JP2008009196A - Electrophotographic photoreceptor, method and apparatus for manufacturing the same, and electrophotographic image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture electrophotographic photoreceptors in which a uniform photosensitive film free of unevenness has been formed in a good yield. <P>SOLUTION: In a method for manufacturing such electrophotographic photoreceptors by cleaning surfaces of cylindrical substrates 23 and coating the surfaces with a coating solution of photoreceptor materials to form photosensitive films, when the surfaces of the cylindrical substrates 23 are immersion-coated with the coating solution 44, the cylindrical substrates 23 are vibrated in a state where the cylindrical substrates 23 are supported by a cylindrical substrate holding structure by applying to the cylindrical substrates 23 a vibrational frequency larger than the natural frequency of the cylindrical substrates 23 when the bottoms of the cylindrical substrates 23 are in non-contact with the solution level 24 of the coating solution 44. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electrophotographic photosensitive member, a manufacturing method thereof, a manufacturing apparatus, and an electrophotographic image forming apparatus including the electrophotographic photosensitive member.

  In recent years, higher image quality is required for printers, copiers and the like using electrophotographic technology. An electrophotographic photosensitive member (OPC) is used in these printers, copiers, etc., and as the electrophotographic photosensitive member, an undercoat layer (UCL) and a charge generation layer (UCL) are currently formed on a conductive substrate such as an aluminum tube. CGL) and a charge transport layer (CTL) are sequentially laminated. The conductive substrate used in the electrophotographic photosensitive member is produced by mirror-finishing aluminum or impact-molding plate-like aluminum. Further, the surface of the conductive substrate may be subjected to a roughening treatment such as wet honing.

  However, when aluminum is mirror-finished, impact-molded, or roughened, mist of cutting oil, dust in the air, chips, and the like adhere to the substrate surface. Therefore, it is necessary to clean the substrate surface before laminating the undercoat layer, the charge generation layer, and the charge transport layer on the conductive substrate. As such a cleaning method, there is generally known a method of cleaning a substrate by immersing the substrate in a cleaning solution to remove foreign matters such as oil, dust, and chips adhering to the substrate.

  However, it is often impossible to obtain a sufficient cleaning effect simply by dipping, and ultrasonic waves are often used as auxiliary means.

  However, when ultrasonic waves are used, for example, strong cavitation occurs in the region of about 28 to 40 kHz, and damages the substrate with a strong impact force. This damage becomes a defect called erosion in aluminum. For this reason, it is necessary to suppress an output as much as possible, and a cleaning effect will fall. In order to avoid this, high-frequency (50 kHz or higher) ultrasonic waves are often used for precision parts, etc., but in order to increase directivity, a jig holding a substrate or a plurality of substrates is immersed. Since these interfere with the transmission of ultrasonic waves, the cleaning effect is reduced. As a method for solving such a problem, Patent Document 1 adopts a method of cleaning the substrate by applying vibration to the cleaning liquid and stirring the mixture, and setting the frequency of the vibration to a range of 1 to 100 Hz. The thing characterized by performing washing | cleaning is proposed.

  The electrophotographic photoreceptor can be produced by forming a photosensitive layer on a cylindrical substrate. In order to form a photosensitive layer on a cylindrical substrate, a dip coating method in which the cylindrical substrate is immersed in a photosensitive layer forming coating solution and the cylindrical substrate is pulled up relative to the coating solution is widely employed. This dip coating method has an advantage that a constant film thickness can be efficiently formed on a cylindrical substrate, but it is an important issue to prevent uneven coating on the surface of the cylindrical substrate.

  The uneven coating on the surface of the cylindrical substrate occurs due to various causes. For example, when a cylindrical substrate is applied, foaming may occur due to the expansion of gas in the substrate, resulting in uneven coating, or bubbles contained in the coating liquid may be included in the coating film and uneven coating may occur. Among them, the “stage unevenness” generated by vibration of the cylindrical substrate and the liquid surface during coating is a big problem in the image quality of electrophotographic equipment, and therefore, a new means that can further reduce the unevenness of the coating film generated by vibration is desired. ing.

  Patent Document 2 reports that Dd> 30 mm, where D is the inner diameter of the coating tank and d is the outer diameter of the cylindrical substrate. By using this method, the occurrence of “step unevenness” can be suppressed. However, if the width of Dd is increased, the coating device becomes enormous and the facility cost increases and the amount of coating liquid increases. When the liquid has a lifetime, there is a problem that the liquid usage rate is reduced.

  In Patent Document 3, when a cylindrical substrate is immersed in a coating solution, a free space length L ′ between a lower end surface of a gripping member inserted into the cylindrical substrate and a coating solution liquid surface inside the substrate is described. It has been reported that the ratio with the length L of the cylindrical substrate satisfies 0.05 ≦ L ′ / L ≦ 0.6. By using this method, the occurrence of “step unevenness” can be suppressed, but it is necessary to change the gripping member every time the length of the cylindrical base body changes, so that there is one for the base material length. There was a problem that the gripping member could not be used.

  Further, in Patent Document 4, the vibration of the coating liquid when pulling up the cylindrical substrate and the vibration applied to the immersion tank resonate when the cause of the “step unevenness” occurs, and the liquid level vibration of the coating liquid increases. If we find that coating unevenness occurs and control the pulling speed of the cylindrical substrate or the vibration applied to the immersion tank so as to avoid this resonance, the vibration of the liquid level of the coating liquid contained in the immersion tank is further reduced, It has been reported that uneven coating can be prevented. However, it is difficult to stably control the vibration of the liquid level of the coating liquid. For example, it may vary depending on the tension of the return pipe from the coating tank to the reservoir tank, the amount of coating liquid in the reservoir tank, clogging of the filter, etc. It has been known. Therefore, since there are many factors that contribute to vibration, the control may be complicated.

JP-A-8-305056 JP-A-4-235562 JP-A-4-235563 JP 2001-162216 A

  The low-frequency vibration (1 to 100 Hz) as described above does not have a strong directivity like an ultrasonic wave and propagates while spreading over a wide angle. Therefore, the vibration easily spreads from the vibration source to the entire cleaning liquid, and the cleaning liquid is sufficient. Therefore, it can be washed more uniformly than ultrasonic waves.

  However, in the method of Patent Document 1 in which the low-frequency vibration is applied to the cleaning liquid, when dip coating of a plurality of cylindrical substrates is performed at a high density, each substrate obstructs or interferes with the flow of the cleaning liquid. Since no vibration is transmitted to the cleaning liquid present on the inner substrate, a sufficient effect cannot be obtained, and cleaning becomes insufficient.

  If cleaning is insufficient, foreign matters such as oil, dust, and chips remain on the surface of the cylindrical substrate, and repelling, spots, etc. when applying the coating solution for forming the photosensitive layer on the surface of the cylindrical substrate. Cause coating defects. This coating defect causes black spots, white spots, and halftone image irregularities in the image when the electrophotographic photosensitive member is mounted on the image forming apparatus to form an image, which adversely affects the image quality. It will be.

  Further, as described above, it has been difficult to suppress unevenness due to vibration of the liquid surface of the coating liquid.

The object of the present invention is that even if a plurality of substrates are immersed at a high density, the contact effect of the cleaning liquid can be sufficiently obtained with respect to the cylindrical substrate, and cleaning can be performed uniformly between the cylindrical substrates. An object of the present invention is to provide a method and a method for producing an electrophotographic photosensitive member capable of stably reducing unevenness in step caused by vibration of the liquid surface of the coating liquid.

  An electrophotographic photosensitive member manufacturing method and manufacturing apparatus, an electrophotographic photosensitive member, and an image forming apparatus including the same according to the present invention have the following characteristics.

  (1) A method of manufacturing an electrophotographic photosensitive member in which a surface of a cylindrical substrate is washed and then a photosensitive material coating solution is applied to form a photosensitive coating film. A method for producing an electrophotographic photosensitive member for producing a photographic photosensitive member.

  (2) The method for producing an electrophotographic photosensitive member according to (1), wherein vibration is applied to the cylindrical substrate when the surface of the cylindrical substrate is washed.

  (3) In the method for producing an electrophotographic photosensitive member according to (1) above, an electrophotographic photosensitive member that adds vibration to the cylindrical substrate when the coating solution is dip coated on the surface of the cylindrical substrate. Production method.

  (4) In the method of manufacturing an electrophotographic photosensitive member according to (2), the vibration frequency applied to the cylindrical substrate is such that the cylindrical substrate is held in a state where the cylindrical substrate is held by a cylindrical substrate holding device. A method for producing an electrophotographic photosensitive member having a natural frequency of the cylindrical substrate when not in contact with a cleaning liquid or a vibration frequency in the vicinity of the natural frequency.

  By adding the natural frequency of the cylindrical substrate or a frequency near the natural frequency to the cylindrical substrate, the contact effect between the cylindrical substrate and the cleaning liquid is high, and when the cylindrical substrate is pulled up from the cleaning liquid, the cylindrical shape The substrate resonates, and the cleaning performance of the cleaning liquid is improved. As a result, the cleaning performance and the liquid cutting performance are improved, so that the production efficiency is improved.

  (5) In the method for producing an electrophotographic photosensitive member according to (3), the vibration frequency applied to the cylindrical substrate is such that the cylindrical substrate is held by the cylindrical substrate while the cylindrical substrate is held by a cylindrical substrate holding device. A method for producing an electrophotographic photosensitive member having a vibration frequency higher than a natural frequency of the cylindrical substrate when not in contact with a coating solution.

  By applying a vibration frequency higher than the natural frequency of the cylindrical substrate to the cylindrical substrate, a constant vibration is continuously generated while at least a part of the cylindrical substrate is immersed in the coating liquid. Since it is applied to a nearby coating solution, unevenness due to discontinuous vibration of the liquid surface of the coating solution can be suppressed.

  (6) An apparatus for producing an electrophotographic photosensitive member that forms a photosensitive coating film by applying a coating solution of a photosensitive material after cleaning the surface of a cylindrical substrate, and holding the cylindrical substrate An electrophotographic photosensitive member manufacturing apparatus comprising: an apparatus; and a vibration source that applies vibration to the cylindrical substrate through the cylindrical substrate holding device.

  (7) An electrophotographic photosensitive member manufactured using the method for manufacturing an electrophotographic photosensitive member according to (1) to (5) above.

  (8) An electrophotographic image forming apparatus comprising the electrophotographic photosensitive member according to (7).

  According to the present invention, an electrophotographic photosensitive member having a uniform photosensitive coating film without unevenness can be produced with good yield, and the produced electrophotographic photosensitive member has almost no sensitivity unevenness. An image forming apparatus provided with a photographic photosensitive member can provide a high-quality transfer image.

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

  The method for producing an electrophotographic photoreceptor of the present invention is a method for producing an electrophotographic photoreceptor in which the surface of a cylindrical substrate is washed and then a photosensitive material coating solution is applied to form a photosensitive coating film. The electrophotographic photosensitive member is manufactured by applying vibration to the substrate.

  Here, the “cylindrical substrate” includes a substrate on which the surface is not applied, and a substrate on which the undercoat layer, the charge generation layer, and the charge transport layer are applied in a single layer or multiple layers, and the drying process has not been completed yet, The “electrophotographic photosensitive member” is one in which each layer is formed on the surface through the above process.

  More specifically, the electrophotographic photoreceptor manufacturing method according to the embodiment of the present invention applies vibration to the cylindrical substrate when cleaning the surface of the cylindrical substrate. In the manufacturing method of the electrophotographic photosensitive member in the embodiment, vibration is applied to the cylindrical substrate when the coating solution is dip-coated on the surface of the cylindrical substrate.

  In particular, when vibration is applied to the cylindrical substrate when cleaning the surface of the cylindrical substrate, the vibration frequency applied to the cylindrical substrate is such that the cylindrical substrate is held in a state where the cylindrical substrate is held by a cylindrical substrate holding device. It is desirable that the natural frequency of the cylindrical substrate when the substrate is not in contact with the cleaning liquid or a vibration frequency near the natural frequency.

  As shown in FIG. 1, the cleaning liquid is sent to the liquid tank 10 provided with the mesh 12 at the bottom through the filter 18 using the pump 17. On the other hand, the cleaning liquid overflowed from the liquid tank 10 is again supplied to the pump 17 and the filter 18. Then, the liquid is again sent to the liquid tank 10. The cylindrical base body is held by a cylindrical base body holding device 101 having an expanding body 102 at its tip. That is, as will be described later, when the expansion body 102 abuts on the inner surface of the cylindrical base body, the cylindrical base body holding device 101 suspends and holds the cylindrical base body. The cylindrical base body is subjected to a cleaning process by lowering the cylindrical base body held in a suspended state to the liquid tank 10 and immersing and cleaning the cylindrical base body in the cleaning liquid and then raising the cylindrical base body.

Here, as shown in FIGS. 1 and 2, the vibration frequency of the cylindrical base body at the position where the cylindrical base body is suspended is different. That is, the frequency F ₁ of the cylindrical base 23 a when located at a distance L ₁ above the liquid level 14 and the cylindrical shape at a position where a part of the lower end of the cylindrical base is immersed for a distance L ₂ from the liquid level 14. the frequency F ₂ of the substrate 23b, the frequency F ₃ of the cylindrical body 23c in nearly all were immersed distance L ₃ minutes from immersion liquid level 14 position of the cylindrical body is by the buffer degree of cleaning fluid, vibration frequency as shown in FIG. _2, it has a _{F 1> F 2> F 3} .

When washing the cylindrical substrate, frequency F ₁ of the cylindrical substrate 23a in the case of position from the liquid surface 14 at a distance L ₁ minute _upward, i.e., the natural frequency of the cylindrical body or said intrinsic frequencies near the It is preferable to apply a vibration frequency to the cylindrical substrate. As a result, the contact effect between the cylindrical substrate and the cleaning liquid is high, and when the cylindrical substrate is pulled up from the cleaning liquid, the cylindrical substrate resonates, and the cleaning performance of the cleaning liquid is improved.

  On the other hand, when applying vibration to the cylindrical substrate when applying the coating liquid to the cylindrical substrate, the vibration frequency applied to the cylindrical substrate is the same as when the cylindrical substrate is held by the cylindrical substrate holding device. It is desirable that the vibration frequency be higher than the natural frequency of the cylindrical substrate when the lower end of the cylindrical substrate is not in contact with the coating solution.

As described above with reference to FIGS. 1 and 2, the vibration frequency of the cylindrical substrate at the position where the cylindrical substrate is suspended is different. When the coating liquid is applied to the surface of the cylindrical substrate, a vibration frequency F ₀ greater than the vibration frequency F ₁ of the cylindrical substrate 23 a when positioned a distance L ₁ above the liquid surface 14 is added to the cylindrical substrate. It is preferable. As a result, while at least a part of the cylindrical substrate is immersed in the coating solution, constant vibration is continuously applied to the cylindrical substrate and the coating solution in the vicinity of the substrate. Step unevenness due to various vibrations can be suppressed.

  In the following, a method for producing an electrophotographic photosensitive member and a cylindrical substrate cleaning, coating solution coating, and drying step will be described.

[Method for producing electrophotographic photosensitive member]
The outline of the method for producing an electrophotographic photosensitive member in the present invention will be described below. Since a cylindrical electrophotographic photosensitive member is often used, a cylindrical substrate will be described below.

  Although the material of the cylindrical substrate will be described later, an aluminum cylindrical substrate is usually used when an electrophotographic photosensitive member is manufactured. This cylindrical base is usually mirror-cut as will be described later. Mirror cutting is generally performed as follows. First, a diamond cutting tool is set on a lathe for precision cutting, and a cylindrical base that has been roughly cut in advance is fixed to a rotating flange of the lathe. Then, the cylindrical base is rotated by a lathe, and a cutting tool is applied while spraying kerosene as a lubricating oil to perform mirror cutting. Accordingly, when mirror cutting is performed on the cylindrical base body, oil from kerosene or aluminum chips may adhere to the surface of the cylindrical base body. Therefore, this cylindrical substrate is washed with a cleaning liquid (referred to as degreasing cleaning) and then rinsed. At this time, the degreasing and cleaning step (degreasing and rinsing) is effective when the cleaning method according to the present invention is used.

  The cylindrical substrate thus cleaned may be further subjected to a surface roughening process (non-mirror surface processing, unevenness forming process) (a surface roughening process). Thereby, in the electrophotographic photosensitive member, when exposure is performed, light is scattered on the surface of the cylindrical substrate 23, and generation of interference fringes is sufficiently prevented.

  When roughening the surface of a cylindrical substrate, cleaning with a rubbing member such as a brush after roughening treatment or cleaning to remove foreign substances such as abrasives attached during roughening by washing with high-pressure water, etc. May be performed (peeling step).

  Next, the above-described cleaning according to the present invention is performed. The cleaning process of the present invention is called a precision cleaning process. By using cleaning using a cleaning liquid (called precision cleaning) and rinsing cleaning, it is possible to quickly remove foreign matters missed in the peeling process (precision cleaning). Process).

  In addition, when the electrical conductivity of the pure water in the rinse cleaning tank exceeds 1 μS / cm, there is a tendency that coating film defects due to adhesion of water stains, iron rust, and the like occur. In addition, it is effective that the water temperature is 20 to 60 ° C. in terms of detergency and prevention of corrosion of the substrate.

The cylindrical substrate cleaned in this way is put into a dryer to remove moisture adhering to the substrate and dried with hot air. Thereby, the generation of spots on the substrate due to water droplets remaining on the surface of the cylindrical substrate 23 is prevented, and the occurrence of image quality defects can be sufficiently prevented in the image forming apparatus using the obtained electrophotographic photosensitive member. In addition, it wash | cleans so that the surface oil adhesion amount per 1 cm < ² > may become 1 * 10 <^-3> g or less in the outer peripheral surface of the cylindrical base | substrate 23. FIG. In this case, even if a coating solution for forming a photosensitive layer is applied to the outer peripheral surface, it is possible to sufficiently prevent the occurrence of coating defects such as repellency and spots.

  The dried cylindrical substrate is cooled to room temperature, thus completing the cleaning of the cylindrical substrate.

  In addition, it is preferable to immerse and lift the cylindrical substrate in warm pure water after the precision cleaning step of the present invention and before drying the cylindrical substrate with hot air. In this case, water droplets are unlikely to remain on the surface of the substrate, and water spots are unlikely to occur. The temperature of warm pure water is usually 40 to 70 ° C, preferably 45 to 60 ° C.

  Next, a coating solution for forming an undercoat layer is applied to the surface of the cylindrical substrate and dried. Thereby, an undercoat layer is obtained. At this time, on the surface of the cylindrical base body, the adhesion rate of foreign matters or the like that cause coating defects such as repellency and spots is sufficiently reduced. Accordingly, it is possible to sufficiently prevent the occurrence of coating defects such as repellency and stains when applying the coating liquid for forming the undercoat layer.

  Thereafter, a charge generation layer forming coating solution is applied onto the undercoat layer and dried, whereby a charge generation layer is obtained. Finally, a charge transport layer forming coating solution is applied onto the charge generation layer and dried, whereby a charge transport layer is obtained.

  There are various coating methods such as a dip coating method, a spray coating method, and a flow coat coating method as the coating method of the coating solution, and the coating method can be arbitrarily selected according to the characteristics of the coating solution. In addition, it is usually necessary to dry the coating solution every time one layer is applied, but depending on the type of the coating solution, there are some that do not require drying, so it is not always necessary to use a dryer. Further, the undercoat layer, the charge generation layer, and the charge transport layer are all photosensitive layers in this specification.

  Thus, a photosensitive layer is formed on the cylindrical substrate, and the production of the electrophotographic photosensitive member is completed. In this electrophotographic photosensitive member, the occurrence of coating defects is sufficiently prevented as described above. For this reason, even if an electrophotographic photosensitive member is mounted on an image forming apparatus to form an image, black spots, white spots, halftone image unevenness, etc. are prevented in the image, and the adverse effect on image quality is sufficiently prevented. Can be prevented.

  In the embodiment of the method for producing the electrophotographic photoreceptor, an undercoat layer is used, but the undercoat layer is not always necessary. Further, the stacking positions of the charge generation layer and the charge transport layer may be reversed. That is, a charge generation layer may be formed on the charge transport layer. Further, a protective layer may be provided in order to prevent wear of the charge transport layer. In addition, when the undercoat layer has an interference preventing function, the roughening step is not necessary. Therefore, if it is possible to complete the cleaning in the degreasing step using the method of the present invention, the degreasing step is performed. A precision cleaning process is not necessary with only the process. If it cannot be completed, a precision cleaning step may be provided after the degreasing cleaning step.

Hereinafter, the above-described undercoat layer, charge generation layer, and charge transport layer will be described in detail. The undercoat layer described above needs to have an appropriate resistance for obtaining leak resistance, and it is preferable to use metal oxide fine particles as fine particles. As the metal oxide fine particles, powder resistance of about 10 ² to 10 ¹¹ Ω · cm is required, and among them, metal oxide fine particles such as tin oxide, titanium oxide, and zinc oxide having the above resistance values are preferably used. If the resistance value of the metal oxide fine particles is lower than the lower limit of the above range, sufficient leakage resistance cannot be obtained. If the resistance value is higher than the upper limit of the range, there is a concern that the residual potential is increased.

It is also possible to perform surface treatment on the metal oxide fine particles. In the surface treatment, the surface area of the metal oxide fine particles greatly affects the electrophotographic characteristics after the surface treatment. As the metal oxide fine particles, those having a specific surface area of 10 m ² / g or more are used. Those having a specific surface area value of 10 m ² / g or less are liable to cause a decrease in chargeability and are difficult to obtain good electrophotographic characteristics.

  Moreover, 2 or more types of metal oxide fine particles can be mixed and used.

  The binder resin of the coating solution for forming the undercoat layer is acetal resin such as polyvinyl butyral, polyvinyl alcohol resin, casein, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride. Resin, polyvinyl acetate resin, vinyl chloride-vinyl acetate-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenolic resin, phenol-formaldehyde resin, melamine resin, urethane resin and other known polymer resin compounds, and charge transport A charge transporting resin having a functional group, a conductive resin such as polyaniline, and the like can be used. Among them, resins insoluble in the upper layer coating solvent are preferably used, and phenol resins, phenol-formaldehyde resins, melamine resins, urethane resins, epoxy resins, and the like are particularly preferably used.

  The ratio between the metal oxide fine particles and the binder resin in the coating solution for forming the undercoat layer can be arbitrarily set within a range where desired electrophotographic photoreceptor characteristics can be obtained.

  Various additives can be used in the coating solution for forming the undercoat layer in order to improve electrical characteristics, environmental stability, and image quality. Additives include quinone compounds such as chloranil, bromoanil and anthraquinone, tetracyanoquinodimethane compounds, fluorenones such as 2,4,7-trinitrofluorenone and 2,4,5,7-tetranitro-9-fluorenone Compounds, 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole and 2,5-bis (4-naphthyl) -1,3,4-oxadi Azoles, oxadiazole compounds such as 2,5-bis (4-diethylaminophenyl) -1,3,4-oxadiazole, xanthone compounds, thiophene compounds, 3,3 ′, 5,5′-tetra- Electron transport materials such as diphenoquinone compounds such as t-butyldiphenoquinone, electron transport pigments such as polycyclic condensation systems and azo systems, zirconium chelate compounds Titanium chelate compounds, aluminum chelate compounds, titanium alkoxide compounds, organic titanium compounds, there can be used a known material such as a silane coupling agent. Although the silane coupling agent is used for the surface treatment of the metal oxide, it can also be used as an additive added to the coating solution. Specific examples of the silane coupling agent used here include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ- Glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (Aminoethyl) -γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, and the like. Examples of zirconium chelate compounds include zirconium butoxide, zirconium zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl acetoacetate butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octoate, naphthene. Zirconate, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide and the like.

  Examples of titanium chelate compounds include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt , Titanium lactate, titanium lactate ethyl ester, titanium triethanolamate, polyhydroxy titanium stearate and the like.

  Examples of the aluminum chelate compound include aluminum isopropylate, monobutoxy aluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate) and the like.

  These compounds can be used alone or as a mixture or polycondensate of a plurality of compounds.

  As a solvent for adjusting the coating solution for forming the undercoat layer, any known organic solvent such as alcohol, aromatic, halogenated hydrocarbon, ketone, ketone alcohol, ether, ester, etc. Can be selected. For example, methanol, ethanol, n-propanol, iso-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, Usual organic solvents such as methylene chloride, chloroform, chlorobenzene, and toluene can be used.

  Moreover, the solvent used for these dispersion | distribution can be used individually or in mixture of 2 or more types. When mixing, any solvent can be used as long as it can dissolve the binder resin as the mixed solvent.

  As a method for dispersing the fine particles, methods such as a roll mill, a ball mill, a vibrating ball mill, an attritor, a sand mill, a colloid mill, and a paint shaker can be used. Further, as the coating method used when the undercoat layer 2 is provided, conventional methods such as blade coating method, wire bar coating method, spray coating method, dip coating method, bead coating method, air knife coating method, curtain coating method, etc. Can be used.

  The undercoat layer is formed on the conductive substrate using the coating solution for forming the undercoat layer thus obtained. The undercoat layer preferably has a Vickers strength of 35 or more. Furthermore, the thickness of the undercoat layer is preferably 10 μm or more, more preferably 20 μm or more and 50 μm or less.

  Further, the surface roughness of the undercoat layer is adjusted to ¼n (n is the refractive index of the upper layer) to ½λ of the exposure laser wavelength λ used in order to prevent moire images. Resin particles can be added to the undercoat layer 2 to adjust the surface roughness. As the resin particles, silicone resin particles, cross-linked PMMA resin particles, and the like can be used.

  In addition, the undercoat layer can be polished to adjust the surface roughness. As a polishing method, buffing, sand blasting, wet honing, grinding, or the like can be used.

  Further, an intermediate layer may be provided between the undercoat layer and the photosensitive layer in order to improve electrical characteristics, improve image quality, improve image quality maintenance, improve adhesion of the photosensitive layer, and the like. The intermediate layer is acetal resin such as polyvinyl butyral, polyvinyl alcohol resin, casein, polyamide resin, cellulose resin, gelatin, polyurethane resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinyl acetate resin, vinyl chloride-acetic acid In addition to polymer resin compounds such as vinyl-maleic anhydride resin, silicone resin, silicone-alkyd resin, phenol-formaldehyde resin, melamine resin, organometallic compounds containing zirconium, titanium, aluminum, manganese, silicon atoms, etc. There is.

  These compounds can be used alone or as a mixture or polycondensate of a plurality of compounds. Among them, an organometallic compound containing zirconium or silicon is excellent in performance such as a low residual potential, a small potential change due to the environment, and a small potential change due to repeated use.

  Examples of silicone compounds include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxy. Silane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl) -γ -Aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, and the like. Among these, silicon compounds particularly preferably used are vinyltriethoxysilane, vinyltris (2-methoxyethoxysilane), 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- (3,4). -Epoxycyclohexyl) ethyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N Silane coupling agents such as -phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-chloropropyltrimethoxysilane are raised.

  Examples of organic zirconium compounds include zirconium butoxide, zirconium zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl acetoacetate butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octoate, naphthene. Zirconate, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide and the like.

  Examples of organic titanium compounds include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt , Titanium lactate, titanium lactate ethyl ester, titanium triethanolamate, polyhydroxy titanium stearate and the like.

  Examples of the organoaluminum compound include aluminum isopropylate, monobutoxyaluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate) and the like.

  In addition to improving the coatability of the upper layer, the intermediate layer also serves as an electrical blocking layer, but if the film thickness is too large, the electrical barrier becomes too strong, causing desensitization and potential increase due to repetition. . Therefore, when the intermediate layer is formed, the film thickness is set in the range of 0.05 to 3 μm.

  The charge generation layer of the photosensitive layer is formed by forming a charge generation material by vacuum vapor deposition or by dispersing and applying it together with an organic solvent and a binder resin.

  When the charge generation layer is formed by dispersion coating, the charge generation layer is formed by dispersing the charge generation material together with an organic solvent, a binder resin, an additive, and the like, and applying the obtained dispersion.

  In the present invention, any known charge generating material can be used as the charge generating material. For infrared light, phthalocyanine pigments, squarylium, bisazo, trisazo, perylene, dithioketopyrrolopyrrole, for visible light, condensed polycyclic pigments, bisazo, perylene, trigonal selenium, dye-sensitized metal oxide fine particles, etc. are used. Among these, a particularly excellent performance is obtained, and a phthalocyanine pigment is used as a charge generating material that is preferably used. By using this, it is possible to obtain an electrophotographic photosensitive member having particularly high sensitivity and excellent repetitive stability. In addition, phthalocyanine pigments generally have several crystal forms, and any of these crystal forms can be used as long as it is a crystal form capable of obtaining a sensitivity suitable for the purpose. Particularly preferably used charge generating substances include chlorogallium phthalocyanine, dichlorosus phthalocyanine, hydroxygallium phthalocyanine, metal-free phthalocyanine, oxytitanyl phthalocyanine, chloroindium phthalocyanine and the like.

  The phthalocyanine pigment crystal used in the present invention is obtained by mechanically dry-pulverizing a phthalocyanine pigment produced by a known method with an automatic mortar, planetary mill, vibration mill, CF mill, roller mill, sand mill, kneader, or the like. Then, it can manufacture by performing a wet grinding process using a ball mill, a mortar, a sand mill, a kneader, etc. with a solvent. Solvents used in the above treatment are aromatics (toluene, chlorobenzene, etc.), amides (dimethylformamide, N-methylpyrrolidone, etc.), aliphatic alcohols (methanol, ethanol, butanol, etc.), aliphatic polyvalents. Alcohols (ethylene glycol, glycerin, polyethylene glycol, etc.), aromatic alcohols (benzyl alcohol, phenethyl alcohol, etc.), esters (acetic ester, butyl acetate, etc.), ketones (acetone, methyl ethyl ketone, etc.), dimethyl sulfoxide, ether (Diethyl ether, tetrahydrofuran, etc.), several mixed systems, and mixed systems of water and these organic solvents. The solvent used is used in an amount of 1 to 200 parts, preferably 10 to 100 parts, based on the pigment crystals. The treatment temperature is −20 ° C. to the boiling point of the solvent, preferably −10 to 60 ° C. In addition, grinding aids such as sodium chloride and sodium nitrate can be used during grinding. The grinding aid may be used 0.5 to 20 times, preferably 1 to 10 times the pigment. Further, phthalocyanine pigment crystals produced by a known method can be controlled by combining acid pasting or acid pasting with dry grinding or wet grinding as described above. As an acid used for acid pasting, sulfuric acid is preferable, and a sulfuric acid having a concentration of 70 to 100%, preferably 95 to 100% is used, and a dissolution temperature is -20 to 100 ° C, preferably -10 to 60 ° C. Is set. The amount of concentrated sulfuric acid is set in the range of 1 to 100 times, preferably 3 to 50 times the weight of the phthalocyanine pigment crystals. As a solvent to be precipitated, water or a mixed solvent of water and an organic solvent is used in an arbitrary amount. The temperature for precipitation is not particularly limited, but it is preferably cooled with ice or the like in order to prevent heat generation.

  The binder resin used for the charge generation layer can be selected from a wide range of insulating resins. It can also be selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinylanthracene, polyvinylpyrene, and polysilane. Preferred binder resins include polyvinyl acetal resin, polyarylate resin (polycondensate of bisphenol A and phthalic acid, etc.), polycarbonate resin, polyester resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyamide resin, acrylic resin Insulating resin such as polyacrylamide resin, polyvinyl pyridine resin, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol resin, polyvinyl pyrrolidone resin can be used, but is not limited thereto. These binder resins can be used alone or in admixture of two or more. Of these, polyvinyl acetal resin is particularly preferably used.

  In addition, the blending ratio (weight ratio) between the charge generation material and the binder resin is preferably in the range of 10: 1 to 1:10. The solvent for adjusting the coating solution can be arbitrarily selected from known organic solvents such as alcohols, aromatics, halogenated hydrocarbons, ketones, ketone alcohols, ethers, esters, and the like. . For example, methanol, ethanol, n-propanol, iso-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, Usual organic solvents such as methylene chloride, chloroform, chlorobenzene, and toluene can be used.

  Moreover, the solvent used for these dispersion | distribution can be used individually or in mixture of 2 or more types. When mixing, any solvent can be used as long as it can dissolve the binder resin as the mixed solvent.

  As a dispersion method, methods such as a roll mill, a ball mill, a vibration ball mill, an attritor, a sand mill, a colloid mill, and a paint shaker can be used. Furthermore, as a coating method used when providing this charge generation layer, a normal method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, or a curtain coating method is used. Can be used.

  Further, at the time of dispersion, it is effective for high sensitivity and high stability that the particles have a particle size of 0.5 μm or less, preferably 0.3 μm or less, more preferably 0.15 μm or less.

  Further, the charge generating material can be subjected to a surface treatment for improving the stability of electrical characteristics and preventing image quality defects. A coupling agent or the like can be used as the surface treatment agent, but is not limited thereto. Examples of coupling agents used for the surface treatment include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycol. Sidoxypropyltrimethoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- ( Examples include silane coupling agents such as aminoethyl) -γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, and γ-chloropropyltrimethoxysilane. Among these, silane coupling agents that are particularly preferably used are vinyltriethoxysilane, vinyltris (2-methoxyethoxysilane), 3-methacryloxypropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 2- ( 3,4-epoxycyclohexyl) ethyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropyltrimethoxysilane, N-2- (aminoethyl) 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxy Examples of the silane coupling agent include silane, N-phenyl-3-aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, and 3-chloropropyltrimethoxysilane.

  Zirconium butoxide, zirconium zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl acetoacetate zirconium butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octoate, zirconium naphthenate, lauric acid Organic zirconium compounds such as zirconium, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide can also be used. Tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt, titanium lactate, titanium lactate Organic titanium compounds such as ethyl ester, titanium triethanolamate, polyhydroxy titanium stearate, aluminum isopropylate, monobutoxy aluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate) An organoaluminum compound such as can also be used.

  Furthermore, various additives can be added to the coating solution for charge generation layer in order to improve electrical characteristics and image quality. Additives include quinone compounds such as chloranil, bromoanil and anthraquinone, tetracyanoquinodimethane compounds, fluorenones such as 2,4,7-trinitrofluorenone and 2,4,5,7-tetranitro-9-fluorenone Compounds, 2- (4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole and 2,5-bis (4-naphthyl) -1,3,4-oxadi Azoles, oxadiazole compounds such as 2,5-bis (4-diethylaminophenyl) -1,3,4-oxadiazole, xanthone compounds, thiophene compounds, 3,3 ′, 5,5′-tetra- Electron transport materials such as diphenoquinone compounds such as t-butyldiphenoquinone, electron transport pigments such as polycyclic condensation systems and azo systems, zirconium chelate compounds Titanium chelate compounds, aluminum chelate compounds, titanium alkoxide compounds, organic titanium compounds, there can be used a known material such as a silane coupling agent. Examples of silane coupling agents include vinyltrimethoxysilane, γ-methacryloxypropyl-tris (β-methoxyethoxy) silane, β- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltri Methoxysilane, vinyltriacetoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropyltrimethoxysilane, N-β- (aminoethyl)- γ-aminopropylmethylmethoxysilane, N, N-bis (β-hydroxyethyl) -γ-aminopropyltriethoxysilane, γ-chloropropyltrimethoxysilane, and the like. Examples of zirconium chelate compounds include zirconium butoxide, zirconium zirconium acetoacetate, zirconium triethanolamine, acetylacetonate zirconium butoxide, ethyl acetoacetate butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octoate, naphthene. Zirconate, zirconium laurate, zirconium stearate, zirconium isostearate, methacrylate zirconium butoxide, stearate zirconium butoxide, isostearate zirconium butoxide and the like.

  Examples of titanium chelate compounds include tetraisopropyl titanate, tetranormal butyl titanate, butyl titanate dimer, tetra (2-ethylhexyl) titanate, titanium acetylacetonate, polytitanium acetylacetonate, titanium octylene glycolate, titanium lactate ammonium salt , Titanium lactate, titanium lactate ethyl ester, titanium triethanolamate, polyhydroxy titanium stearate and the like.

  Examples of the aluminum chelate compound include aluminum isopropylate, monobutoxy aluminum diisopropylate, aluminum butyrate, diethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate) and the like.

  These compounds can be used alone or as a mixture or polycondensate of a plurality of compounds.

  Furthermore, as a coating method used when providing this charge generation layer, a normal method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, or a curtain coating method is used. Can be used.

  As the charge transport material contained in the charge transport layer, any known material can be used, but the following can be exemplified. Oxadiazole derivatives such as 2,5-bis (p-diethylaminophenyl) -1,3,4-oxadiazole, 1,3,5-triphenyl-pyrazoline, 1- [pyridyl- (2)]-3 Pyrazoline derivatives such as-(p-diethylaminostyryl) -5- (p-diethylaminostyryl) pyrazoline, triphenylamine, tri (p-methyl) phenylamine, N, N'-bis (3,4-dimethylphenyl) biphenyl Aromatic tertiary amino compounds such as -4-amine, dibenzylaniline, 9,9-dimethyl-N, N′-di (p-tolyl) fluoren-2-amine, N, N′-diphenyl-N, Aromatic tertiary diamino compounds such as N′-bis (3-methylphenyl)-[1,1-biphenyl] -4,4′-diamine, 3- (4′-dimethyl) 1,2,4-triazine derivatives such as minophenyl) -5,6-di- (4′-methoxyphenyl) -1,2,4-triazine, 4-diethylaminobenzaldehyde-1,1-diphenylhydrazone, 4-diphenyl Hydrazone derivatives such as aminobenzaldehyde-1,1-diphenylhydrazone, [p- (diethylamino) phenyl] (1-naphthyl) phenylhydrazone, quinazoline derivatives such as 2-phenyl-4-styryl-quinazoline, 6-hydroxy-2, Benzofuran derivatives such as 3-di (p-methoxyphenyl) -benzofuran, α-stilbene derivatives such as p- (2,2-diphenylvinyl) -N, N′-diphenylaniline, enamine derivatives, N-ethylcarbazole, etc. Carbazole derivatives, poly-N-vinylcal Hole transport materials such as vazole and its derivatives. Quinone compounds such as chloranil, bromoanil, anthraquinone, tetracyanoquinodimethane compounds, fluorenone compounds such as 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2- ( 4-biphenyl) -5- (4-t-butylphenyl) -1,3,4-oxadiazole, 2,5-bis (4-naphthyl) -1,3,4-oxadiazole, 2,5 -Oxadiazole compounds such as bis (4-diethylaminophenyl) -1,3,4-oxadiazole, xanthone compounds, thiophene compounds, 3,3 ', 5,5'-tetra-t-butyldiphenoxy Electron transport materials such as non-diphenoquinone compounds. Or the polymer etc. which have the group which consists of a compound shown above in the principal chain or a side chain are mention | raise | lifted. These charge transport materials can be used alone or in combination of two or more.

  Any known binder resin for the charge transport layer can be used, but an electric insulating film-forming resin is preferred. For example, polycarbonate resin, polyester resin, methacrylic resin, acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polystyrene resin, polyvinyl acetate resin, styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, vinyl chloride-acetic acid Vinyl copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone resin. Silicon-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, poly-N-carbazole, polyvinyl butyral, polyvinyl formal, polysulfone, casein, gelatin, polyvinyl alcohol, ethyl cellulose, phenol resin, polyamide, carboxy-methyl cellulose, vinylidene chloride Examples thereof include, but are not limited to, polymer wax and polyurethane. These binder resins are used singly or in combination of two or more. In particular, polycarbonate resins, polyester resins, methacrylic resins, and acrylic resins are compatible with charge transport materials, soluble in solvents, and strong. Excellent and preferably used. The blending ratio (weight ratio) between the binder resin and the charge transport material can be arbitrarily set in any case, but attention must be paid to a decrease in electrical characteristics and a decrease in film strength. The thickness of the charge transport layer is 5 to 50 μm, preferably 10 to 40 μm. Furthermore, as a coating method used when providing this charge transport layer, a usual method such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, or a curtain coating method is used. Can be used. As a solvent used for coating, usual organic solvents such as dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene and toluene can be used alone or in admixture of two or more.

  Further, the electrophotographic photosensitive member of the present invention includes an antioxidant and a light stabilizer in the photosensitive layer for the purpose of preventing deterioration of the photosensitive member due to ozone, oxidizing gas, or light / heat generated in the electrophotographic apparatus. Additives such as can be added.

  Examples of the antioxidant include hindered phenol, hindered amine, paraphenylenediamine, arylalkane, hydroquinone, spirochroman, spiroidanone and their derivatives, organic sulfur compounds, and organic phosphorus compounds.

  Specific examples of antioxidants include phenolic antioxidants such as 2,6-di-t-butyl-4-methylphenol, styrenated phenol, n-octadecyl-3- (3 ′, 5′-di). -T-butyl 4'-hydroxyphenyl) -propionate, 2,2'-methylene-bis- (4-methyl-6-t-butylphenol), 2-t-butyl-6- (3'-t-butyl) -5'-methyl-2'-hydroxybenzyl) -4-methylphenyl acrylate, 4,4'-butylidene-bis- (3-methyl-6-tert-butyl-phenol), 4,4'-thio-bis -(3-methyl-6-tert-butylphenol), 1,3,5-tris (4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, tetrakis- [methylene- -(3 ', 5'-di-t-butyl-4'-hydroxy-phenyl) propionate] -methane, 3,9-bis [2- [3- (3-t-butyl-4-hydroxy-5- Methylphenyl) propionyloxy] -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane. Among hindered amine compounds, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1- [2- [3 -(3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] -2, 2,6,6, -tetramethylpiperidine, 8-benzyl-7,7,9,9-tetramethyl-3-octyl-1,3,8-triazaspiro [4,5] undecane-2,4-dione, 4-benzoyloxy-2,2,6,6-tetramethylpiperidine, dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine succinate Condensate, poly [{6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diimyl} {(2,2,6,6-tetramethyl- 4-piperidyl) imino} hexamethylene {(2,3,6,6-tetramethyl-4-piperidyl) imino}], 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2- n-Butylmalonate bis (1,2,2,6,6-pentamethyl-4-piperidyl), N, N′-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl-N— (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate and the like. Dilauryl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, pentaerythritol-tetrakis- ( β-lauryl-thiopropionate), ditridecyl-3,3′-thiodipropionate, 2-mercaptobenzimidazole and the like. Examples of organophosphorus antioxidants include trisnonylphenyl phosfete, triphenyl phosfeft, and tris (2,4-di-t-butylphenyl) -phosfte.

  Organic sulfur-based and organic phosphorus-based antioxidants are referred to as secondary antioxidants, and a synergistic effect can be obtained by using them together with primary antioxidants such as phenols or amines.

  Examples of the light stabilizer include benzophenone, benzotriazole, dithiocarbamate, and tetramethylpiperidine derivatives.

  Examples of the benzophenone light stabilizer include 2-hydroxy-4-methoxy benzophenone, 2-hydroxy-4-octoxy benzophenone, and 2,2'-di-hydroxy-4-methoxy benzophenone. As a benzotriazole-based light stabilizer, 2-(-2′-hydroxy-5′-methylphenyl-)-benzotriazole, 2- [2′-hydroxy-3 ′-(3 ″, 4 ″, 5 ′) ', 6' '-tetra-hydrophthalimido-methyl) -5'-methylphenyl] -benzotriazole, 2-(-2'-hydroxy-3'-t-butyl 5'-methylphenyl-)-5-chloro Benzotriazole, 2- (2′-hydroxy-3′-t-butyl 5′-methylphenyl-)-5-chlorobenzotriazole, 2- (2′-hydroxy-3 ′, 5′-t-butylphenyl- ) -Benzotriazole, 2- (2′-hydroxy-5′-t-octylphenyl) -benzotriazole, 2- (2′-hydroxy-3 ′, 5′-di-t-amylphenyl-)-benzo Riazor and the like. Other compounds include 2,4-di-t-butylphenyl 3 ', 5'-di-t-butyl-4'-hydroxybenzoate, nickel dibutyl-dithiocarbamate and the like.

Further, at least one kind of electron accepting substance can be included for the purpose of improving sensitivity, reducing residual potential, reducing fatigue during repeated use, and the like. Examples of the electron accepting substance that can be used in the photoreceptor of the present invention include succinic anhydride, maleic anhydride, dibromomaleic anhydride, phthalic anhydride, tetrabromophthalic anhydride, tetracyanoethylene, tetracyanoquinodimethane, o -Dinitrobenzene, m-dinitrobenzene, chloranil, dinitroanthraquinone, trinitrofluorenone, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, phthalic acid and the like can be mentioned. Of these, fluorenone-based, quinone-based, and benzene derivatives having electron-withdrawing substituents such as Cl, CN, NO ₂ are particularly preferable. The charge transport layer can also contain fine particles such as silica and PTFE.

  A small amount of silicone oil can also be added to the coating solution as a leveling agent for improving the smoothness of the coating film.

  In the electrophotographic photoreceptor of the present invention, a protective layer can be provided on the photosensitive layer as necessary. In the electrophotographic photosensitive member having a laminated structure, this protective layer is used to prevent chemical change of the charge transport layer during charging or to further improve the mechanical strength of the photosensitive layer. The protective layer includes a curable resin, a siloxane resin cured film containing a charge transporting compound, a film formed by containing a conductive material in a suitable binder resin, and the like. Any curable resin can be used as long as it is a public resin. Examples thereof include phenol resin, polyurethane resin, melamine resin, diallyl phthalate resin, and siloxane resin. In the case of a cured siloxane resin film containing a charge transporting compound, any known material can be used as the charge transporting compound. For example, JP-A-10-95787, JP-A-10-251277, Examples thereof include, but are not limited to, compounds disclosed in JP-A-11-32716, JP-A-11-38656, and JP-A-11-236391. When the protective film is a film formed by containing a conductive material in a suitable binder resin, examples of the conductive material include metallocene compounds such as N, N′-dimethylferrocene, N, N′-diphenyl- Aromatic amine compounds such as N, N′-bis (3-methylphenyl)-[1,1′-biphenyl] -4,4′-diamine, molybdenum oxide, tungsten oxide, antimony oxide, tin oxide, titanium oxide, Indium oxide, tin oxide and antimony or antimony oxide solid solution carrier, or a mixture thereof, or a mixture of these metal oxide fine particles in a single particle, or a coated one, but is not limited thereto. It is not something.

  The binder resin used for this protective layer is polyamide resin, polyvinyl acetal resin, polyurethane resin, polyester resin, epoxy resin, polyketone resin, polycarbonate resin, polyvinyl ketone resin, polystyrene resin, polyacrylamide resin, polyimide resin, polyamideimide resin. Known resins such as these can be used, and these can be used after being crosslinked. The protective layer can contain an antioxidant. Specific examples of antioxidants include phenolic antioxidants such as 2,6-di-t-butyl-4-methylphenol, styrenated phenol, n-octadecyl-3- (3 ′, 5′-di). -T-butyl 4'-hydroxyphenyl) -propionate, 2,2'-methylene-bis- (4-methyl-6-t-butylphenol), 2-t-butyl-6- (3'-t-butyl) -5'-methyl-2'-hydroxybenzyl) -4-methylphenyl acrylate, 4,4'-butylidene-bis- (3-methyl-6-tert-butyl-phenol), 4,4'-thio-bis -(3-methyl-6-tert-butylphenol), 1,3,5-tris (4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate, tetrakis- [methylene- -(3 ', 5'-di-t-butyl-4'-hydroxy-phenyl) propionate] -methane, 3,9-bis [2- [3- (3-t-butyl-4-hydroxy-5- Methylphenyl) propionyloxy] -1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane. Among hindered amine compounds, bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate, 1- [2- [3 -(3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] ethyl] -4- [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy] -2, 2,6,6-tetramethylpiperidine, 8-benzyl-7,7,9,9-tetramethyl-3-octyl-1,3,8-triazaspiro [4,5] undecane-2,4-dione, 4, -Benzoyloxy-2,2,6,6-tetramethylpiperidine, dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine heavy succinate Compound, poly [{6- (1,1,3,3-tetramethylbutyl) imino-1,3,5-triazine-2,4-diimyl} {(2,2,6,6-tetramethyl- 4-piperidyl) mino} hexamethylene {(2,3,6,6-tetramethyl-4-piperidyl) mino}], 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2- n-Butylmalonate bis (1,2,2,6,6-pentamethyl-4-piperidyl), N, N′-bis (3-aminopropyl) ethylenediamine-2,4-bis [N-butyl-N— (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate and the like. Dilauryl-3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, pentaerythritol-tetrakis- ( β-lauryl-thiopropionate), ditridecyl-3,3′-thiodipropionate, 2-mercaptobenzimidazole and the like. In addition to known antioxidants such as trisnonylphenyl phosfetes, triphenyl phosfetes, tris (2,4-di-t-butylphenyl) -phosfetes as organophosphorus antioxidants, they can be combined with siloxane resins. Examples thereof include an antioxidant having a functional group such as a hydroxyl group, an amino group, and an alkoxysilyl group.

  Furthermore, the protective layer may contain fine particles such as silica and PTFE. The thickness of the protective layer is 1 to 20 μm, preferably 1 to 10 μm. Further, as a coating method used when the protective layer 5 is provided, usual methods such as a blade coating method, a wire bar coating method, a spray coating method, a dip coating method, a bead coating method, an air knife coating method, and a curtain coating method are used. Can be used. As a solvent used for coating, ordinary organic solvents such as dioxane, tetrahydrofuran, methylene chloride, chloroform, chlorobenzene, and toluene can be used singly or as a mixture of two or more kinds, but a solvent in which the lower layer is hardly dissolved is used as much as possible. It is preferable.

The electrophotographic photosensitive member obtained by the present invention can be used in electrophotographic apparatuses such as laser beam printers, digital copying machines, LED printers, and laser facsimiles that emit near-infrared light or visible light. The laser beam is preferably a laser that oscillates light of 350 to 800 nm in order to obtain a high-definition image. Further, the laser beam preferably has a spot diameter of 10 ⁴ μm ² or less, more preferably 3 × 10 ³ μm ² or less in order to obtain a high-definition image.

  In the electrophotographic photoreceptor obtained by the present invention, the functional layer above the charge generation layer for obtaining high resolution has a thickness of 60 μm or less, preferably 40 μm or less. When the functional layer is a thin film, the combination of the particle-dispersed undercoat layer of the present invention and a high-strength protective layer is particularly effectively used.

  The electrophotographic photosensitive member can be used in combination with a one-component or two-component regular developer or reversal developer. The toner particle diameter for obtaining a high-definition image is preferably 10 μm or less, more preferably 8 μm or less. Although these toners can be close to known production methods, spherical toners obtained by a solution suspension method or a polymerization method are particularly preferably used. Further, a surface lubricant (metal fatty acid salt) and fine particles having an abrasive effect can be added to the toner.

  In addition, the electrophotographic photosensitive member manufactured by using the manufacturing method of the present invention can obtain good characteristics with little occurrence of current leakage even in a contact charging method using a charging roller, a charging film, and a charging brush.

  Next, cleaning of the cylindrical substrate will be described below with reference to the drawings.

[Cylindrical substrate cleaning]
(Cleaning device)
FIG. 3 shows the configuration of the first embodiment of the cylindrical substrate cleaning apparatus. As shown in FIG. 3, the cleaning device includes a cleaning tank 20 that stores the cleaning liquid 40, and the upper part of the cleaning tank 20 is open. The bottom of the cleaning tank 20 may be flat, but the corners may be cut to reduce accumulation. In the case of immersing a plurality of cylindrical substrates 23, the cleaning tank 20 needs to be proportionally larger. Therefore, in FIG. 3, only one supply port 28 is provided. It is desirable to arrange them at equal intervals if possible. In order to increase efficiency in the cleaning tank 20, the ultrasonic device 29 may be provided as an auxiliary means. The output and frequency of the ultrasonic wave are appropriately determined. When ultrasonic waves are installed, since it is necessary to prevent the ultrasonic waves from blocking the supply port 28, the ultrasonic waves may be attached to the lower side and the side surface of the cleaning tank 20.

  An overflow liquid receiving tank 21 is provided on the upper side surface of the cleaning tank 20, and the cleaning liquid once received in the overflow liquid receiving tank 21 is returned to the reservoir tank 26 via the overflow pipe 25. The reservoir tank 26 stores a cleaning liquid 40 in advance, and the reservoir tank 26 is connected to a supply port 28 provided at the bottom of the cleaning tank 20 by a supply pipe 22 via a pump 17 and a filter 18.

  In the cleaning apparatus shown in FIG. 3, the cleaning liquid overflowed from the cleaning tank 20 is returned from the overflow liquid receiving tank 21 to the reservoir tank 26 through the overflow pipe 25, further fed by the pump 17, and foreign matter is removed by the filter 18. After that, a circulation system for supplying the cleaning tank 20 again is adopted. According to the circulation system, water can be reused and it is economical. The filter 18 may be appropriately determined with respect to the required cleaning performance. However, when high-quality cleaning is required like an electrophotographic photosensitive member, an opening of 0.01 to 40 μm is preferable. More preferably, it has a mesh size of 0.2 to 10 μm. Two filters may be provided, and a coarse filter having a pre-filter on the upstream side of the flow may be provided. Further, the reservoir tank 26 may be provided in the middle.

  On the other hand, the cylindrical base 23 is placed on a pallet 30 provided with a gripper that can be held in contact with the inner wall surface of the lower part of the cylindrical base, and is immersed by the lifting device 27 via the pallet 30. After being cleaned, it is pulled up from the cleaning tank 20. The cylindrical substrate 23 may be gripped from the upper part or the lower part (FIG. 3 is a lower grip). Further, when gripping the cylindrical base body, it is better not to block the entire inner surface of the cylindrical base body. Then, since a flow through which the cleaning liquid passes through the inner surface of the cylindrical substrate is formed, foreign substances existing on the inner surface of the cylindrical substrate can move smoothly. The pallet 30 is provided with a connecting rod 31, and the connecting rod 31 is connected to the lifting device 27. The elevating device 27 is provided with a motor 33 that drives the pallet 30 to be movable up and down via the connecting rod 31. The lifting device 27 has a specification capable of swinging the cylindrical base 23 up and down a plurality of times. That is, using the motor 33 as a vibration source, the pallet 30 is swung or vibrated up and down as will be described later. Further, it is more preferable to vibrate the cleaning liquid 40 using an ultrasonic device 29 disposed in the cleaning tank 20. As a result, the foreign matter adhering to the surface of the cylindrical substrate 23 can be efficiently removed from the cylindrical substrate.

(Cylindrical substrate cleaning method)
Next, a method for cleaning the cylindrical substrate 23 using the above-described cleaning apparatus will be described. For example, taking an electrophotographic photosensitive member as an example, any material may be used as the material of the cylindrical substrate 23 as long as it is conventionally used. For example, metals such as aluminum, nickel, chromium, stainless steel, and plastic films provided with thin films such as aluminum, titanium, nickel, chromium, stainless steel, gold, vanadium, tin oxide, indium oxide, ITO, etc. Examples thereof include paper coated with or impregnated with a property-imparting agent, and a plastic film. The shape of the substrate 1 may be a sheet shape or a plate shape, but a cylindrical shape is often used.

  The cylindrical base is usually subjected to pretreatment such as etching, anodizing, rough cutting, centerless grinding, and the like. The substrate is usually mirror-cut. Further, the substrate is subjected to a surface-roughening process for making it non-mirror surface for the purpose of preventing interference fringes or imparting irregularities of a desired shape. At this time, oil, dust, or metal chips may adhere to the surface of the cylindrical substrate.

Next, such a cylindrical substrate 23 is washed. The cleaning tank 20, the supply pipe 22, and the reservoir tank 26 are filled with the cleaning liquid 40 and are circulated by the pump 17. The cleaning liquid 40 that has passed through the pump 17 passes through the filter 18 through the supply pipe 22, is sent from the supply port 28 into the cleaning tank 20, and then circulates through the reservoir tank 26 after the overflow and through the pump 17 again. Is done. Although it is desirable that the supply amount per unit time supplied from the pump 17 (circulation flow rate in the case of circulation) is large, a large supply amount results in an increase in size of the pump 17 and incidental equipment, resulting in high costs. Therefore, when the supply amount of the cleaning liquid 40 is Q, the time from the time when the cylindrical substrate 23 is immersed in the cleaning tank 20 to the time when the next cylindrical substrate 23 is immersed is T, and the volume of the cleaning tank 20 is V. And Q, T, and V are the following formulas:
0.5 ≦ QT / V
If it is preferable to consider the cost,
10.0 ≧ QT / V
Is more preferable. When QT / V is less than 0.5, foreign substances accumulate in the cleaning tank, and the foreign substances tend to reattach to the substrate 1.

  Then, the lifting / lowering device 27 is driven through the pallet 30 provided with the gripping tool, and the cylindrical base 23 is lowered and immersed in the cleaning liquid 40 of the cleaning tank 20 (immersion process). The substrate is stopped for a certain period of time at the lowermost position, washed with vibrations, and then the cylindrical substrate 23 is raised (lifting step).

  During the pulling process, it is desirable to apply vibrations of 1 Hz to 5000 Hz to the cylindrical substrate 23. If it is less than 1 Hz, the cleaning power is poor, and if it exceeds 5000 Hz, the motor 33 that is a general-purpose vibration device cannot cope with it, and the cost increases. Moreover, it is preferable that the amplitude of the vibration to provide exists in 0.1-20 mm. If the amplitude is too small, the cleaning power is poor, and if the amplitude is too large, the motor 33, which is a general-purpose vibration device, cannot cope with the cost. Further, since a high load is applied to the lifting device 27, it is considered that the failure frequency increases.

  More preferably, during the pulling process, the natural frequency of the cylindrical substrate 23 when the cylindrical substrate 23 is not in contact with the cleaning liquid 40 with the cylindrical substrate 23 held by the pallet 30 provided with the gripping tool or The pallet 30 is vibrated using a motor 33 of the lifting device 27 at a vibration frequency near the natural frequency. In general, the natural frequency of a cylindrical substrate used in an electrophotographic photosensitive member that is most frequently used is, for example, about 35 Hz, and the pallet 30 can be vibrated at a vibration frequency of 35 Hz or its vicinity by using a motor 33. desirable. Thereby, the cylindrical base body 23 causes a resonance phenomenon, and the liquid cutting property is improved.

  Moreover, although the said motor 33 may use a commercially available vibration apparatus, the method of transmitting rotation of a motor etc. is simple. Since the pump 17 normally selects a rotation speed of 3 to 60 Hz, the pump 17 may be brought into contact with the lifting device 27. The vibration may be performed only during the period during which the liquid is pulled up, or may be further vibrated for a while after stopping until it comes out of the liquid surface and reaches the stop position. If the substrate is vibrated even at a position above the liquid level, the cleaning liquid adhering to the base can be dropped into the cleaning tank, and the adhering liquid can be reused. The use efficiency of the liquid is increased and the cost is excellent.

  The dipping / pulling process may be repeated, and the stopping position at the time of pulling may be in the liquid or above the liquid level. By this operation, foreign matters such as oil, dust and chips adhering to the cylindrical base 23 are removed by the cleaning liquid, and the cylindrical base 23 is cleaned.

  The cleaning liquid 40 is not particularly limited as long as it is a liquid capable of cleaning the cylindrical substrate, but an aqueous cleaning liquid is used from the viewpoint of protecting the global environment and ease of handling. For example, (1) water such as city water, pure water, ion exchange water, well water, (2) nonionic series such as polyoxyethylene alkylphenyl ether, polyoxyethylene / polyoxypropylene / block copolymer type and nonylphenol polyoxyethylene ether Surfactant, alkylbenzene, higher alcohol, anionic surfactant such as oxyacid salt such as sulfuric acid, silicic acid, phosphoric acid and carbonic acid of α-olefin, (3) electrolytic alkaline ionized water, Reducing water (manufactured by JEOL Active Co., Ltd., trade names: EKO-13, EKO-13AL, etc.), (4) Known cleaning liquids such as any mixture of (1) to (3). However, in view of the cleaning effect, (3) electrolytic alkaline ionized water or a kind of super-reducing water (manufactured by JEOL Active Ltd., trade names: EKO-13, EKO-13AL, etc.) is expensive. Is preferred.

  Next, a second embodiment of the cleaning apparatus will be described below with reference to FIG. In addition, the same code | symbol is attached | subjected to the same structure as FIG. 3, and the description is abbreviate | omitted.

  In the cleaning apparatus of FIG. 4, the cylindrical base body 23 is suspended and held by the cylindrical base body holding apparatus 101 having the expansion body 102, and is immersed and cleaned in the cleaning tank 20. Moreover, as shown in FIG. 4, you may wash | clean sequentially using multiple washing | cleaning apparatuses. In that case, you may wash | clean from the front stage to the back | latter stage, ie, changing the component, density | concentration, and liquid temperature of the washing | cleaning liquid 40 in the washing tank 20 gradually. The larger the number of cleaning devices, the lower the possibility that foreign matters such as oil, dust, and metal chips adhering to the cylindrical substrate 23 after cleaning will be attached, but the number of tanks is determined in consideration of cost. In addition, the cleaning liquid may be returned from the overflow liquid receiving tank 21 directly to the cleaning tank 20 through the filter 18 and circulated through the filter 18.

  Further, the cylindrical substrate 23 moves in the direction of the black arrow in FIG. In view of this, it is desirable that the cleaning tank 20 in the last latter stage does not return the overflowing cleaning liquid from the other cleaning tank 20 to the reservoir tank 26.

  In the case of the cleaning apparatus shown in FIG. 4, the vibration for applying vibration to the cylindrical base 23 in the immersion cleaning process and the pulling-up process is performed by the vertical movement of the cylindrical base 23 by the cylindrical base holding apparatus 101. 6 and 7, the vibration source 120a may be disposed on the substrate 188 on which the upper end portion of the cylindrical substrate holding device 101 is fixed, or the upper portion of the cylindrical substrate holding device 101 may be provided. The vibration sources 120b and 120c may be provided inside the fixed portion 102a or the fixed portion 102a where the expansion body 102 is located, respectively.

  Normally, after the cleaning with the cleaning liquid, rinsing is performed for the purpose of removing the cleaning liquid from the substrate. Similarly, with respect to the rinsing, a rinsing tank is used instead of the cleaning tank 20 shown in FIGS. 3 and 4, and this rinsing tank is filled with pure water instead of the cleaning liquid 40, and the cylindrical substrate 23 after cleaning is filled therein. After immersing and holding for a predetermined time, it is lifted from the tank and rinsed. Pure water is supplied from the bottom of the rinsing tank, overflowed from the upper open end of the rinsing tank, circulated and reused. As for the rinsing, if necessary, a plurality of rinsing tanks may be provided in multiple stages, and the rinsing treatment may be performed by sequentially immersing them.

  Next, application of the coating solution for forming the photosensitive layer on the cylindrical substrate will be described with reference to the drawings.

[Coating to cylindrical substrate]
(Coating device and coating method)
FIG. 5 shows an example of the configuration of an apparatus for applying a photosensitive layer forming coating solution onto a cylindrical substrate.

  FIG. 5 shows a state where the cylindrical substrate 23 is being pulled up from the coating solution tank 50. The coating liquid 44 is pumped from the reservoir tank 26 through the supply pipe 22 by the pump 17 and is supplied into the coating liquid tank 50 through the filter 18. In the coating liquid tank 50, at least one or more meshes 52 are inserted in the lower part in order to obtain a uniform coating liquid flow rate in the tank. The coating liquid 44 supplied into the coating liquid tank 50 has independent coating chambers 54 that can be immersed in each cylindrical substrate 23. The coating liquid 44 supplied into the independent coating chamber 54 overflows, is collected in the overflow liquid receiving tank 21 provided around the upper end of the coating liquid tank 50, flows out into the overflow pipe 25, and is collected in the reservoir tank 26. The

  When dip coating is performed using this dip coating apparatus, the cylindrical substrate 23 is always overflowed for the purpose of holding the coating liquid bath liquid surface 24 constant when immersed in an independent coating chamber 54 and then pulled up. Thus, the coating liquid is circulated by the coating liquid circulation means. Furthermore, a discharge port 51 for discharging the solvent vapor is provided in the middle of the overflow pipe 25, but the discharge port 51 is preferably provided at a position lower than the liquid level 24 of the coating liquid tank 50. By forcibly sucking solvent vapor from the discharge port 51, film thickness unevenness is suppressed. The discharge port supplies air from A and discharges from B, so that the C suction chamber is decompressed and solvent vapor is forcibly discharged, that is, the air ejector effect is used for discharge. As a means, there is no problem even if an electric or pneumatic vacuum pump is used. It is preferable to provide a pressure gauge 38 for indicating the degree of vacuum of C. The solvent vapor discharged using the air ejector effect passes through the pipe 45 and is discharged to the reservoir tank 26. At that time, the solvent is cooled by the solvent vapor cooler 49, the saturated vapor pressure of the organic solvent vapor is lowered, and the organic solvent is condensed. The solvent vapor cooler 49 is preferably provided with a thermometer 41 for measuring the cooling temperature. The agglomerated organic solvent travels through the pipe 45 and mixes with the coating liquid 44 in the reservoir tank 26 by gravity. As a means for cooling the solvent vapor, the method of bringing the cooling water 42 into contact with the pipe 45 is described here, but the present invention is not limited to this.

  Further, a hood 35 for preventing the influence of an external air flow is provided on the upper part of the coating solution tank 50. Here, when the discharge port 51 is not provided, or when the discharge port 51 is set at a location higher than the liquid level 24 of the coating liquid tank 50, the solvent vapor evaporated from the coating film formed on the cylindrical substrate 23, and The solvent vapor evaporating from the liquid surface 14 of the coating liquid tank 50 is also affected by the provision of the hood 35 so as not to be affected by the external air flow, and stays around the cylindrical substrate. In the thick film coating, the amount of evaporated solvent vapor from the coating film further increases, so that the solvent vapor is insufficiently discharged in the natural discharge, and the touch film drying rate unevenness of the coating film formed on the cylindrical substrate 23 is generated. However, in the present invention, by providing a means for forcibly sucking the solvent vapor to the discharge port 51, that is, the solvent vapor in the dry region around the cylindrical substrate is uniformly and thickly applied. Even if the amount of solvent vapor increases, it is possible to obtain an electrophotographic photoreceptor excellent in the effect of discharging and having little film thickness unevenness.

  The cylindrical substrate is usually applied with the end not immersed in the liquid sealed. Various methods of gripping the cylindrical substrate have been reported, but a contact portion formed with a flat contact surface that contacts the end of the cylindrical substrate with a small misalignment when gripping the substrate. And a biasing mechanism that biases the support portion of the expansion body that grips the cylindrical base body in the contact surface direction and presses the end of the cylindrical base body against the contact surface. Is preferred.

  Hereinafter, examples of the gripping structure and the vibration configuration of the cylindrical substrate holding device 101 will be described with reference to FIGS.

  As shown in FIG. 6, each of the cylindrical substrate holding devices 101 includes a fixed portion 101a and a movable portion 101b. Among these, the expansion body 102 is provided in the lower end part of the movable part 101b. As shown in FIG. 3, the fixed portion 101a is fixed to the substrate 188, and the movable portion 101b is configured to be movable up and down with respect to the fixed portion 101a. As shown in FIG. 6A, the movable portion 101b is biased upward by an elastic member (for example, a spring) 198 provided between the movable portion 101b and the fixed portion 101a. Further, as shown in FIG. 7, the movable portion 101 b is pressed downward from the upper pneumatic cylinder 90. The pressing force by the pneumatic cylinder 90 is set larger than the urging force by the elastic member 198. When the pneumatic cylinder 90 generates the pressing force, the movable portion 101b moves downward as shown in FIG. 6B. . In the present embodiment, in the state of FIG. 6B, that is, in a state where the movable portion 101 b is pressed downward by the pneumatic cylinder 90, pressurized air is supplied through the tube 106 and the through hole 108 to expand the expansion body 102. Then, the cylindrical base 23 is gripped, and then the state shown in FIG. 6A, that is, the pressing by the pneumatic cylinder 90 is released, and the movable portion 101 b is returned upward by the urging force of the elastic member 198. Thereby, the upper end 23u of the cylindrical base | substrate 23 is pressed on the contact surface 101c provided in the fixing | fixed part 101a. The gripping by the expandable body 102 alone may cause the cylindrical base 23 to be distorted and sway or swing or move up and down. However, by pressing the upper end 23u of the cylindrical base 23 against the contact surface 101c, the cylindrical base 23 may be The base substrate 23 can be firmly held in a fixed posture, and the axial deviation can be substantially suppressed to 1 mm or less, depending on the length of the substrate. Here, the contact surface 101c is preferably a flat surface. By doing so, even if the cylindrical base 23 has a different inner diameter, it can be firmly held in a fixed posture as long as the cross section of the upper end 23u is included in the contact surface 101c. At this time, the contact surface 101c is preferably a horizontal surface (a surface perpendicular to the axial direction of the arm 101). However, in order to press the upper end 23u of the cylindrical base 23 against the contact surface 101c by this method, the gap y between the upper end 23u and the contact surface 101c when gripping the cylindrical base 23 in FIG. It should be noted that the stroke x needs to be smaller than the stroke x in FIGS. 6 (a) and 6 (b). In this example, the fixed portion 101a corresponds to the contact portion, the movable portion 101b corresponds to the support portion of the expansion body 102, the elastic member 198 corresponds to the urging mechanism, and the pneumatic cylinder 90 corresponds to the pressing mechanism. However, this is merely an example, and the present invention is not limited to this configuration. The tube 106 and the through hole 108 are also used as a path for extracting pressurized air from the expansion body 102. In FIGS. 1 and 4, the expanded state of the expansion body 102 is indicated by broken lines.

  Normally, unevenness of the step occurs due to resonance at a position where the natural frequency of the cylindrical substrate reduced by the buoyancy of the liquid and the vibration of the pump 17 become the same.

  As shown in FIG. 7, a vibration source 120a having a variable excitation function between 10 Hz and 200 Hz is disposed on a substrate 188, and vibration is applied to the cylindrical substrate via the cylindrical substrate holding device 101. May be. In addition, as shown in FIG. 7, a vibration source 120b may also be disposed inside the fixed portion 102a above the cylindrical substrate holding device 101, or the vibration source 120c may be disposed inside the fixed portion 102a where the expansion body 102 is located. It may be arranged. As the vibration sources 120a, 120b, and 120c, for example, a motor or a piezoelectric element can be used. In addition, since the natural frequency of the cylindrical substrate used in the electrophotographic photosensitive member that is most frequently used is, for example, about 35 Hz, the vibration sources 120a, 120b, 120c have, for example, a frequency higher than 35 Hz. For example, it is desirable to generate a vibration frequency of 40 Hz or more.

  By applying vibration at a frequency larger than the natural vibration of the cylindrical substrate when not immersed in the liquid from the cylindrical substrate holding device to the cylindrical substrate, unevenness can be prevented from occurring. The upper limit value of the frequency to be applied is not particularly limited, but 500 Hz or less is preferable because it is necessary to apply vibration to all the cylindrical substrates held by the substrate 188. That is, when a frequency exceeding 500 Hz is applied, a large amount of energy is required to transmit the vibration to the lower side of the cylindrical substrate, which is inefficient. The inventors consider that unevenness due to vibration of the base material due to resonance can be reduced by positively and constantly applying vibration of a frequency that does not resonate with the vibration of the pump to the cylindrical substrate.

  Next, the drying process of the cylindrical substrate coated with the photosensitive layer coating solution will be described with reference to FIG.

[Drying of cylindrical substrate]
(Drying device)
FIG. 8A shows the configuration of a cylindrical substrate drying apparatus in the present invention, while FIG. 8B shows the configuration of a conventional cylindrical substrate drying apparatus. . In FIG. 9, time is expressed in the form of time 1 to time 5.

  When changing the product type, as shown in FIG. 8B, the drying conditions such as the drying temperature can be changed until the cylindrical substrate 23 of the previous product of the conventional cylindrical substrate drying furnace 70 is completely removed from the drying furnace 70. There wasn't. On the other hand, in the present invention, the drying furnace is composed of a plurality of chambers 61, 62, 63, 64 equipped with an air circulation device whose temperature is controlled. The drying conditions of each chamber can be changed sequentially. As shown in FIG. 8 (a), at time 1, the drying furnace contains a full cylindrical substrate 23, but at time 2, the drying furnace chamber 61 does not contain the cylindrical substrate 23. The drying conditions of the chamber 61 can be changed. In this way, the change of the product type is greatly shortened by sequentially changing the drying conditions of the chambers 62, 63, 64 of the drying furnace each time the chambers 62, 63, 64 of the drying furnace and the cylindrical base 23 are removed. be able to. That is, according to the electrophotographic photosensitive member manufacturing apparatus of the present invention, it is possible to greatly shorten the type switching time of electrophotographic photosensitive members having different drying conditions.

[Preferred embodiment]
(1) A method for cleaning a cylindrical substrate, comprising a dipping step of immersing a plurality of cylindrical substrates in a cleaning liquid, and a pulling-up step of pulling up the cylindrical substrate from the cleaning liquid. A method for cleaning a cylindrical substrate, wherein the substrate is vibrated at 1 Hz to 5000 Hz.
(2) A method for producing an electrophotographic photoreceptor, wherein vibration is applied to the cylindrical substrate at a frequency of 10 Hz to 500 Hz, preferably 10 Hz to 200 Hz, when the coating solution is dip-coated on the surface of the cylindrical substrate.
(3) The electrophotographic photosensitive member manufactured by using the method for manufacturing a photosensitive member for an electrophotographic photosensitive member according to any one of (1) or (2) or claims 1 to 5, and A charging means for charging the electrophotographic photosensitive member; an exposure means for exposing the electrophotographic photosensitive member charged by the charging means to form an electrostatic latent image; and developing the electrostatic latent image with toner. An electrophotographic apparatus comprising: a developing unit that forms a toner image; and a transfer unit that transfers the toner image to a recording medium.

  EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example and a comparative example, this invention is not limited to a following example at all.

[Cylindrical substrate cleaning]
(Example 1)
A cylindrical substrate made of an aluminum base tube (JIS H4080 alloy number: 1050A) was mirror-cut using a diamond tool to obtain a thickness of 0.75 mm, an outer diameter of 30 mm, and a length of 340 mm. Thereafter, the surface was finished into a smooth surface having a ten-point average roughness (Ra) of 0.03 to 0.04 μm.

  Cleaning was performed along the cleaning step shown in FIG.

  First, after completion of the mirror cutting, a plurality of cleaning tanks 20 shown in FIG. 3 are provided, and the cylindrical substrate is degreased and cleaned by a cleaning system that sequentially immerses and cleans the cylindrical substrate in the next cleaning tank (degreasing cleaning step). . In the above cleaning system, degreasing was first performed sequentially with the two previous cleaning apparatuses. A cleaning solution in which a surfactant is dissolved in ion-exchanged water is supplied from the bottom to the two preceding cleaning tanks 20 and overflows from the top. As the surfactant, a nonionic surfactant (LH-600F manufactured by Lion Corporation) is used, and the concentration of the surfactant in the cleaning liquid is 10 to 20% by weight in the first-stage cleaning tank 20, In the second-stage washing tank 20, the content was set to 1 to 2% by weight. Further, as the ion exchange water for the cleaning liquid, one having an electric conductivity of 1 μS / cm or less was used. Further, an ultrasonic wave of 40 kHz was applied to the cylindrical substrate 23 through an cleaning liquid with an output that does not generate erosion by an ultrasonic oscillator.

  In addition, as shown in FIG. 10, it arrange | positioned so that the distance between centers of cylindrical base | substrates might be set to 60 mm, and 16 pieces of 4 vertical x 4 horizontal were immersed simultaneously. The size of the tank was set to 45 liters of 300 mm × 300 mm and a depth of 500 mm. The circulation flow rate was 100 liters / min, and the residence time in each cleaning device was 2.5 minutes. During the immersion, the substrate was lifted 2.0 minutes after the 50 mm stroke was swung up and down in the liquid at a speed of 500 mm / min. After degreasing and cleaning the cylindrical substrate in this manner, the cylindrical substrate was rinsed and cleaned sequentially in the following two rinsing apparatuses (third and fourth cleaning tanks 20). Rinse washing was performed in the same manner as degreasing washing except that only ion-exchanged water was used as the washing liquid.

  After rinsing and washing, warm pure water immersion was performed in the last-stage washing apparatus 20. The cylindrical substrate was immersed in warm pure water maintained at 35 ° C. for 50 seconds and then pulled up at a speed of 300 mm / min.

  The surface of the cylindrical substrate thus obtained was roughened by a wet honing device (roughening step). In the roughening treatment, a suspension obtained by suspending 5.7 kg of an abrasive in 51 liters of water is sent to a gun at a flow rate of 10 liters / min, and cylindrical with a compressed air pressure of 0.1 to 0.2 MPa. It sprayed on the base | substrate, and it was made for the surface roughness 10 point average roughness (Ra) to be 0.1-0.3 micrometer. As the abrasive, aluminum oxide having a particle size of 35 μm (Aluna beads (CB-A35S) manufactured by Showa Titanium Co., Ltd.) was used.

  The following cleaning treatment was performed on the cylindrical substrate thus roughened (peeling step). That is, first, well water was sprayed on a roughened cylindrical base body at 25 liter / min for 60 seconds, and then a pressing treatment was performed with a pressing brush while 0.2% surfactant was sprayed at 2 liter / min. . As the pressing brush, one composed of a rod-shaped shaft member and a number of nylon brushes attached radially to the shaft member was used. The wire diameter of the brush is 65 μm, the outer diameter of the brush part is 130 mm, the brush length is 30 mm, the shaft member is parallel to the rotation axis of the cylindrical substrate, and the tip of the brush contacts the surface of the cylindrical substrate. Arranged to be. The pressing process was performed for 60 seconds with the rotation direction of the cylindrical substrate and the pressing brush being the same direction and the rotation speed being 100 rpm.

  As shown in FIG. 4, the cylindrical substrate thus pressed was cleaned by a cleaning system including a plurality of cleaning tanks and sequentially immersing the cylindrical substrate in the next cleaning tank (precise cleaning process). In the cleaning system, the first and second cleaning tanks 20a and 20b (the same shape as the tank in the degreasing cleaning process 300 mm × 300 mm, the depth of 500 mm in a volume of 45 liters) Water (conductivity 0.1-1.0 [mu] S / cm, temperature 18-25 [deg.] C.) is placed, and the third stage cleaning tank 20c is warm pure water (conductivity 0.1-1.0 [mu] S / cm, temperature 48-55). C). Then, in each of the two previous cleaning tanks 20a and 20b, the pump 17b is operated to suck up pure water from the reservoir tank 26, respectively, and is filtered through the filter 18b, and then supplied to the supply pipes 22a and 22b, The cleaning liquid was supplied into the cleaning tanks 20a and 0b from the respective supply ports 28a and 28b. At this time, the circulation flow rate Q was set to 100 L liter / min (same as the above degreasing cleaning step).

  In this state, the moving device 130 is moved along the guide rail 129 to the position directly above the cleaning tank 20a, and the cylindrical base 23 is disposed right above the cleaning tank 20a. The substrate was lowered and immersed in the cleaning liquid of the cleaning tank 20a. Thereafter, the cylindrical base body 23 was pulled up, the moving device 130 was moved along the guide rail 129, and was placed directly above the next cleaning tank 20b. Thereafter, the cylindrical substrate 23 was cleaned in the same manner. At this time, the residence time in each washing tank 20a, 20b was 2.5 minutes.

  3, and the cylindrical substrate holding device 101 of FIG. 4, during immersion, the cylindrical substrate 23 swings up and down in the liquid at a speed of 500 mm / min with a stroke of 50 mm. Pulled up after 0 minutes. Further, during the pulling up by each cleaning device 20, the vibrating device (Emic Co., Ltd. small vibration generator 511 -A) 13 is brought into contact with the lifting device 27 in FIG. 3 and the cylindrical substrate holding device 101 in FIG. The substrate was vibrated with an amplitude of 1 mm in the lateral direction. After the completion of the pulling, the vibration was continuously applied until it moved to the next cleaning device.

  In the final-stage cleaning tank 20c, the cylindrical substrate 23 was immersed in the cleaning liquid for 20 seconds, and then slowly lifted and cleaned at a speed of 300 mm / min.

  The cylindrical substrate 23 washed in the final-stage washing tank 20c is dried by blowing hot air at 135 ° C. for 2 minutes in the drying chamber (hot air drying step), and then cooled by air so that the temperature of the substrate becomes 25 ° C. And cooled (cooling step).

  Next, 100 parts of an organozirconium compound (trade name: Orgatics ZC540, manufactured by Matsumoto Pharmaceutical Co., Ltd.), 10 parts of a silane coupling agent (trade name: A1100, manufactured by Nihon Unicar Co., Ltd.), polyvinyl butyral resin (trade name) : BM-S, manufactured by Sekisui Chemical Co., Ltd.) and a coating solution obtained by mixing 130 parts of n-butyl alcohol. A cylindrical substrate is dip-coated and heated at 140 ° C. for 15 minutes to obtain a thickness. An undercoat layer of 1.0 μm was formed.

  Next, a hydroxygallium phthalocyanine pigment is mixed in a 2% cyclohexanone solution of polyvinyl butyral resin (trade name: BM-1, manufactured by Sekisui Chemical Co., Ltd.) so that the ratio of the pigment to the resin is 2: 1. Then, a dispersion treatment was performed for 3 hours by a sand mill. The obtained dispersion was further diluted with n-butyl acetate and dip-coated on the undercoat layer to form a charge generation layer having a thickness of 0.15 μm.

  Next, a solution in which 4 parts of N, N′-diphenyl-N, N′-bis (m-tolyl) benzidine and 6 parts of polycarbonate Z resin are dissolved in 36 parts of monochlorobenzene is dip-coated on the charge generation layer, The film was dried at 115 ° C. for 40 minutes to form a charge transport layer having a thickness of 24 μm. Thus, an electrophotographic photosensitive member was obtained.

  In addition, about another cylindrical base | substrate which performed the washing | cleaning process similarly, the surface oil component adhesion amount was computed as follows, without performing application | coating. That is, first, 550 ml of an oil component extraction solvent (trade name: S-316, manufactured by Horiba, Ltd.) was placed in an ultrasonic bath, and ultrasonic waves were applied for 5 minutes. Then, 30 ml of the extraction solvent was collected, and the oil concentration A (unit: mg / l) was measured with an oil concentration measuring device (OCMA-220, manufactured by Horiba, Ltd.). Thus, the oil concentration (background) contained in advance in the oil extract was measured.

Next, the cylindrical substrate was completely immersed in 520 ml of oil extract remaining in the ultrasonic bath, and ultrasonic waves were applied for 5 minutes. Then, 30 ml of the oil extract was collected and the oil concentration B (unit: mg / l) was measured in the same manner as described above. And the following formula:
Surface oil adhesion amount = (oil concentration B−oil concentration A) × 520 / (1000 × surface area of cylindrical substrate [cm ² ])
Based on the above, the surface oil adhesion amount was calculated. As a result, the surface oil adhesion amount was the detection limit (less than 5 × 10 ⁻⁵ mg / cm ² ).

(Example 2)
It was the same as Example 1 except that 5 Hz vibration was given at the time of pulling up.

Example 3
The same as Example 1 except that a vibration of 1000 Hz was applied at the time of pulling up.

Example 4
As in Example 1, mirror cutting was performed.

  After mirror finishing, the cylindrical substrate is degreased / precisely cleaned and rinsed in the same manner as degreased cleaning except that only ion-exchanged water is used as a cleaning solution. Was immersed in warm pure water (electric conductivity is 1 μS / cm or less) maintained at 48 to 55 ° C. for 20 seconds and then pulled up at a speed of 300 mm / min.

  The washed cylindrical substrate 23 is dried by blowing hot air at 135 ° C. for 2 minutes in the drying chamber (hot air drying step), and then cooled by applying cold air so that the temperature of the substrate becomes 25 ° C. (cooling step). .

Next, a coating film was formed on the outer peripheral surface of the cylindrical body. An undercoat layer having the following constitution was applied and cured at 150 ° C. for 30 minutes to obtain a film thickness of 20 μm.
Titanium oxide 25 parts by weight Blocked isocyanate as a resin precursor (trade name: Sumitomo Bayern Urethane Sumijoule 3175) 10 parts by weight Methyl ethyl ketone 60 parts by weight Butyral resin (trade name: Sekisui Chemical BM-1) 9 parts by weight 3 parts by weight of a silicone ball (trade name: Tospearl 120 manufactured by Toshiba Silicone) 0.01 part by weight of a leveling agent (trade name: silicone oil SH29PA manufactured by Toray Dow Corning Silicone)

  Next, a hydroxygallium phthalocyanine pigment is mixed in a 2% cyclohexanone solution of polyvinyl butyral resin (trade name: BM-1, manufactured by Sekisui Chemical Co., Ltd.) so that the ratio of the pigment to the resin is 2: 1. Then, a dispersion treatment was performed for 3 hours by a sand mill. The obtained dispersion was further diluted with n-butyl acetate and dip-coated on the undercoat layer to form a charge generation layer having a thickness of 0.15 μm.

  Next, a solution in which 4 parts of N, N′-diphenyl-N, N′-bis (m-tolyl) benzidine and 6 parts of polycarbonate Z resin are dissolved in 36 parts of monochlorobenzene is dip-coated on the charge generation layer, The film was dried at 115 ° C. for 40 minutes to form a charge transport layer having a thickness of 24 μm. Thus, an electrophotographic photosensitive member was obtained.

In addition, about another cylindrical base | substrate which performed the washing | cleaning process similarly, when the surface oil adhesion amount was measured by the method similar to Example 1 without performing application | coating, it was 5 * 10 < ^-4 > mg / cm < ² >. .

(Comparative Example 1)
Example 1 was the same as Example 1 except that no vibration was applied by the vibration exciter.

(Comparative Example 2)
It was the same as Example 1 except that a vibration of 0.5 Hz was given at the time of pulling up.

(Comparative Example 3)
The same procedure as in Example 1 was performed except that a 28 kHz ultrasonic transducer was installed at the bottom of the tank.

(Evaluation of defect rate)
About 1000 electrophotographic photoreceptors obtained in Examples 1 to 4 and Comparative Examples 1 to 3, the number of defects on the surface of the photoreceptor is measured using a surface defect evaluation apparatus composed of a CCD camera and a microscope, and defects are generated. The rate was calculated. As a result, the defect occurrence rate was as shown in Table 1.

  From this, it was found that the defect generation rate was sufficiently reduced in the example. Similarly, the surface oil adhesion amount was as shown in Table 1. Moreover, it turned out that a defect generation rate becomes so small that the amount of surface oil adhesion is small.

[Coating to cylindrical substrate]
<Example 5>
(Preparation of base material)
The aluminum pipe (cylindrical base material) is mirror-cut by a mirror lathe using a diamond tool, and the surface roughness (Ra (centerline average roughness defined in JIS B0601 (1982)): 0.02 μm, Rmax (maximum height specified in JIS B0601 (1982)): 0.2 μm) was finished. Next, the substrate was washed (electrolytic alkaline water treatment) using electrolytic alkaline water in a circulation type processing apparatus. The electrolytic alkaline water supplied / circulated to the treatment tank is 3 times the stock solution (trade name: Lumic EKO-13AL, manufactured by JEOL Active) containing 3.4 wt% of ions other than water. Diluted (pH 11) was used. As ion exchange water for diluting the stock solution of electrolyzed alkaline water, one having a specific resistance of 5 (MΩ · cm) was used. The temperature of the electrolyzed alkaline water was set to 50 ° C., and the substrate was washed for 15 seconds. In addition, the frequency of the ultrasonic wave irradiated in the treatment tank was 133 kHz. The oil contained in the used electrolyzed alkaline water was separated using an ultrafine fiber filter (trade name: U-Tech TH, manufactured by Asahi Kasei Co., Ltd.) as an oil-water separator. Next, a rinsing process was performed. In the rinsing tank in the circulation type rinsing apparatus used for the rinsing treatment, ion-exchanged water having a specific resistance of 5 (MΩ · cm) was used. The temperature of the ion exchange water was set to 50 ° C. In the rinsing process, the substrate was rinsed for 15 seconds. In addition, the frequency of the ultrasonic wave irradiated in the rinsing tank was 133 kHz. Finally, draining treatment was performed. In the draining tank in the circulating drainer used for draining, ion-exchanged water having a specific resistance of 5 (MΩ · cm) was set at a liquid temperature of 50 ° C. and used. The substrate was dipped in the draining tank 25b for 15 seconds and then pulled up at 2000 mm / min. Then, it dried with 60 degreeC hot air with a dew point of 7 degrees C or less, and obtained the cylindrical base | substrate (outer diameter 60mm, thickness 1mm, length 357mm).

(Preparation of coating solution for undercoat layer)
On the other hand, 100 parts by weight of zinc oxide (average particle size 70 nm: prototype product manufactured by Teika) is stirred and mixed with 500 parts by weight of toluene, and 1.5 parts by weight of a silane coupling agent (KBM603: manufactured by Shin-Etsu Chemical Co., Ltd.) is added. Stir for 2 hours. Thereafter, toluene was distilled off under reduced pressure, and baking was performed at 150 ° C. for 2 hours to obtain a surface-treated zinc oxide. Next, 60 parts by weight of the surface-treated zinc oxide, 15 parts by weight of a curing agent (blocked isocyanate Sumijoule 3175, manufactured by Sumitomo Bayern Urethane Co., Ltd.), and 15 weights of butyral resin (ESLEC BM-1, manufactured by Sekisui Chemical Co., Ltd.) A part was dissolved in 85 parts by weight of methyl ethyl ketone, 38 parts by weight of this solution and 25 parts by weight of methyl ethyl ketone were mixed, and dispersion treatment was performed for 2 hours with a sand mill using glass beads having a diameter of 1 mmφ. As a catalyst, 0.005 part by weight of dioctyltin dilaurate was added to the obtained dispersion to obtain a coating solution for forming an undercoat layer.

(Application of undercoat layer)
This coating solution was circulated in a dip coating circulator including a filter in which the piping in front of the dip coating tank had an inner diameter of 21 mm and the opening of the circulation filter had an absolute filtration accuracy of 25 μm. In this dip coating tank, 232 cylindrical substrates were applied at a speed of 250 mm per minute after being immersed at once. The independent coating chamber 54 has an inner diameter of 77 mm. Thereafter, the film was dried and cured at 170 ° C. for 40 minutes to obtain a coating film having an average film thickness of 24 μm.

(Preparation of coating solution for charge generation layer)
Next, a solution prepared by dissolving 4 parts of a vinyl chloride-vinyl acetate-maleic acid copolymer (VMCH, manufactured by Union Carbide) in 100 parts of acetic acid-n-butyl and 4 parts of a type II chlorogallium phthalocyanine crystal were mixed, A coating solution for forming a charge generation layer having a solid content of 7.0% by weight was prepared by dispersing with glass beads for 12 hours in a dynomill and diluting with n-butyl acetate.

(Application of charge generation layer)
This coating solution was circulated at a flow rate of 20 liters per minute in the dip coating circulator shown in FIG. In this dip coating tank, 232 cylindrical base bodies were immersed at a time and then applied at a pulling rate of 170 mm per minute. The independent coating chamber 54 has an inner diameter of 77 mm. At the time of application, a vibration of 40 Hz was applied to the substrate 188 (FIG. 7). It was 35 Hz when the natural vibration of the cylindrical substrate was measured when it was not immersed in the liquid. The degree of vacuum in the suction chamber C in FIG. 5 was controlled by the pressure gauge 38, and the amount of air flow (ejector air amount) was adjusted and determined so as to be −5 kPa. The pressure (degree of vacuum) here is a parameter that is arbitrarily set in consideration of physical properties of the coating liquid, film thickness unevenness target value, etc., but is preferably. It is desirable to set to −0.1 kPa to −20 kPa. The temperature of the cooling water in the solvent vapor cooler 49 was set to 10 ° C. The temperature of the cooling water here is a parameter that is arbitrarily set in consideration of the aggregation and regeneration amount of the solvent, but is preferably set to 20 ° C. or less. Then, it heat-dried at 100 degreeC for 10 minute (s), and formed the 0.25 micrometer-thick charge generation layer.

<Comparative Example 4>
The charge generation layer was applied in the same manner as in Example 5 except that the charge generation layer was not vibrated.

<Comparative Example 5>
The charge generation layer was coated up to the charge generation layer in the same manner as in Example 5 except that the vibration (vibration) frequency was changed to 25 Hz by coating the charge generation layer.

<Comparative Example 6>
The charge generation layer was coated up to the charge generation layer in the same manner as in Example 5 except that the vibration (vibration) frequency was changed to 20 Hz by coating the charge generation layer.

(Evaluation)
The cylindrical substrate formed up to the charge generation layer was visually evaluated under a yellow lamp to confirm whether or not a step unevenness occurred. In Example 5, no twelve irregularities were observed, but in Comparative Example 1, eight irregularities were found at a position 50 mm from the lower end of the substrate. In Comparative Examples 2 and 3, twelve irregularities were found at steps 60 mm and 100 mm from the lower end of the substrate.

  As an application example of the present invention, there is application to a photoreceptor in an image forming apparatus such as a copying machine or a printer using an electrophotographic system.

It is a figure which shows the positional relationship of a cylindrical base | substrate and a liquid level. It is a graph which shows the relationship between the distance of the cylindrical base | substrate shown in FIG. 1, and a liquid level, and the frequency of a cylindrical base | substrate. It is a schematic block diagram which shows an example of the washing | cleaning apparatus of a cylindrical base | substrate. It is a schematic block diagram which shows the other example of the washing | cleaning apparatus of a cylindrical base | substrate. It is a schematic block diagram which shows an example of the coating device of a cylindrical base | substrate. It is a schematic block diagram explaining the schematic structure of a cylindrical base | substrate holding | maintenance apparatus, and the contact state to a cylindrical base | substrate. It is a schematic block diagram explaining the example of arrangement | positioning of the vibration source in a cylindrical base | substrate holding | maintenance apparatus. It is a schematic block diagram explaining the difference between this invention and a prior art about the drying process of the cylindrical base | substrate with which the photosensitive layer was apply | coated. It is a figure explaining a washing process. It is a figure explaining the holding | maintenance space | interval of a cylindrical base | substrate at the time of using the washing | cleaning apparatus shown in FIG.

Explanation of symbols

  20, 20a, 20b, 20c Cleaning tank, 22, 22a, 22b Supply piping, 23 Cylindrical base, 24 Liquid level, 25 Overflow piping, 26 Reservoir tank, 27 Lifting device, 28, 28a, 28b Supply port, 30 Pallet, 31 Connecting rod, 33 Motor, 35 Hood, 38 Pressure gauge, 40 Cleaning liquid, 41 Thermometer, 42 Cooling water, 44 Coating liquid, 50 Coating liquid tank, 51 Discharge port, 54 Coating chamber, 90 Pneumatic cylinder, 101 Cylindrical substrate Holding device, 101a fixed part, 101b movable part, 101c contact surface, 102 expansion body, 106 tube, 108 through-hole, 120a, 120b, 120c vibration source.

Claims (8)

A method for producing an electrophotographic photoreceptor, in which a surface of a cylindrical substrate is washed and then a photosensitive material coating solution is applied to form a photosensitive coating film.
A method for producing an electrophotographic photoreceptor, comprising producing an electrophotographic photoreceptor by applying vibration to the cylindrical substrate. In the manufacturing method of the electrophotographic photosensitive member according to claim 1,
A method for producing an electrophotographic photosensitive member, wherein vibration is applied to the cylindrical substrate during cleaning of the surface of the cylindrical substrate. In the manufacturing method of the electrophotographic photosensitive member according to claim 1,
A method of manufacturing an electrophotographic photosensitive member, wherein vibration is applied to the cylindrical substrate when the coating solution is dip-coated on the surface of the cylindrical substrate. In the manufacturing method of the electrophotographic photosensitive member according to claim 2,
The vibration frequency applied to the cylindrical substrate is the natural frequency of the cylindrical substrate or the natural frequency when the cylindrical substrate is not in contact with the cleaning liquid while the cylindrical substrate is held by a cylindrical substrate holding device. A method for producing an electrophotographic photosensitive member, wherein the vibration frequency is in the vicinity of a frequency. In the manufacturing method of the electrophotographic photosensitive member according to claim 3,
The vibration frequency applied to the cylindrical substrate is larger than the natural frequency of the cylindrical substrate when the cylindrical substrate is not in contact with the coating liquid while the cylindrical substrate is held by the cylindrical substrate holding device. A method for producing an electrophotographic photosensitive member, characterized by having a vibration frequency. An apparatus for producing an electrophotographic photosensitive member that forms a photosensitive coating film by applying a coating solution of a photosensitive material after cleaning the surface of a cylindrical substrate,
A cylindrical substrate holding device for holding the cylindrical substrate;
A vibration source for applying vibration to the cylindrical substrate via the cylindrical substrate holding device;
An apparatus for producing an electrophotographic photosensitive member, comprising:   An electrophotographic photosensitive member manufactured using the method for manufacturing an electrophotographic photosensitive member according to claim 1.   An electrophotographic image forming apparatus comprising the electrophotographic photosensitive member according to claim 7.

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