JP4325330B2 - Electrophotographic photoreceptor manufacturing equipment - Google Patents

Description

  The present invention relates to an apparatus for producing an electrophotographic photosensitive member that forms a photosensitive layer on the surface of a cylindrical substrate by a dip coating method.

  An electrophotographic photoreceptor is usually produced by applying a photoreceptor material to the surface of a cylindrical substrate. In this case, a dip coating method is generally used in order to uniformly apply the photosensitive material to the surface of the cylindrical substrate. In the dip coating method, a cylindrical substrate is immersed in a coating solution, and then a wet film is formed on the surface of the substrate by pulling it up at an appropriate rate, and the wet film is dried and solidified to form a photosensitive layer. In the process of changing from a wet film to a dry film (natural drying process), slight wind near the coating film, uneven vapor pressure concentration, surface tension gradient, uneven film thickness, orange peel, repellency failure, etc. on the photosensitive layer surface. The natural drying process is controlled by devising the shape of the lid and hood (cylindrical wind shield) of the dip coating tank.

  As a means for improving the productivity of the organic photoreceptor, a method in which a plurality of cylindrical substrates are simultaneously applied by dip coating is employed. In this case, a method of immersing and applying a plurality of cylindrical base materials in one large dip tank (coating tank) or a method of dip coating in the same number of dip tanks (coating tanks) as the cylindrical base material is used. . In any case, in order to suppress evaporation of the solvent contained in the coating liquid and to control the concentration of the solvent vapor in the vicinity of the base material, a lid for covering the portion that receives the overflowed liquid, and further the natural drying process In order to precisely control the hood, the hood is provided above the coating liquid surface of the coating tank, usually using a lid as a gantry.

  It is also effective to increase the integration density of the cylindrical base material in order to reduce the cost of the above-mentioned dip coating apparatus and mass production plant. That is, by increasing the integration density, it is possible to obtain effects such as reducing the size of the coating device and shortening the time for changing the type. However, when the integration density of the cylindrical base material is increased, the distance between the base materials is reduced, which may cause a quality problem that cannot be considered when the integration density is low.

  For example, when the lower end (coating liquid side) portion of the cylindrical substrate is pulled out from the coating liquid surface, a thin film is formed between the lower end end surface of the cylindrical substrate and the coating liquid surface, or at the lower end opening of the cylindrical substrate. It is formed. The thin film is stabilized for a while in the vicinity of the coating liquid surface, and in some cases at the lower end opening, and then ruptures, and mist is scattered around. When dip coating multiple cylindrical substrates at the same time, the mist generated by the above mechanism adheres to the image area equivalent part of the wet film surface during natural drying of other adjacent cylindrical substrates, resulting in coating film defects. There was a problem to generate.

As a means for preventing the occurrence of coating film defects related to the thin film formation, for example, immediately after the cylindrical substrate is separated from the coating liquid surface, the inner surface of the cylindrical substrate is directed to the lower end opening of the cylindrical substrate. A method of applying pressure or spraying has been proposed (see, for example, Patent Documents 1 and 2). However, these methods are effective when the accumulation density of the cylindrical base material is low, but the phenomenon that the thin film ruptures occurs. Therefore, when the accumulation density is high, the improvement effect may not be obtained. .
JP 2000-189885 A JP-A-7-124519

  The present invention has been made in view of the above circumstances, and its purpose is generated by the mechanism even when a plurality of cylindrical substrates are simultaneously dip-coated in a state of high integration density. This is to prevent the mist from adhering to the image area of the wet film surface that is naturally dried on the surface of the adjacent cylindrical substrate, and to prevent the occurrence of coating film defects as a photosensitive layer.

  As a result of the study, the present inventors have determined that the interval between the lower end (coating liquid side end) of the cylindrical wind shield (hood) and the coating liquid surface is that of the photosensitive layer on the lower end side (coating liquid side) after dip coating. It has been found that the above problem can be improved by providing a hood so as to be equal to or less than the non-image area width, and the present invention has been completed.

That is, the present invention
<1> At least a coating tank in which a coating liquid for a charge generation layer is stored and the coating liquid always overflows, and gripping means for gripping a plurality of cylindrical base materials so as to be movable up and down. An apparatus for producing an electrophotographic photosensitive member for forming a charge generation layer by dip coating in which a cylindrical substrate is simultaneously dipped in the coating solution and pulled up,
The coating solution above the surface of the coating tank, each position of the gripped plurality of cylindrical base material, a lid in accordance with the number plurality of cylindrical air shielding device is gills Bei, and the coating liquid surface et disposed so as to completely cover the entire open surface of the coating tank at regular intervals which,
The coating liquid side end of the cylindrical wind shield projects from the bottom surface of the lid to the coating liquid surface side,
Production of an electrophotographic photosensitive member, characterized in that the interval between the coating liquid side end of the cylindrical wind shield and the coating liquid surface is equal to or less than the width of the non-image area on the coating liquid side in the photoreceptor after dip coating. Device.

  According to the electrophotographic photoreceptor manufacturing apparatus of the present invention, even when a plurality of cylindrical substrates are in a highly integrated density state, the distance from the coating liquid surface to the coating liquid side end of the hood is Since the width is less than the non-image area width at the lower end of the coating, it is possible to prevent mist generated after coating from adhering to the adjacent image area of the substrate, and to increase the yield rate of the final electrophotographic photoreceptor. Therefore, the electrophotographic photosensitive member can be produced industrially advantageously.

Hereinafter, the present invention will be described in detail.
The electrophotographic photoreceptor manufacturing apparatus of the present invention has at least a coating tank in which a coating solution is stored and the coating solution always overflows, and a gripping means for gripping a plurality of cylindrical substrates so as to be movable up and down. The photosensitive substrate is formed by dip coating by immersing and pulling up the plurality of cylindrical base materials simultaneously in the coating solution, and the plurality of cylindrical substrates gripped above the coating solution surface of the coating tank. A lid having a cylindrical wind shield corresponding to the position and number of each material is provided so as to cover the entire opening surface of the coating tank at a certain distance from the coating liquid surface. The distance between the coating liquid side end of the air blower and the coating liquid surface is less than the width of the non-image area on the coating liquid side in the photosensitive layer after dip coating.

  FIG. 1 is a schematic configuration diagram of an electrophotographic photoreceptor manufacturing apparatus according to the present invention. Around the coating tank 1, a liquid receiving portion 2 for receiving the coating liquid 6 overflowing from the opening surface of the coating tank 1 is provided, and a lid 3 is placed on the top. A hood 4 (cylindrical wind shield) is provided above the coating tank 1 in the drawing so that the lower end (coating liquid side end) protrudes from the bottom surface of the lid 3 toward the coating liquid surface. A cylindrical base material 5 is disposed above the coating tank 1 in the drawing so as to be movable in the vertical direction by gripping means (not shown). However, the present invention is not limited to the example shown in FIG. 1, and can be applied to a modified electrophotographic photosensitive member manufacturing apparatus without departing from the gist of the present invention.

  If the electrophotographic photosensitive member is formed using the electrophotographic photoreceptor manufacturing apparatus of the present invention, the distance between the lower end of the hood 4 (coating liquid side end) and the coating liquid surface (see FIG. 1) as in the prescribed condition. Since the cylindrical wind shield (hood 4) is provided so that D) in the photosensitive layer after dip coating is equal to or less than the width of the non-image area on the coating solution side, the cylindrical base material is the coating solution. The mist generated and scattered immediately after leaving the surface is shielded by the hood 4 in the image area portion of the photosensitive layer, and does not adhere to the wet film in the image area on the surface of the adjacent cylindrical base material. Never become.

The electrophotographic photoreceptor manufacturing apparatus of the present invention has a shape in which the lower end of the hood 4 protrudes from the bottom surface of the lid 3 toward the coating liquid as shown in FIG.

FIG. 2 shows a cylindrical base material coated with a photosensitive layer immediately after dip coating by the production apparatus of the present invention. The photosensitive layer after the dip coating is a state immediately after the cylindrical base material 5 is pulled up. The photosensitive layer 10 in a gripped state is referred to, and the non-image area width differs depending on the size of the cylindrical base material 5 used, the image forming apparatus used as the electrophotographic photosensitive member, and the image forming process. Although it cannot say, it says the area | region (range of B in FIG. 2) of the range about 2.5 to 6.0% of the longitudinal direction full length of a base material from the lower end part of the cylindrical base material 5 in FIG.

  In the present invention, the distance D between the lower end of the hood 4 and the coating liquid surface may be equal to or less than the non-image area of the photosensitive layer after coating, but 30 mm or less in order to satisfy an appropriate solvent vapor concentration and flow. Is preferable, and 15 mm or less is more preferable. Moreover, when the lower end of the hood 4 protrudes from the bottom surface of the lid 3 as described above, the length from the bottom surface of the lid 3 to the lower end of the hood 4 is preferably in the range of 5 to 30 mm for the same reason. The range of 5-20 mm is more preferable.

  The coating tank 1 is not particularly limited as long as it has a function capable of containing the coating liquid 6, and can be appropriately selected according to the purpose, such as material, shape, structure, size, and the like. The coating liquid 6 always overflows from the opening surface of the coating tank 1, and the coating layer (photosensitive layer) can be formed on the surface of the cylindrical substrate 5 by dipping and pulling up the cylindrical substrate 5 in the coating liquid 6.

Therefore, the coating tank 1 preferably has a liquid receiving part 2 for collecting or guiding the overflowing and overflowing coating liquid 6, and further temporarily stores the coating liquid 6 collected by the liquid receiving part 2. It is more preferable to have a storage tank that circulates and a coating liquid circulating means that circulates the coating liquid in the storage tank into the coating tank again. When the coating tank 1 has such a storage tank and a coating liquid circulating means, the coating liquid can be used effectively, and the influence of the coating liquid on the external environment can be reduced. Is advantageous.
In addition, as a circulation rate of a coating liquid, the range of 5-30 l / min is preferable, and the range of 8-20 l / min is more preferable.

  The said lid | cover 3 is provided with two or more corresponding to each position and the number of the some cylindrical base material 5 with which the hood 4 (cylindrical wind shield) was hold | gripped. The hood 4 may be detachably attached to the lid 3, but may be detachably provided. Here, according to the position and number of each of the plurality of cylindrical base materials 5, one cylindrical base material 5 is a hood for each gripped cylindrical base material 5. 4 is provided so as to be arranged in the central part.

  The connection between the hood 4 and the lid 3 is not particularly limited and is selected from known means, and examples thereof include fitting, screwing, engagement, and connection by an adhesive. In addition, the said hood 4 has a function which shields external wind so that the upwind direction of external wind may be covered.

In the present invention, since the coating film defect is less likely to occur due to the above-described conditions, the interval between the surfaces of the pipe (cylindrical base material 5) applied at a time is narrowed (highly integrated). Can do. The interval between the pipe surfaces is preferably in the range of 10 to 100 mm, and more preferably in the range of 20 to 80 mm. And when using the manufacturing apparatus of this invention, for example, the cylindrical base material 5 whose diameter is 30 mm is used, and the accumulation density is made into the range of about 50-300 piece / m < ² > about one coating layer 1. FIG. Is more preferable, and the range of about 100 to 250 / m ² is more preferable.

  The hood 4 constituting the main part of the present invention is made of a material that does not change by solvent vapor, for example, a metal material such as stainless steel or aluminum, or a plastic material such as polyethylene, polypropylene, or polyethylene terephthalate. Further, a part or the whole of the hood 4 may have a mesh structure.

  The gripping means has a function of gripping the cylindrical base material 5 so as to be movable up and down and immersing the cylindrical base material 5 in the coating liquid 6. The gripping means in the present invention grips a plurality of cylindrical base materials 5. Accordingly, the gripping means has a function of gripping the plurality of cylindrical base materials 5 so that they can be moved up and down at the same time, and immersing the plurality of cylindrical base materials 5 in the coating solution 6 at the same time. It is advantageous.

  The gripping means is not particularly limited as long as it has the above function and can be appropriately selected according to the purpose. For example, a gripping part that grips the cylindrical base material 5 and a moving part that moves the gripping part up and down A gripping means having

  The gripping portion is not particularly limited as long as it has a function capable of gripping the cylindrical base material 5. For example, a structure that grips the cylindrical base material 5 in close contact with the inner surface of the cylindrical base material 5, for example, an arm Examples include a base material holder connected to the structure, a structure for sandwiching the cylindrical base material 5, such as a clip, an adhesive body for attaching the object to be processed, a chuck device, and the like. Among these, the structure that holds the cylindrical base material 5 in close contact with the inner surface of the cylindrical base material 5 is not in contact with the outer surface of the cylindrical base material 5, which is advantageous for the convenience of forming a coating film.

  The moving unit is not particularly limited as long as it has a function capable of moving the cylindrical base material 5 so that it can be moved up and down. For example, the moving unit may be a vertically standing bar body and a driving source such as a motor. A structure having a structure that moves up and down on the peripheral side surface, such as a lifting motor and a pole screw, and a bar body that is erected vertically and designed to be stretchable by a driving source such as a motor. Can be mentioned. The grip portion is connected to the moving portion. The operation of the drive source can be controlled using a control means such as a computer.

  The generation of the mist in the present invention also depends on the pulling speed of the cylindrical base material 5, and the lower the pulling speed, the more the cylindrical base material 5 moves away from the coating liquid surface, and then the bottom of the cylindrical base material. A liquid film is easily formed on the opening surface, which causes mist generation. The production apparatus of the present invention is capable of coating a photosensitive layer without causing coating film defects even under conditions where mist is likely to occur, and the lifting speed by the moving part is 10 to 250 mm / The range of sec is preferable, and the range of 100 to 150 mm / sec is more preferable.

  The electrophotographic photosensitive member manufacturing apparatus shown in FIG. 1 operates as follows. That is, first, the cylindrical base material 5 is held by a holding tool (not shown). When an elevator motor (not shown) is driven, the cylindrical base material 5 moves downward in the drawing. Below the cylindrical base material 5, an application tank 1 for storing the coating liquid 6 is opened, and the cylindrical base material 5 is immersed in the coating liquid 6. At this time, the coating liquid 6 overflowing and overflowing from the coating tank 1 is collected by the liquid receiving portion 2, guided by the guide tube 7, and once stored in a storage tank (not shown). At this time, the space between the coating liquid surface and the lid 3 is filled with the solvent vapor 9 of the coating liquid 6.

  Next, when the elevator motor is driven in reverse, when the cylindrical base material 5 moves upward in the drawing, the cylindrical base material 5 comes out of the coating liquid in the coating tank 1. At this time, since the amount of the coating liquid 6 in the coating tank 1 is reduced by the amount overflowing earlier, the pump is driven and the coating liquid 6 contained in the storage tank is passed through the pipe 8. To circulate in the coating tank 1. As a result, the amount of the coating liquid 6 in the coating tank 1 is controlled to be constant.

When the cylindrical base material 5 comes out of the coating tank 1, the cylindrical wind shield 4 is disposed outside the cylindrical base material 5 so as to cover the upwind direction of the outside wind. The outside wind is shielded, and the coated surface of the cylindrical base material 5 is dried without being affected by the outside wind. Further, since the distance D between the coating liquid side end of the cylindrical wind shield 4 and the coating liquid surface is set to be equal to or less than the non-image area width of the photosensitive layer in the cylindrical base material 5, even when mist is generated, the distance D is adjacent. A coating film defect is not caused in the image area corresponding portion of the photosensitive layer of the cylindrical substrate 5.
As a result, according to the electrophotographic photoreceptor manufacturing apparatus of the present invention, a coating film having a uniform film thickness without coating film defects can be rapidly formed without being affected by external wind.

Next, actual production of an electrophotographic photoreceptor using the electrophotographic photoreceptor production apparatus of the present invention will be described.
The dip coating by the production apparatus of the present invention can be carried out under the same conditions as those for producing an electrophotographic photoreceptor using a conventional dip coating tank apparatus, except that the conditions on the production apparatus are used. In that case, the produced electrophotographic photosensitive member is a laminate type in which the coating film is composed of a charge generation layer and a charge transport layer. There is a remarkable effect in preventing film defects, whereby an excellent electrophotographic photoreceptor can be produced. The above-mentioned laminated type photoconductor is not only a negatively charged photoconductor that is formed by laminating a charge generation layer and a charge transport layer in this order on the surface of a conductive substrate (cylindrical substrate), but also charge transport to the surface of a conductive substrate. A positively charged photoreceptor in which a layer and a charge generation layer are laminated in this order can also be preferably produced.

The electrophotographic photosensitive member is formed, for example, by laminating an undercoat layer, a charge generation layer, a charge transport layer, and the like on the surface of a conductive substrate (cylindrical substrate).
Examples of the material of the cylindrical substrate that is the conductive substrate include metal materials such as aluminum, stainless steel, and nickel, polymer materials such as polyethylene terephthalate, polybutylene terephthalate, polypropylene, nylon, polystyrene, and phenol resin, and hard paper. Examples thereof include a method in which a conductive substance is dispersed as a conductive treatment in an insulating material such as a metal foil, a metal foil, and a metal vapor deposition method.
As for the magnitude | size of the said cylindrical base material, a diameter is 10-300 mm normally, and length is 20-1000 mm.

  As the undercoat layer, various resins such as acrylic, methacrylic, vinyl chloride, vinyl acetate, epoxy, polyurethane, phenol, polyester, alkyd, polycarbonate, silicon, melamine, and zirconium Examples thereof include compounds formed from the above-mentioned resins containing a compound or a titanium compound.

  The thickness of the undercoat layer is preferably in the range of 0.05 to 10 μm, particularly preferably in the range of 0.1 to 2 μm. When the photosensitive layer has a laminated structure of a charge generation layer and a charge transport layer, any of them may be provided on the undercoat layer.

  Examples of the charge generation material contained in the charge generation layer include azo pigments, disazo pigments, quinone pigments, quinocyanine pigments, perylene pigments, indigo pigments, bisbenzimidazole pigments, phthalocyanine pigments, quinacridone pigments, pyrylium salts, azulenium salts, tricrystals. For example, square selenium.

  Among these, a phthalocyanine pigment is preferable in terms of photosensitivity, electrical property stability, and image quality, and examples of the phthalocyanine pigment include metal-free phthalocyanine, halogenated gallium phthalocyanine such as chlorogallium, and halogenated tin phthalocyanine such as dichlorotin, Examples thereof include hydroxygallium phthalocyanine, oxytitanyl phthalocyanine, halogenated indium phthalocyanine such as chloroindium, and vanadyl phthalocyanine.

  Examples of the binder resin used in the charge generation layer include polycarbonate, polyarylate, polystyrene, polymethacrylic acid esters, styrene-methyl methacrylate copolymer, polyester, styrene-acrylonitrile copolymer, polysulfone, polyvinyl acetate, Examples include acrylonitrile, polyvinyl butyral, polyvinyl pyrrolidone, methyl cellulose, hydroxymethyl cellulose, and cellulose esters.

  The content of the charge generation material in the charge generation layer is usually in the range of 30 to 500 parts by mass with respect to 100 parts by mass of the binder. The thickness of the charge generation layer is usually in the range of 0.05 μm to 1 μm, particularly preferably 0.1 to 0.5 μm. In particular, the coating film defect of the photosensitive layer is likely to occur when a thin film layer such as the charge generation layer is formed.

  Various additives such as a leveling agent, an antioxidant and a sensitizer for improving the coating property can be added to the charge generation layer as necessary. The charge generation layer may be a layer formed by binding fine particles of the charge generation material in a state of being dispersed in the binder, or may be a vapor deposition film of the charge generation material.

  Examples of the charge transport material contained in the charge transport layer include polycyclic aromatic compounds such as anthracene, pyrene, phenanthrene and coronene in the main chain or side chain, or indole, carbazole, oxazole, isoxazole, thiazole, imidazole, pyrazole, oxalate. Examples thereof include compounds having a skeleton of a nitrogen-containing cyclic compound such as diazole, pyrazoline, thiadiazole and triazole, and hole transport materials such as hydrazone compounds.

  Examples of the binder used in the charge transport layer include those exemplified as the binder resin used in the charge generation layer.

As content of the said charge transport substance in the said charge transport layer, it is the range of 30-200 mass parts normally with respect to 100 mass parts of said binders, and the range of 40-150 mass parts is preferable. The thickness of the charge transport layer is usually in the range of 5 to 50 μm, and preferably in the range of 15 to 30 μm.
In order to improve the film formability, flexibility, coatability, etc., additives such as known plasticizers, antioxidants, ultraviolet absorbers, leveling agents and the like are added to the charge transport layer as necessary. Can do.

In the electrophotographic photoreceptor, an outermost surface layer may be further provided on the surface of the photosensitive layer, and as such an outermost surface layer, for example, a conventionally known thermoplastic or thermosetting polymer is mainly used. An overcoat layer etc. are mentioned.
The electrophotographic photoreceptor manufacturing apparatus of the present invention may be used for forming the outermost surface layer.

  As the coating solution solvent (solvent), a solvent having high volatility and a vapor density larger than that of air is preferably used. For example, n-butylamine, diethylamine, ethylenediamine, isopropanolamine, triethanolamine, N, N-dimethylformamide, acetone, methyl ethyl ketone, cyclohexanone, benzene, 4-methoxy-4-methylpentanone, dimethoxymethane, dimethoxyethane, 2,4-pentadione, anisole, methyl 3-oxobutanoate, monochlorobenzene, toluene, xylene, Chloroform, 1,2-dichloroethane, dichloromethane, tetrahydrophthalane, dioxane, methanol, ethanol, isopropanol, 1-butanol, ethyl acetate, butyl acetate, dimethyl sulfoxide, methyl cello Lube, ethyl cellosolve, and the like methyl cellosolve acetate.

  Among these solvents, the mist is likely to be generated when a solvent having a slow evaporation rate (boiling point of 120 ° C. or more) is used. Even in such a case, if the production apparatus of the present invention is used, the photosensitive layer is coated. It is possible to prevent film defects.

In the electrophotographic photoreceptor manufacturing apparatus of the present invention, the coating solution to be dip-coated on the surface of the conductive substrate can be obtained by dissolving or dispersing each substance to be contained in each layer in the above solvent.
The viscosity of the coating solution used in the present invention is preferably in the range of 0.001 to 1 Pa · s, and more preferably in the range of 0.002 to 0.8 Pa · s. The viscosity can be measured using a normal rotational viscometer.

  The surface tension of the coating solution used in the present invention is preferably in the range of 20 to 30 mN / m, and more preferably in the range of 22 to 26 mN / m. The surface tension can be measured using a Wilhelmy type surface tension meter (plate method).

  In order to produce an electrophotographic photoreceptor using the electrophotographic photoreceptor production apparatus of the present invention, the undercoat layer coating solution, the charge generation layer coating solution, the charge transport layer coating solution, and the like are applied as a coating solution. As described above, the conductive substrate surface may be sequentially dip coated and dried.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated more concretely, this invention is not limited to this. In addition, the structural formulas (1) to (6) of the compounds used in the following Examples and Comparative Examples and the composition of the coating solution are as follows.

-Coating liquid A (coating liquid for undercoat layer)-
-20 parts by mass of the zirconium compound of structural formula (1)-2 parts by mass of the silane coupling agent of structural formula (2)-2 parts by weight of polyvinyl butyral of structural formula (3)-70 parts by mass of 1-butanol The solution was dissolved as coating solution A.

-Coating solution B (coating solution for charge generation layer)-
-5 parts by mass of chlorogallium phthalocyanine-5 parts by mass of vinyl chloride-vinyl acetate copolymer of structural formula (6)-200 parts by mass of n-butyl acetate The above components are dispersed in a sand mill using glass beads with a diameter of 1 mm for 2 hours. The dispersion liquid obtained in this manner was used as coating liquid B. The coating solution B had a viscosity of 5 mPa · s and a surface tension of 23 mN / m.

-Coating liquid C (coating liquid for charge transport layer)-
-1 part by weight of charge transport material of structural formula (4)-1 part by weight of polycarbonate resin of structural formula (5)-2 parts by weight of monochlorobenzene-4 parts by weight of tetrahydrofuran Mixing and dissolving the above components together with coating solution C did.

Example 1
An aluminum cylindrical substrate having a diameter of 30 mm and a length of 340 mm with an arithmetic surface roughness Ra of 0.2 μm by wet honing is applied to a coating liquid A (undercoat layer) using a normal dip coating apparatus. ), The coating was applied at a pulling speed such that the dry film thickness was 1.0 μm, and was naturally dried for 2 minutes. Next, the coating liquid B (charge generation layer) was applied at a lifting speed of 180 mm / sec using the dip coating apparatus of the present invention shown in FIG. 1, and the dry film thickness was 0.2 μm on the surface of the undercoat layer. The charge generation layer was formed.

  When the charge generation layer is applied, the number of the cylindrical base materials 5 to be applied at the same time is six, and the arrangement in which these are gripped by the gripping tool is a view seen from the end face side of the cylindrical base material 5 in FIG. The arrangement was as follows. Further, the opening surface of the coating tank 1 is 140 × 210 mm, and the lid 3 provided with the six cylindrical hoods 4 corresponding to the positions of the six cylindrical base materials 5 is provided above the coating liquid surface. It is installed so as to cover the opening surface of the tank 1. Each hood has an opening surface diameter of 60 mm, and is arranged so that each cylindrical base material 5 enters the center, and the interval between each pipe (cylindrical base material 5) is 70 mm. In addition, the length of each hood 4 above the lid 3 in the drawing is 200 mm, and the length below the lid 3 in the drawing is 15 mm. The distance D between the coating liquid side end of the hood 4 and the coating liquid surface is set to be 10 mm.

In addition, as shown by the cylindrical base material 5 on which the photosensitive layer 10 after the dip coating of FIG. 2 is formed, the non-image area width (lower end side of the dip coating) B of the electrophotographic photoreceptor used in this example is 12 mm. The image area width A is 313 mm.
A total of 60 samples were produced by the above method. As a result of visually observing the image area of each prepared sample and evaluating the presence or absence of a repellency-like coating film defect, no repellency failure occurred in the image area.

Furthermore, using a normal dip coating apparatus, the coating liquid C (coating liquid for charge transport layer) is dip coated at a pulling rate such that the dried film thickness after drying is 20 μm on the surface of the charge generation layer, It was naturally dried for 2 minutes and dried at 135 ° C. for 60 minutes.
Thus, the electrophotographic photosensitive member 1 was manufactured.

(Comparative Example 1)
In the embodiment, when the charge generation layer is formed, the electrophotographic photosensitive member 2 is formed in the same manner as in the embodiment 1 except that the distance D between the coating liquid side end of the hood 4 and the coating liquid surface in FIG. 1 is set to 15 mm. Produced. In this comparative example, when a total of 60 samples after the application of the charge generation layer were evaluated, 6 repelling failures occurred in the image area.

(Comparative Example 2)
In the embodiment, when the charge generation layer is formed, the electrophotographic photosensitive member 3 is formed in the same manner as in the embodiment 1 except that the distance D between the coating liquid side end of the hood 4 and the coating liquid surface in FIG. 1 is set to 30 mm. Produced. In this comparative example, when a total of 60 samples after application of the charge generation layer were evaluated, 19 repelling failures occurred in the image area.

  All of the electrophotographic photoreceptors 1 to 3 obtained in Example 1 and Comparative Examples 1 and 2 were mounted on a digital color printer (DocuPrint C2426, manufactured by Fuji Xerox Co., Ltd.) and image evaluation was performed. As a result, in the electrophotographic photosensitive member 1, there was no problem in terms of all the 60 images. However, in the electrophotographic photosensitive members 2 and 3, all the half-tone and full-surface solids in which the charge generation layer was repelled occurred. In the image, image defects based on repelling were seen.

  From this result, the electrophotographic photoreceptor manufacturing apparatus of the present invention has a high shielding property against mist even in dip coating under the condition that the solvent evaporation rate is relatively slow as in the formation of a charge generation layer. It was clear that a photosensitive layer free from coating film defects in the image area can be formed on a plurality of cylindrical substrates with high integration density.

1 is a schematic partial cross-sectional view showing an example of an apparatus for producing an electrophotographic photosensitive member of the present invention. It is a figure which shows the cylindrical base material with which the photosensitive layer after dip coating was apply | coated. It is the figure which looked at the state which grasped the cylindrical base material from the opening side of the base material.

Explanation of symbols

1 Coating tank 2 Liquid receiving part 3 Lid 4 Hood (cylindrical wind shield)
5 Cylindrical base material 6 Coating solution 7 Guide tube 8 Piping 9 Solvent vapor 10 Photosensitive layer

Claims (1)

At least a coating tank in which the coating liquid for the charge generation layer is stored and the coating liquid always overflows; and a gripping means for gripping the plurality of cylindrical base materials so as to be movable up and down. An apparatus for producing an electrophotographic photosensitive member for forming a charge generation layer by dip coating in which a material is simultaneously immersed in the coating solution and pulled up,
A lid provided with a plurality of cylindrical wind shields corresponding to the position and number of each of the gripped cylindrical substrates above the coating liquid surface of the coating tank is constant with the coating liquid surface. provided al is so at intervals to completely cover the entire open surface of the coating bath,
The coating liquid side end of the cylindrical wind shield projects from the bottom surface of the lid to the coating liquid surface side,
Production of an electrophotographic photosensitive member, characterized in that the interval between the coating liquid side end of the cylindrical wind shield and the coating liquid surface is equal to or less than the width of the non-image area on the coating liquid side in the photoreceptor after dip coating. apparatus.

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