JP2006259053A - Spray coating apparatus for parts of electrophotographic apparatus and method for manufacturing electrophotographic photoreceptor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spray coating apparatus for parts of an electrophotographic apparatus capable of stably forming a uniform coating film on an object to be coated without coating defects which are caused by scum of a coating liquid which adheres to a nozzle tip of a spray gun, dries, drops during spray coating and adheres to the object to be coated, and to provide a method for manufacturing an electrophotographic photoreceptor. <P>SOLUTION: In the spray coating apparatus for parts of an electrophotographic apparatus for forming a coating film on an object to be coated in a coating booth, a spray gun is equipped with a coating material nozzle and an air cap configured such that a coating liquid and atomizing air are fed, respectively, and a needle in the coating material nozzle, wherein the coating material nozzle has a passage for feeding the coating liquid and a discharge port, the spray gun has an air feeding path for feeding atomizing air and an exhaust port between the air cap and the coating material nozzle, and mutual relationships among the coating material nozzle, the air cap and the needle, dimensions, etc., (H, θ, t, 9(c), h, 10(m), T, and D/T in the figure and surface roughness) are adjusted. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a spray coating apparatus for parts of an electrophotographic apparatus, and more specifically, spray coating used for manufacturing parts for an electrophotographic apparatus such as an electrophotographic photosensitive member, a transfer roller, a transfer belt, a fixing roller, or a fixing belt. The present invention relates to an apparatus and a method for producing an electrophotographic photosensitive member using the apparatus.

  Electrophotographic photoreceptors include inorganic photoreceptors using amorphous silicon and the like, and organic photoreceptors using an organic photoconductor (hereinafter abbreviated as “OPC”). OPC can be manufactured by coating, and its properties can be controlled by the composition of the coating film and the components and thickness of each coating film, so it is widely used. In this OPC, a photosensitive layer is formed on a conductive substrate by coating. So-called dipping method and spray coating method are used as the coating method. An undercoat layer, a charge generation layer and a charge transport layer are formed by dip coating, and a protective layer is formed thereon by spray coating.

  Spray coating is used in the manufacture of OPCs in this way, but it is also used in the manufacture of other parts of electrophotographic devices, such as transfer rollers, transfer belts, fixing rollers, fixing belts, etc. In recent years, since a coating film can be formed with a small amount of coating liquid compared to the above, it has been widely used in recent years.

  Spray guns that perform spray coating are produced according to the required quality by combining the liquid discharge amount and atomizing air amount using a commercially available standard nozzle, but products such as electrophotographic photoreceptors are used. For small size products, intermittent spraying is unavoidable, so the nozzle tip is easy to dry, and the adhering / dried coating liquid drops off the nozzle tip and adheres to the coating surface. There has been a problem of cost reduction and cost increase.

  FIG. 13 shows the tip shape of a general spray gun. According to such a spray gun, the coating liquid adheres to the nozzle discharge port or the like due to the turbulent flow or entrainment of the atomizing air, and the coating liquid crystal grows. Also, film thickness defects occur due to nozzle clogging or spray pattern deformation. This phenomenon is particularly strong in the case of a dispersion pigment liquid. In addition, there is a problem that the coating liquid mist diameter does not match the target particle diameter, the coating film surface roughness is out of specification, and the image becomes abnormal as a foreign matter defect. In this case as well, although depending on the liquid property, such a phenomenon tends to appear strongly in a solution having a viscosity of 50 CPS or more.

  Conventionally, as countermeasures against nozzle clogging, there are proposals such as placing the nozzle tip in a solvent atmosphere or providing an ultrasonic cleaning mechanism (see, for example, Patent Document 1). However, this scheme complicates the mechanism and has the problem that production must be stopped during nozzle cleaning. Further, since the spray nozzle is made of metal, there is a problem that metal ions are contained in the discharge liquid and remain in the coating film, resulting in image defects.

  On the other hand, as a method of eliminating the nozzle tip contamination of the spray gun, a method is proposed in which a cap is applied to the tip of the spray gun after the coating film is formed, and cleaning liquid is introduced from the nozzle through the air ejection hole to clean the inner and outer surfaces of the nozzle tip. However, since a jig for cleaning is required and further cleaning time is required, productivity is lowered and manufacturing cost is increased.

  Further, in order to prevent solidification and alteration of the water-based emulsion adhering to the tip portion of the spray gun, a method of making the diameter of the atomizing air nozzle 4 to 10 times the inner diameter of the paint nozzle (for example, see Patent Document 3), and paint There has been proposed a method of preventing the paint from adhering to the tip of the injection port so that the paint solidified in the form of particles does not fly (see, for example, Patent Document 4).

  However, none of the above methods is effective as a method for preventing the coating material from adhering to the tip portion of the spray gun or the coating material injection port, and the coating material cannot be completely eliminated. For this reason, under the influence of the paint which has adhered, the problem that the uniformity of the formed coating film is inferior arises.

In addition, a method has been proposed in which a nozzle is always washed with a solvent by mixing a solvent into the atomizing air, and a uniform coating film is obtained so that the paint does not adhere to the nozzle tip and solidify (for example, Patent Documents). 5). However, this method has a problem that the atomization of the coating liquid becomes insufficient and the uniformity of the coating film is inferior.
JP-A-4-362951 JP 2003-2111064 A JP-A-8-221707 Japanese Patent Laid-Open No. 11-114458 JP 2003-122035 A

  In recent years, electrophotographic photoreceptors used for copying machines, printers, and the like are required to have very high uniformity due to high image quality. On the other hand, the spray coating device is not only an electrophotographic photosensitive member, but also spray coating when manufacturing parts for an electrophotographic device such as a transfer roller, a transfer belt, a fixing roller, or a fixing belt used in the electrophotographic device. The coating film formation by is performed and the use is wide.

  The present invention has been made in view of the above circumstances, and in manufacturing parts for an electrophotographic apparatus such as an electrophotographic photosensitive member by spray coating, the coating liquid adhering to the nozzle tip of the spray gun is dried. Spray for parts of electrophotographic equipment that can be stably formed with a coating film without any coating defects caused by falling off during spray coating and adhering to the coating object. It is an object of the present invention to provide a coating apparatus and a method for producing an electrophotographic photosensitive member using the same.

  In order to solve the above-mentioned problems, the invention according to claim 1 is applied from a spray gun attached to a guide rail so as to be movable in the axial direction of the application object while rotating the application object in the application booth. A spray coating device for parts of an electrophotographic apparatus for spraying a liquid to form a coating film on an object to be coated, wherein the spray gun is configured to feed the coating liquid and atomizing air, respectively. The paint nozzle includes a nozzle, an air cap, and a needle in the paint nozzle. The paint nozzle has a flow path and a discharge port for feeding the coating liquid, and atomized air is supplied between the air cap and the paint nozzle. It has an air feed path for feeding and a discharge port, and further, the front end of the air cap and the front end of the paint nozzle are configured so that one of them is the front surface with a difference of ± 0.3 mm.

  According to a second aspect of the present invention, in the spray coating apparatus for parts of the electrophotographic apparatus according to the first aspect, the outer taper angle (θ) of the nozzle tip of the spray gun is in the range of 15 to 45 degrees. The thickness (t) of the nozzle outlet of the spray gun should be 0.1 mm or more and 0.5 mm or less, and the gap (c) where the paint nozzle and the needle of the spray gun are in contact with the outside air should be 0.1 mm or less. , Make the tip of the spray gun needle protrude from 0.1 mm to 2 mm from the tip of the paint nozzle, chamfer the corner of the paint nozzle tip of the spray gun, each of the paint nozzle discharge port, air cap, and needle tip of the spray gun The material shall be trifluoroethylene chloride, polypropylene, cemented carbide, respectively SUS, SUS, PEEK, spray gun The clearance (T) between the inner wall of the air cap and the outer wall of the paint nozzle is 0.15 mm or more and 1.0 mm or less, the outer diameter D of the paint nozzle of the spray gun, and the clearance T between the inner wall of the air cap and the outer wall of the paint nozzle The ratio (D / T) of 0.1 to 1.0 and at least one of the surface roughness of the wall surface of the paint nozzle tip of the spray gun and the inner wall of the air cap is 1.6 to 6.3 S. It further has one.

  According to a third aspect of the present invention, using the electrospray device part spray coating apparatus according to the first or second aspect, the coating liquid is fed and discharged from the flow path and the discharge port of the paint nozzle. A method for producing an electrophotographic photosensitive member, characterized in that atomized air is fed and discharged from a gap between an air cap and a paint nozzle and a discharge port, and a coating liquid is sprayed and applied onto a substrate.

  According to a fourth aspect of the present invention, in the electrophotographic photosensitive member manufacturing method according to the third aspect, the atomizing air pressure of the spray gun is 20 to 100 KPa, and the liquid discharge amount is 1 to 50 cc / min. It is characterized by being.

  According to the spray coating apparatus for parts of the electrophotographic apparatus of the present invention, since the positional relationship and dimensions of each part of the spray gun are optimally adjusted, the coating liquid discharged from the discharge port of the paint nozzle and the fog of the air cap The atomized air discharged from the atomizing air outlet is uniformly mixed, and the mist particle size is equalized. In addition, turbulence and stagnation are eliminated in the air flow in the vicinity of the paint nozzle discharge port, and the coating liquid is prevented from adhering to the surface adjacent to the paint nozzle discharge port. There is no coating defect to be generated, and a uniform coating film can be stably formed on an object to be coated.

  Further, according to the method for producing an electrophotographic photosensitive member of the present invention, the electrophotographic photosensitive member is produced by spraying and applying the coating solution onto a substrate with the above-described component spray coating apparatus of the electrophotographic device. There is no adhesion of liquid residue to the surface in contact with the outside air near the discharge port of the paint nozzle and the surface adjacent to the discharge port.Therefore, there is no coating defect caused by dropping or adhesion of the liquid residue. The coating liquid discharged from the discharge port and the atomized air discharged from the atomizing air discharge port of the air cap are uniformly mixed, and the mist particle size is equalized, so that a uniform coating film can be stabilized on the substrate. Can be formed.

  Next, an embodiment of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a schematic view showing an example of a spray coating apparatus for parts of an electrophotographic apparatus of the present invention.

  As shown in FIG. 1, an object to be coated (work in the figure) 51 is rotatably arranged in a coating booth 52, while the spray gun 53 is movable along the axial direction of the work 51. It is attached to the guide rail 54. The coating booth 52 is provided with a clean air supply port 55 and an exhaust port 56 in order to eliminate excess spray mist sprayed from the spray gun 53. Then, the application liquid is supplied from the application liquid tank 58 by the pump 59, and the atomization air is supplied from the atomization air tank 61 by the pump 62, and the application liquid is atomized and sprayed from the spray gun 53 onto the work 51. .

  FIG. 2 is a schematic sectional view showing a spray gun in the spray coating apparatus for parts of the electrophotographic apparatus of the present invention.

  As shown in FIG. 2, the spray gun 1 has a paint nozzle 2 and an air cap 3 configured to feed a coating liquid and atomized air, respectively, and a needle 4 is provided in the paint nozzle 2. Is provided. The nozzle 2 is provided with a flow path 20 for supplying a coating liquid and a discharge port 5, and an air supply path 30 for supplying atomized air and a discharge port 6 between the air cap and the nozzle. Is provided.

  The spray gun 1 according to the present invention has the above-described configuration, and further the paint nozzle is controlled so that adhesion of liquid residue to the surface in contact with the outside air near the discharge port of the paint nozzle 2 and the surface adjacent to the discharge port is suppressed. 2, the positional relationship and dimensions of the air cap 3 and the needle 4 are preferably adjusted. Further, the atomizing air pressure and the liquid discharge amount of the spray gun are optimally adjusted, so that spraying with a preferable mist particle size is performed.

  The preferred positional relationship and the like will be sequentially described below.

  First, as shown in FIG. 3, it is preferable that one of the front end of the air cap 3 and the front end of the paint nozzle be a front surface with a difference (H) of ± 0.3 mm. Therefore, when sprayed air (atomized air) flow from the gap of the air cap 3 is discharged during spray coating, turbulent flow and entanglement at the discharge port 6 are eliminated, and thereby the paint nozzle discharge port 5 is discharged. The adhesion of the coating liquid to the adjacent surfaces 7 and 8 is eliminated, and it is possible to prevent the occurrence of coating film defects due to the dropping of liquid residue from the surfaces 7 and 8 adjacent to the paint nozzle discharge port 5.

  If the position difference (H) between the tip of the air cap 3 and the tip of the paint nozzle 2 is outside the range of −0.3 mm or more and 0.3 mm or less, liquid residue is easily attached. That is, when the tip of the air cap 3 protrudes more than 0.3 mm from the tip of the paint nozzle, the coating liquid adheres to the surfaces 7 and 8 adjacent to the discharge port 5 and is adjacent to the discharge port 5 during spray coating. As a result, coating film defects are generated due to dropping off of liquid residue from the surfaces 7 and 8, and the yield rate is likely to decrease. On the other hand, when the air cap 3 is retracted more than 0.3 mm from the paint nozzle 2, the mist particle size at the time of spray coating varies, resulting in poor surface properties of the coating film, and variations in film thickness. Defects are likely to occur.

  The difference (H) in the position between the tip of the air cap 3 and the tip of the paint nozzle is more preferably ± 0.03 mm. The concentration of the coating solution is 0.5% to 35%, preferably 1.5% to 15% in terms of solid content.

  In addition to the positional relationship between the air cap 3 and the paint nozzle 2, the outer taper angle (θ) of the paint nozzle tip of the spray gun 1 is set to a range of 15 to 45 degrees as shown in FIG. It is preferable.

  By doing so, the coating liquid discharged from the paint nozzle discharge port 5 and the atomized air (compressed air) discharged from the atomized air discharge port 6 of the air cap are uniformly mixed, and the mist. The particle size can be equalized. Further, turbulence and stagnation are eliminated in the airflow in the vicinity of the paint nozzle discharge port 5, and the application liquid is suppressed from adhering to the surfaces 7 and 8 adjacent to the paint nozzle discharge port 5. If the outer taper angle θ of the coating nozzle tip is outside 15 to 45 degrees, it becomes difficult to equalize the mist particle diameter.

  A more preferable range of the outer taper angle (θ) of the paint nozzle tip is 25 to 35 degrees.

  Further, in addition to the positional relationship between the air cap 3 and the paint nozzle 2, the thickness (t) at the tip of the paint nozzle discharge port 5 of the spray gun is 0.1 mm or more and 0.5 mm as shown in FIG. The following is preferable.

  In this way, when the compressed air flow from the gap of the air cap 3 is discharged, the occurrence of entrainment at the tip of the paint nozzle discharge port 5 is suppressed, and the coating liquid adheres to the discharge port 5 due to the occurrence of entrainment. Less. Therefore, the coating crystal does not grow, and the detachment of the coating crystal over time can be eliminated to improve the coating quality and the yield rate. If the wall thickness t at the tip of the coating nozzle discharge port 5 deviates from 0.1 mm to 0.5 mm, the liquid residue tends to adhere.

  A more preferable range of the thickness (t) at the tip of the paint nozzle discharge port 5 is 0.1 mm or more and 0.2 mm or less.

  In addition to the positional relationship between the air cap 3 and the paint nozzle 2, the gap 9 where the paint nozzle 2 and the needle 4 of the spray gun are in contact with the outside air as shown in FIG. Is preferred.

  By doing so, it is possible to suppress accumulation of liquid residue in the gap 9 where the paint nozzle 2 and the needle 4 that increase over time by spray coating are in contact with the outside air, and during spray coating The liquid residue can be prevented from falling off, and the coating film quality and the yield rate can be improved.

  If the gap 9 where the paint nozzle 2 and the needle 4 are in contact with the outside air is larger than 0.1 mm, the paint nozzle 2 and the needle 4 will be in the outside air even if the tip of the nozzle is wiped and washed before the start of spray coating. The liquid residue deposited in the gap 9 in contact with the substrate cannot be completely removed, and the liquid residue is removed by spray coating, resulting in a coating film defect.

  Further, in addition to the positional relationship between the air cap 3 and the paint nozzle 2, as shown in FIG. 7, the position of the paint nozzle tip and the needle tip of the spray gun differs by 0.1 mm or more and 2 mm or less. Preferably protrudes.

  By projecting the tip of the needle with such a difference (h), straightness is obtained in the atomized air (compressed air) discharged from the discharge port 6 of the air cap, thereby stabilizing the spray pattern, A coating film having a uniform thickness is obtained, and the adhesion efficiency of the coating liquid is improved.

  If the difference (h) between the paint nozzle tip of the spray gun and the needle tip is smaller than 0.1 mm or larger than 2 mm, a uniform coating film cannot be obtained.

  A more preferable range of the position difference between the paint nozzle tip and the needle tip is 1 mm or more and 1.6 mm or less.

  In addition to the positional relationship between the air cap 3 and the paint nozzle 2, the corner 10 of the spray nozzle tip of the spray gun is chamfered between 0.05 mm and 0.1 mm as shown in FIG. It is preferable that

  Such chamfering eliminates turbulence and stagnation in the spray mist composed of the coating liquid discharged from the coating nozzle discharge port 5 and the compressed air discharged from the gap between the air cap 3 and the coating nozzle 2. Adhesion of the coating liquid that increases with time to the nozzle tip is suppressed, and variation in the discharge amount due to clogging of the paint nozzle discharge port 5 is suppressed, so that a uniform film thickness can be obtained.

  If the chamfer at the corner portion of the paint nozzle is smaller than 0.05 mm or larger than 0.1 mm, the chamfering effect is not obtained.

  In addition to the positional relationship between the air cap 3 and the paint nozzle 2, the spray nozzle paint nozzle, air cap, and needle materials may be trifluoroethylene chloride, polypropylene, cemented carbide, SUS, SUS, and PEEK are preferable.

  Note that SUS is stainless steel, and austenitic stainless steel (JIS symbol SUS304, SUS316) was used in the present invention. PEEK is a polyetheretherketone. The cemented carbide is an alloy in which a hard carbide containing tungsten carbide (WC) as a main component and containing a small amount of tantalum carbide (TaC), if necessary, is bonded with a metal such as cobalt (Co) or nickel (Ni).

  In the maintenance and inspection work of the spray gun, the fine powder generated by the removal and attachment of the above-mentioned members adheres to the coating film surface or the coating film surface, or is contained in the discharge liquid as metal ions and remains in the coating film. However, combining the spray nozzle paint nozzle 2, air cap 3, and needle 4 with synthetic resin and metal with good wear resistance, solvent resistance, and machinability. Therefore, it exerts an excellent power for solving the above problems.

  As a preferred material, the air cap 3 can be made of a polyacetal resin in addition to a PEEK material having good wear resistance, solvent resistance, and machinability. The coating nozzle 2 is preferably a fluororesin such as a trifluoroethylene chloride resin. The needle 4 is preferably made of a hard material such as a cemented carbide when a pigment-based dispersion is used. However, in the case of worrying about liquid leakage or a completely consumable product, a SUS material or a SUS material. It is also possible to attach a solvent-resistant resin such as a fluororesin or a polyethylene resin to the tip. The spray gun body may be made of an aluminum alloy or stainless steel in addition to a solvent-resistant resin such as a trifluorochloroethylene resin.

  In addition to the positional relationship between the air cap 3 and the paint nozzle 2, the gap T between the air cap inner wall and the paint nozzle outer wall of the spray gun is set to 0.15 mm to 1.0 mm as shown in FIG. It is preferable that

  By doing so, when the compressed air flow is discharged from the gap of the air cap at the time of spray coating, turbulent flow and entrainment are eliminated by ensuring an optimal discharge speed at the discharge port 6. This prevents the coating liquid from adhering to the surfaces 7 and 8 adjacent to the paint nozzle discharge port 5, thereby preventing the occurrence of coating film defects due to dropping off of the liquid residue. Further, it is possible to prevent liquid residue from adhering to the surface in contact with the outside air near the paint nozzle discharge port during spray coating.

  When the gap T is larger than 1.0 mm, the coating liquid adheres to the surfaces 7 and 8 adjacent to the paint nozzle discharge port 5 due to the turbulent flow or the entrainment of the compressed air flow, and the surface adjacent to the paint nozzle discharge port 5. A coating film defect due to dropping off of liquid residue from 7 and 8 occurs, and the yield rate decreases. On the other hand, when the gap T is smaller than 0.1 mm, the mist particle size at the time of spray coating varies due to insufficient flow rate of compressed air, resulting in poor coating surface properties, and variations in the coating film thickness. An image defect occurs.

  A more preferable range of the gap T between the air cap inner wall and the paint nozzle outer wall is 0.2 mm or more and 0.5 mm or less, and a particularly preferable range is 0.25 mm or more and 0.4 mm or less.

  Further, in addition to the positional relationship between the air cap 3 and the paint nozzle 2, the outer diameter D of the paint nozzle of the spray gun and the gap T between the inner wall of the air cap and the outer wall of the paint nozzle, as shown in FIG. The ratio (D / T) is preferably 0.1 to 1.0.

  By doing in this way, the coating liquid discharged from the coating nozzle discharge port 5 and the compressed air discharged from the air discharge port of the air cap are uniformly mixed, and the mist particle size can be equalized. Further, turbulence and stagnation are eliminated in the air flow in the vicinity of the paint nozzle discharge port 5, and adhesion of the coating liquid to the surfaces 7 and 8 adjacent to the paint nozzle discharge port 5 can be suppressed.

  A more preferable range of the ratio (D / T) between the outer diameter D and the gap T of the paint nozzle is 0.15 to 0.5.

  Further, in addition to the positional relationship between the air cap 3 and the paint nozzle 2 described above, as shown in FIG. 11, the outer surface (taper surface) roughness of the spray nozzle 2 of the spray gun and the surface roughness of the inner wall of the air cap are set to 1 It is preferable to set it to .6 s to 6.3 s or less.

  By smoothing the surface roughness in this way, there is no surface resistance when atomizing air is discharged, and atomized air is discharged smoothly, so that the mist particle size can be made uniform and the vicinity of the paint nozzle liquid discharge port can be achieved. It is possible to prevent the turbulent flow and the stagnation in the air flow and to prevent the coating liquid from adhering to the surfaces 7 and 8 adjacent to the paint nozzle discharge port 5.

  Next, a method for producing an electrophotographic photoreceptor produced by the electrophotographic photoreceptor production apparatus of the present invention will be described.

  As shown in FIG. 1, in an application booth 52, an object to be applied (workpiece in the figure) 51 is arranged to freely rotate and is sprayed by a spray gun 53 attached to a guide rail 54 so as to be movable in the axial direction of the work 51. The coating liquid is supplied from the coating liquid tank 58 and the atomizing air is supplied from the atomizing air tank 61, so that the coating liquid is atomized and sprayed onto the work 51.

  Here, the positional relationship and dimensions of the spray gun nozzle, the air cap, and the needle used in the method of manufacturing the electrophotographic photosensitive member are set in the above-described preferable range.

  That is, the difference (H) in the position between the tip of the air cap of the spray gun and the tip of the paint nozzle, the outer taper angle (θ) of the tip of the paint nozzle, the thickness (t) of the tip of the paint nozzle discharge port 5, the paint nozzle 2 Gap 9 where the needle 4 and the needle 4 are in contact with the outside air, the difference (h) between the position of the tip of the paint nozzle and the tip of the needle, chamfering of the corner 10 of the tip of the paint nozzle, each material of the paint nozzle, air cap, needle, The ratio (D / T) of the clearance T between the inner wall of the air cap and the outer wall of the coating nozzle, the outer diameter D of the coating nozzle and the clearance T between the inner wall of the air cap and the outer wall of the coating nozzle, the surface roughness of the outer diameter of the coating nozzle 2 and The air cap inner wall surface roughness is set within a suitable range.

  Moreover, it is preferable that the pressure of the compressed air (atomization air) which exits from the air cap air discharge port 1 is in the range of 20 KPa to 100 KPa, and the liquid discharge amount is in the range of 1 to 50 cc / min.

  By doing so, the balance between the atomized air and the coating liquid flow is optimized, and the mist particle size can be equalized.

  A more preferable range of the pressure of the compressed air (atomized air) and the liquid discharge amount is 25 to 50 KPa, and is 2.5 to 12 cc / min.

  As an example of the configuration of the electrophotographic photosensitive member, an undercoat layer, a charge generation layer, a charge transport layer, a protective layer, and the like are sequentially provided on a substrate (base).

  The object to be coated by the spray coating apparatus of the present invention is not limited to the electrophotographic photosensitive member as described above, but other than the electrophotographic photosensitive member, for example, coating by spray coating when manufacturing a transfer roller or a transfer belt. Film formation defects can also be suppressed in film formation and film formation by spray coating in the production of a fixing roller or a fixing belt, and a uniform and excellent quality coating film can be formed.

  In particular, it is suitable for spray coating of the above-mentioned components used in recent high-resolution electrophotographic apparatus of 1200 dpi or higher and electrophotographic apparatuses capable of full color output. For example, in the case of a fixing belt, a polyimide film belt is spray-coated with a primer, and a silicone resin is further coated thereon with a spray coating or the like. In addition, the present invention can be applied as it is.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to the Example shown below.

  (Example 1) Coating solutions for the undercoat layer, the charge generation layer, and the charge transport layer were prepared with the compositions shown below, and were respectively formed by electrospraying by spray coating under the following coating conditions. The body was made. Each layer was formed by continuous spray application of 10 layers, and 10 layers of the electrophotographic photosensitive member were produced by sequentially laminating each layer.

(Formation of undercoat layer) <Preparation of coating solution for undercoat layer>
15 parts by weight of alkyd resin (Beccosol 1307-60-EL (Dainippon Ink Chemical Co., Ltd.)) and 10 parts by weight of melamine resin (Super Becamine G-821-60 (Dainippon Ink Chemical Co., Ltd.)) It melt | dissolved in the weight part, 90 weight part of titanium oxide powders (Typer CR-EL (made by Ishihara Sangyo Co., Ltd.)) were added to this, and it disperse | distributed for 12 hours with the ball mill.
The obtained solution was taken out into a container and diluted with cyclohexanone so that the solid content was 25% by weight to obtain an undercoat layer coating solution.

<Coating conditions for coating solution for undercoat layer>
Using the spray coating apparatus shown in FIG. 1, the undercoat layer coating solution prepared above is spray coated onto a nickel seamless belt having a diameter of 170 mm, a length of 410 mm, a thickness of 30 μm, and a maximum surface roughness of 0.05 μm. A layer was formed.

  A spray gun having the structure shown in FIG. 12 was used.

  In addition, the names of the respective codes in FIG. 12, the angles or dimensions of the code parts, and other conditions are shown below.

  H: Difference in position between the tip of the air cap 3 and the tip of the paint nozzle discharge port 5 = the tip of the air cap 3 is +0.03 mm front. The measurement of H was performed using a dial gauge after assembling an air cap and a paint nozzle.

  θ: Taper angle of the tip of the paint nozzle 2 = 30 degrees

  t: Wall thickness at the tip of the coating nozzle discharge port 5 = 0.2 mm

  9 (c): the gap between the paint nozzle 2 and the needle 4 = 0.01 mm,

  h: Difference in position between the tip of the paint nozzle 2 and the tip of the needle = the tip of the needle protrudes 1.4 mm

  10 (m): chamfering the corner of the tip of the paint nozzle 2 = 0.1 mm

  Material: Paint nozzle = Trifluoroethylene chloride, Air cap 3 = Polypropylene, Needle tip = Cemented carbide

  T: Clearance between the inner wall of the air cap 3 and the outer wall of the paint nozzle = 0.35 mm

  T / D: Ratio of the tip outer diameter D of the paint nozzle 2 to the gap T between the air cap 3, the inner wall, and the outer wall of the paint nozzle 2 = 0.3

Spray gun atomizing air (compressed air) pressure = 25 KPa, liquid discharge amount = 6.0 cc / min. Outer diameter of paint nozzle 2 and surface roughness of inner wall of air cap 3 = 1.6 s

  For each measurement of θ, t, 9, h, 10, T, and T / D, a digital microscope having a shape measuring function (VHX200 manufactured by Keyence Corporation) was used. Further, the surface roughness was measured using a surface roughness meter (SE3500 manufactured by Kosaka Laboratory Ltd.). Due to the structure, the parts that could not be measured with a surface roughness meter were optimized at the manufacturing stage so that the surface roughness would not become rough.

  After spray coating under the above conditions, it was dried at 130 ° C. for 20 minutes to form an undercoat layer having a film thickness of 8.2 μm and a maximum film thickness difference of 0.4 μm in the effective image area.

(Formation of charge generation layer) <Preparation of coating solution for charge generation layer>
Next, 5 parts by weight of polyvinyl butyral resin (S-LEC HL-S: manufactured by Sekisui Chemical Co., Ltd.) is dissolved in 150 parts by weight of methyl ethyl ketone, and 10 parts by weight of a trisazo pigment represented by the following structural formula (1) is added thereto. After dispersion for 48 hours, 210 parts by weight of cyclohexanone was further added and dispersion was performed for 3 hours. The resulting solution was taken out into a container and diluted with cyclohexanone so that the solid content was 1.5% by weight.

<Coating conditions of coating solution for charge generation layer>
Using the spray gun of FIG. 12 as in the case of the undercoat layer, the charge generation layer coating solution prepared above was partially changed in the angle, dimensions and other conditions of the sign part of the spray gun as follows: It spray-coated on the to-be-coated object (work | work) in which the undercoat layer was formed. After coating, the film was dried at 130 ° C. for 20 minutes to form a charge generation layer having a transmittance of 4% at a wavelength of 690 nm and a maximum transmittance difference of 0.2% in the effective image area.

  H: Difference in position between the tip of the air cap 3 and the tip of the paint nozzle discharge port 5 = −0.25 mm at the tip of the air cap 3

  θ: Taper angle of the tip of the paint nozzle 2 = 30 degrees

  t: Wall thickness at the tip of the coating nozzle discharge port 5 = 0.2 mm

  9 (c): the gap between the paint nozzle 2 and the needle 4 = 0.01 mm,

  h: Difference in position between the tip of the paint nozzle 2 and the tip of the needle = the tip of the needle protrudes 1.4 mm

  10 (m): chamfering the corner of the tip of the paint nozzle 2 = 0.1 mm

  Material: Paint nozzle 2 = trifluoroethylene chloride, air cap 3 = polypropylene, needle tip = cemented carbide

  T: Clearance between the inner wall of the air cap 3 and the outer wall of the paint nozzle = 0.40 mm

    T / D: Ratio of the tip outer diameter D of the paint nozzle 2 to the gap T between the air cap 3, the inner wall, and the outer wall of the paint nozzle 2 = 0.25

  Spray gun atomizing air (compressed air) pressure = 50 KPa, liquid discharge rate = 3.0 cc / min

  The outer diameter of the paint nozzle 2 and the surface roughness of the inner wall of the air cap 3 = 1.6 s

(Formation of charge transport layer) <Preparation of coating solution for charge transport layer>
Next, bisphenol A type polycarbonate resin 10 and 0.002 part by weight of silicone oil (KF-50: manufactured by Shin-Etsu Chemical Co., Ltd.) are dissolved in 83 parts by weight of tetrahydrofuran, and a charge transport material of the following structural formula (2) is dissolved therein. 8 parts by weight was added and dissolved, and diluted with cyclohexanone so that the solid content was 8% by weight to prepare a charge transport layer coating solution.

<Coating conditions for coating solution for charge transport layer>
As in the case of the undercoat layer, the charge transport layer coating solution prepared above was partially changed in the angle, size and other conditions of the code part as follows using the spray gun of FIG. After spray coating on the top, it was dried at 130 ° C. for 20 minutes to form a charge transport layer having a thickness of 25 μm and a maximum thickness difference of 1.2 μm in the effective image area.

  H: Difference in position between the tip of the air cap 3 and the tip of the paint nozzle discharge port 5 = the air cap 3 is +0.3 mm

  θ: Taper angle of the tip of the paint nozzle 2 = 30 degrees

  t: Wall thickness at the tip of the coating nozzle discharge port 5 = 0.2 mm

  9 (c): the gap between the paint nozzle 2 and the needle 4 = 0.01 mm,

  h: Difference in position between the tip of the paint nozzle 2 and the tip of the needle = the tip of the needle protrudes 1.4 mm

  10 (m): chamfering the corner of the tip of the paint nozzle 2 = 0.1 mm

  Material: Paint nozzle 2 = SUS304, air cap 3 = polypropylene, needle tip = SUS304

  T: Clearance between the inner wall of the air cap 3 and the outer wall of the paint nozzle = 0.40 mm

  T / D: Ratio of the tip outer diameter D of the paint nozzle 2 to the gap T between the air cap 3, the inner wall, and the outer wall of the paint nozzle 2 = 0.25

  Atomizing air (compressed air) pressure of spray gun = 45 KPa, liquid discharge amount = 11.0 cc / min, outer diameter of paint nozzle 2 and surface roughness of inner wall of air cap 3 = 1.6 s

  Thereafter, both ends were cut so that the length of the endless belt-like photoconductor was 367 mm. 10 electrophotographic photoreceptors of Example 1 were produced as described above.

  The difference in film thickness between the undercoat layer and the charge transport layer obtained in Example 1 was obtained by providing a single film on the support in the same manner as in Example 1, and using an eddy current film thickness measuring instrument. The film thickness at 80 arbitrary measurement points was measured (manufactured by Fischer), and the difference between the maximum value and the minimum value was determined. The difference in the transmittance of the charge generation layer was similarly determined by providing a single film on the transparent PET film, measuring the transmittance at 690 nm by spectrophotometry at 60 arbitrary measurement points, and determining the difference between the maximum value and the minimum value. . The film thickness was measured in the same manner in the following examples and comparative examples.

(Example 2)
Although it is the same as that of Example 1, the angle of the code | symbol part of the spray gun shown in FIG. 12 in spray coating of a subbing layer, a charge generation layer, and a charge transport layer, a dimension, and other conditions were changed as follows. .

  H: Difference in position between the tip of the air cap 3 and the tip of the paint nozzle discharge port 5 = the air cap 3 is −0.01 mm

  θ: Taper angle of the tip of the paint nozzle 2 = 25 degrees

  t: Wall thickness at the tip of the paint nozzle discharge port 5 = 0.1 mm

  9 (c): the gap between the paint nozzle 2 and the needle 4 = 0.01 mm,

  h: Difference in position between the tip of the paint nozzle 2 and the tip of the needle = the tip of the needle protrudes 1.5 mm

  10 (m): chamfering the corner of the tip of the paint nozzle 2 = 0.05 mm

  Material: Paint nozzle 2 = SUS316, air cap 3 = PEEK, needle tip = SUS304

  T: Clearance between the inner wall of the air cap 3 and the outer wall of the paint nozzle = 0.40 mm

  T / D: Ratio of the tip outer diameter D of the paint nozzle 2 to the gap T between the air cap 3, the inner wall, and the outer wall of the paint nozzle 2 = 0.25

  Spray gun atomization air (compressed air) pressure = undercoat layer 20 KPa, charge generation layer 80 KPa, charge transport layer 50 KPa, liquid discharge amount = undercoat layer 7.0 cc / min, charge generation layer 2.5 cc / min, charge Transport layer 14 cc / min, outer diameter of paint nozzle 2 and surface roughness of inner wall of air cap 3 = 6.3 s

  The film thickness of the undercoat layer was 8.3 μm, and the maximum film thickness difference in the effective image area was 0.4 μm.

  Further, when the amount of the charge transport layer attached was expressed by a transmittance at a wavelength of 690 nm, the transmittance was 4% and the maximum transmittance difference in the effective image area was 0.5%.

  The thickness of the charge transport layer was 25 μm, and the maximum film thickness difference of the effective image area was 1.1 μm.

  Ten electrophotographic photoreceptors of Example 2 were produced as described above.

(Example 3)
Although it is the same as that of Example 1, the angle of the code | symbol part of the spray gun shown in FIG. 12 in the spray coating of an undercoat layer, a dimension, and other conditions were changed as follows.

  H: Difference in position between the tip of the air cap 3 and the tip of the paint nozzle discharge port 5 = -0.3 mm for the air cap 3

  θ: Taper angle of the tip of the paint nozzle 2 = 30 degrees

  t: Wall thickness at the tip of the coating nozzle discharge port 5 = 0.2 mm

  9 (c): the gap between the paint nozzle 2 and the needle 4 = 0.01 mm,

  h: Difference in position between the tip of the paint nozzle 2 and the tip of the needle = the tip of the needle protrudes 1.4 mm

  10 (m): chamfering the corner of the tip of the paint nozzle 2 = 0.1 mm

  Material: Paint nozzle 2 = trifluoroethylene chloride, air cap 3 = polypropylene, needle tip = cemented carbide

  T: Clearance between the inner wall of the air cap 3 and the outer wall of the paint nozzle = 0.35 mm

  T / D: Ratio of the tip outer diameter D of the paint nozzle 2 to the gap T between the air cap 3, the inner wall, and the outer wall of the paint nozzle 2 = 0.3

  Atomizing air (compressed air) pressure of spray gun = 25 KPa, liquid discharge amount = 5.5 cc / min, outer diameter of paint nozzle 2 and surface roughness of inner wall of air cap 3 = 1.6 s

  The film thickness of the undercoat layer was 6.3 μm, and the maximum film thickness difference in the effective image area was 0.3 μm.

  Further, when the amount of the charge transport layer attached was expressed by a transmittance at a wavelength of 690 nm, the transmittance was 4% and the maximum transmittance difference in the effective image area was 0.5%.

The film thickness of the charge transport layer was 25 μm, and the maximum film thickness difference in the effective image area was 1.0 μm.
10 electrophotographic photoreceptors of Example 3 were produced as described above.

(Comparative Example 1)
Although it is the same as that of Example 1, the angle of the code | symbol part of the spray gun shown in FIG. 12 in spray coating of a subbing layer, a charge generation layer, and a charge transport layer, a dimension, and other conditions were changed as follows. .

  H: Difference in position between the tip of the air cap 3 and the tip of the paint nozzle discharge port 5 = the air cap 3 is +0.5 mm

  θ: Taper angle of the tip of the paint nozzle 2 = 90 degrees

  t: Wall thickness at the tip of the paint nozzle outlet 5 = 1.0 mm

  9 (c): the gap between the paint nozzle 2 and the needle 4 = 0.5 mm,

  h: Difference in position between the tip of the paint nozzle 2 and the tip of the needle = the tip of the needle protrudes 0.5 mm

  Material: Paint nozzle 2 = SUS316, Air cap 3 = Brass chrome plating, Needle tip = SUS304

  T: Clearance between the inner wall of the air cap 3 and the outer wall of the paint nozzle = 0.35 mm

  T / D: Ratio of the tip outer diameter D of the paint nozzle 2 to the gap T between the air cap 3, the inner wall, and the outer wall of the paint nozzle 2 = 0.3

  The film thickness of the undercoat layer was 8.3 μm, and the maximum film thickness difference in the effective image area was 0.7 μm.

  Further, when the amount of the charge transport layer attached was indicated by the transmittance at a wavelength of 690 nm, the transmittance was 4% and the maximum transmittance difference in the effective image area was 0.9%.

The thickness of the charge transport layer was 25 μm, and the maximum film thickness difference in the effective image area was 1.4 μm.
10 electrophotographic photoreceptors of Example 3 were produced as described above.

(Comparative Example 2)
Although it is the same as that of Example 1, the angle of the code | symbol part of the spray gun in the spray coating of an undercoat layer, a charge generation layer, and a charge transport layer, a dimension, and other conditions were changed as follows.

  H: Difference in position between the tip of the air cap 3 and the tip of the paint nozzle discharge port 5 = 0.5 mm The paint nozzle retracts

  θ: Taper angle of the tip of the paint nozzle 2 = 90 degrees

  t: thickness of the coating nozzle discharge port 5 tip = 0.8 mm

  9 (c): the gap between the paint nozzle 2 and the needle 4 = 0.5 mm,

  h: Difference in position between the tip of the paint nozzle 2 and the tip of the needle = the needle tip retracts 0.5 mm

  Material: Paint nozzle 2 = SUS316, Air cap 3 = Brass chrome plating, Needle tip = SUS304

  The film thickness of the undercoat layer was 8.3 μm, and the maximum film thickness difference in the effective image area was 0.7 μm.

  Further, when the amount of the charge transport layer attached was indicated by the transmittance at a wavelength of 690 nm, the transmittance was 4% and the maximum transmittance difference in the effective image area was 0.9%.

  The thickness of the charge transport layer was 25 μm, and the maximum film thickness difference in the effective image area was 1.4 μm.

  10 electrophotographic photoreceptors of Example 3 were produced as described above.

(Evaluation of Comparative Examples and Examples) The electrophotographic photosensitive members of Examples 1 to 3 and Comparative Examples 1 and 2 obtained as described above were modified from Ricoh Co., Ltd. full color laser printer IPSIO Color 5000 (λ = 655 nm). The image was formed using 1200 dpi, modified to a beam spot of 2.7 × 10 ⁻³ mm ² , and the image quality was visually determined. The halftone image is a 2 × 2 dot image. Table 1 shows the image evaluation results.

  As can be seen from Table 1, in the examples of the present invention, no abnormality occurred in all the photoreceptors, and the effects of the present invention could be confirmed.

It is a schematic block diagram of the spray coating apparatus for components of the electrophotographic apparatus in the present invention. It is a schematic sectional drawing which shows the structural example of the spray gun in a spray coating device. It is a principal part enlarged view of the spray gun front end for demonstrating the preferable range of the position difference (H) of the front-end | tip of an air cap and the front-end | tip of a coating material nozzle in this invention. It is a principal part enlarged view of the spray gun front-end | tip for demonstrating the preferable range of the outer side taper angle ((theta)) of the coating-material nozzle front-end | tip part in this invention. It is an enlarged view of the paint nozzle discharge port for demonstrating the preferable range of the thickness (t) of the paint nozzle discharge port in this invention. It is a principal part enlarged view of the spray gun front end for demonstrating the preferable range of the clearance gap (c) which the coating-material nozzle needle in this invention contacts external air. It is a principal part enlarged view of the spray gun front end for demonstrating the preferable range of the difference (h) of the position of the paint nozzle front-end | tip and needle front-end | tip in this invention. It is a principal part enlarged view of the spray gun front end for demonstrating the preferable range of the removal width | variety (m) of the corner | angular part (cavity) of the coating-material nozzle tip in this invention. It is a principal part enlarged view of the spray gun front end for demonstrating the preferable range of the clearance gap T between the inner wall of the air cap in this invention, and the coating material nozzle outer wall. It is a principal part enlarged view of the spray gun front end for demonstrating the preferable range of ratio (D / T) of the outer diameter D of the coating material nozzle in this invention, and the clearance gap T of an air cap inner wall and a coating material nozzle outer wall. It is a principal part enlarged view of the tip of the spray gun for demonstrating the surface roughness of the coating nozzle outer diameter in this invention, and the surface roughness of an air cap inner wall. It is principal part sectional drawing for demonstrating the dimension and angle of each part of the spray gun used by the Example and the comparative example. It is sectional drawing of the conventional common spray gun.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Spray gun 2 Paint nozzle 3 Air cap 4 Needle 5 Paint nozzle discharge port 6 Discharge port 7 Surface adjacent to the paint nozzle discharge port 8 Surface adjacent to the paint nozzle discharge port 9 Gap between the paint nozzle and the needle in contact with the outside air 10 Paint Chamfered portion of nozzle tip corner 20 Flow path 30 Air feed path 40 Spray gun body H Difference in position between tip of air cap and tip of paint nozzle h Difference in position of tip of paint nozzle and tip of needle θ Outer taper angle of tip of paint nozzle T Clearance between paint nozzle and air cap D Paint nozzle outer diameter c Clearance indicated by c 9 chamfer width

Claims (4)

An electron that forms a coating film on the coating object by spraying a coating liquid from a spray gun attached to a guide rail so as to be movable in the axial direction of the coating object while rotating the coating object in a coating booth. A spray coating device for parts of a photographic apparatus,
The spray gun includes a coating nozzle and an air cap configured to feed the coating liquid and atomizing air, respectively, and a needle in the coating nozzle.
The paint nozzle has a flow path and a discharge port for feeding a coating liquid, and an air feed path and a discharge port for feeding atomized air between the air cap and the paint nozzle,
Furthermore, the spray coating apparatus for parts of an electrophotographic apparatus is characterized in that either the front end of the air cap and the front end of the paint nozzle are front surfaces with a difference of ± 0.3 mm.   The outer taper angle (θ) of the nozzle tip of the spray gun is in the range of 15 to 45 degrees, and the wall thickness (t) of the nozzle outlet of the spray gun is 0.1 mm or more and 0.5 mm or less. A gap (c) where the paint nozzle of the spray gun and the needle are in contact with the outside air is 0.1 mm or less, a needle tip of the spray gun is projected from 0.1 mm to 2 mm from the tip of the paint nozzle, the spray Chamfer the corner of the gun's paint nozzle tip, the spray gun's paint nozzle discharge port, air cap, needle tip material, respectively, trifluoroethylene chloride, polypropylene, cemented carbide, or SUS, SUS, respectively. PEEK, the clearance (T) between the inner wall of the spray gun air cap and the outer wall of the paint nozzle is 0.15 m. The ratio (D / T) between the outer diameter D of the paint nozzle of the spray gun and the gap T between the inner wall of the air cap and the outer wall of the paint nozzle is 0.1 to 1.0. 2. The electron according to claim 1, further comprising at least one of setting the surface roughness of the wall surface of the paint nozzle of the spray gun and the inner wall of the air cap to 1.6 to 6.3 S. Spray applicator for photographic equipment parts.   A spray coating apparatus for parts of an electrophotographic apparatus according to claim 1 or 2, wherein a coating liquid is fed and discharged from a flow path and a discharge port of the paint nozzle, and the air cap and the paint nozzle A method for producing an electrophotographic photosensitive member, characterized in that atomized air is fed and discharged from a gap between the gap and a discharge port, and the coating solution is sprayed and applied onto a substrate.   4. The method for producing an electrophotographic photosensitive member according to claim 3, wherein the pressure of the atomizing air of the spray gun is 20 to 100 KPa, and the liquid discharge amount is 1 to 50 cc / min.

Images