and 40 g / cm or less at the contact portion;
A process cartridge, wherein the elastic blade is a cleaning blade mainly composed of urethane rubber, and the average circularity of the toner is 0.925 or more and 0.981 or less.