JP2007127922A - Electrophotographic photoreceptor manufacturing device and manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a uniform coating performance by preventing stagnation of flow in a coating bath when carrying out coating of a multiplicity of base substances in a monobath coating bath simultaneously, increasing the displacement efficiency of a coating liquid, and preventing an increase in the viscosity of the coating liquid. <P>SOLUTION: The present invention is an electrophotographic photoreceptor manufacturing device having a monobath coating bath in which a coating liquid is cast into the coating bath from below by a solution sending device from a coating liquid stock tank 1 and is made to overflow the upper end for controlling the liquid level, and a multiplicity of bases substances of electrophotographic photoreceptors are immersed simultaneously for coating. The monobath coating bath comprises a straight pipe part 9 disposed in the same arrangement for each individual base substance of the photoreceptor, an assembly part 11, and one or more tapered inflow fluid diffusion part 6, and two or more straightening plates 3 are provided to each of the tapered inflow fluid diffusion part 6. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an electrophotographic photoreceptor manufacturing apparatus and a manufacturing method.

In the application of the electrophotographic photosensitive member, a dip coating method is used for mass production at a time.
As a problem of the dipping method, when the thixotropic coating solution is circulated, stagnation of the coating solution having a locally increased viscosity may occur in the coating tank. For this reason, it is necessary to control the flow of the coating liquid so that the liquid does not stagnate.
If production is continued with stagnation occurring, the coating solution whose viscosity has increased during dip coating of the cylindrical substrate adheres to the surface of the substrate, resulting in coating thickness unevenness. A fatal problem arises.
Also, if the production is stopped and the inside is stirred to remove the stagnation in the coating tank, there will be a problem of lowering the productivity, or even if an impeller for stirring is installed in the coating tank, the impeller slides. There is a possibility that the inside of the tank becomes a turbulent flow due to the generation of foreign matter from the part and the impeller, thereby causing other defects such as flow unevenness on the substrate.
When a thixotropic coating solution is used, the properties of the solution, if left standing, solidifies into a gel and rises in viscosity. When it is shaken, it changes into a sol only while it moves, and fluidity appears. For this reason, the local increase in viscosity occurs when the inside of the coating tank is not rectified and there is almost no flow of the liquid, and there is a stagnation part of the flow that becomes a vortex.

  In addition, in order to produce a high-sensitivity and high-resolution photoreceptor that has been preferred in recent years, a uniform coating thickness is required, and improvement of stagnation in the coating tank is regarded as important. This is a problem particularly when a so-called CGL layer is applied.

Conventionally, there has been a proposal for a technique for producing an electrophotographic photoreceptor having excellent characteristics by using a production apparatus that has a rectifying layer in which spherical objects are gathered, rectifies the flow in the coating tank, and has a uniform film. (For example, refer to Patent Document 1).
In this case, the flow of the coating liquid cannot be generated in the entire rectifying layer, the coating liquid easily flows in the center, and the flow speed of the coating liquid is reduced between the spherical objects on the wall surface side, so that the thixotropic coating liquid is used. When it circulates, the viscosity of the coating liquid increases in the gap between the spherical objects on the wall surface side. As a result, there is a problem in that when the coating liquid with increased viscosity adheres to the cylindrical substrate, it becomes uneven density and causes image defects.

Conventionally, a technique for controlling the flow velocity in the tank by providing a current plate has also been proposed (see, for example, Patent Documents 2 to 4). However, in this technique, the current plate is tapered. It is said that it is sufficient to install one piece at the top of the department.
However, in actuality, when the thixotropic coating liquid is circulated, a stagnation point occurs in the tapered portion below the current plate, and the viscosity of the coating liquid increases. When it adheres to the substrate, it becomes uneven in density, resulting in an image defect.

  Further, conventionally, as a method of controlling the flow near the lower part of the coating object in the direction of the coating tank wall surface when immersing the coating object, an inverted conical float is floated on the coating liquid surface, There is also a proposal for a technique for preventing unevenness of density in dip coating using a thixotropic coating solution by immersing the coating material together to create a flow (for example, Patent Document 5). To increase production efficiency, so that the viscosity of the coating solution is lowered, soaked, and when the pulling speed is increased, the gap between the float and the inner wall of the coating tank is narrow. There is a problem that uneven density occurs. This technique redistributes the stagnation that has occurred and is not a technique that does not fundamentally generate stagnation.

Conventionally, some pigment-dispersed coating solutions have a thixotropic property in which the viscosity changes when a force such as a flow is applied. If the thixotropic coating solution is circulated in the coating tank, If the flow rate of the coating liquid is slow and a stagnation part that becomes a vortex occurs, the viscosity of the coating liquid in the stagnation part increases.
When the cylindrical substrate is dipped and pulled up, and the coating solution with increased viscosity adheres to the cylindrical substrate during the formation of the coating film, the density becomes uneven and image defects occur.

  Conventionally, there has been proposed a technique for performing rectification above the rectification mechanism in the coating tank with a single rectifying plate or a rectifying layer using a spherical object. The flow rate of the coating liquid is slow and a stagnation part that becomes a vortex is generated in the gap between the tapered portion below the rectifying plate diffusing into the diameter and the spherical object on the side of the tapered portion wall surface. When a thixotropic coating solution is circulated with this technology, the viscosity of the stagnation part increases with time after circulation, and the coating solution viscosity in the coating tank becomes non-uniform, and this coating solution adheres to the circumferential substrate. By doing so, it became uneven gray.

JP-A-8-320580 JP-A-6-254459 Japanese Patent Laid-Open No. 10-43652 JP 2002-49162 A Japanese Patent Laid-Open No. 10-48849

  Therefore, in the present invention, in view of the above-mentioned problems of the prior art, when a coating film is formed by immersing and pulling a large number of pieces into a coating bath having a single bath structure, stagnation occurs in the flow in the coating bath. By adopting a coating tank structure that does not, the flow in the tank is rectified, the occurrence of stagnation is suppressed to increase the replacement efficiency of the coating liquid, and the increase in the viscosity of the coating liquid is prevented.

  In the present invention, the coating liquid is supplied from the coating liquid stock tank from the lower side of the coating tank by the liquid feeding device and overflowed from the upper end to control the liquid surface height, and a large number of electrophotographic photosensitive member substrates are immersed simultaneously. An electrophotographic photoreceptor manufacturing apparatus having a coating bath having a one-bath structure that can be applied, and the one-bath structure coating tank includes straight pipe portions provided in the same array for each photosensitive substrate. An electrophotographic photoreceptor manufacturing apparatus having a configuration in which a collecting section and one or more tapered inflow liquid diffusion sections are provided, and each of the tapered inflow liquid diffusion sections is provided with two rectifying plates. provide.

  According to a second aspect of the present invention, at least one of the tapered inflowing liquid diffusion portions is divided at intervals of 200 mm or less, and one or more of the tapered influent diffusion portions are arranged. A photoreceptor manufacturing apparatus is provided.

  According to a third aspect of the present invention, in the tape-like influent diffusion portion, one side of the gathering portion is divided every 150 mm or less, and one or more electrophotographic photosensitive members are arranged. A body manufacturing apparatus is provided.

  In the invention of claim 4, two of the current plate are disposed below the lowermost position of the immersion so as not to interfere with the electrophotographic photoreceptor substrate during dip coating, One of the sheets installed at the top of the tapered inflow liquid diffusion part has an inner diameter that is approximately the same as the inner diameter of the collecting part, and one sheet installed at the bottom of the one is below the tapered inflow liquid diffusion part. The electrophotographic photosensitive member manufacturing apparatus according to claim 1, wherein the inner diameter is approximately the same as the inner diameter of the coating liquid inflow pipe.

  According to a fifth aspect of the present invention, there is provided the electrophotographic photosensitive member manufacturing apparatus according to the first aspect, wherein the rectifying plate is a perforated plate.

  According to a sixth aspect of the present invention, there is provided the electrophotographic photoreceptor manufacturing apparatus according to the fifth aspect, wherein the aperture ratio of the perforated plate is in the range of 30% to 60%.

  According to a seventh aspect of the present invention, there is provided the electrophotographic photosensitive member manufacturing apparatus according to the fifth aspect, wherein the hole diameter of the perforated plate is in a range of φ0.5 mm or more and φ5 mm or less.

  According to an eighth aspect of the present invention, there is provided the electrophotographic photosensitive member manufacturing apparatus according to the first aspect, wherein a taper angle of the tapered influent diffusion portion is 45 degrees or less.

  According to a ninth aspect of the present invention, there is provided the electrophotographic photosensitive member manufacturing apparatus according to the first aspect, wherein a cross-shaped partition plate is provided inside the tapered inflowing liquid diffusion portion.

  According to a tenth aspect of the present invention, in the electrophotographic photosensitive member according to the first aspect, an inner diameter of the straight tube portions provided in the same arrangement for each of the photosensitive substrate is at least 14 mm from the outer shape of the photosensitive substrate. A body manufacturing apparatus is provided.

  According to an eleventh aspect of the present invention, the inner diameter of the straight tube portions provided in the same arrangement for each of the photosensitive substrate is 30 mm or more from the outer shape of the photosensitive substrate. Providing manufacturing equipment.

  According to a twelfth aspect of the present invention, the height of the straight pipe portions provided in the same arrangement for each of the photosensitive substrate is at least equal to or higher than the height of the outer shape of the photosensitive substrate. Provided is a photographic photoreceptor manufacturing apparatus.

  According to a thirteenth aspect of the present invention, the height of the straight tube portions provided in the same arrangement for each of the photosensitive substrate is at least twice the outer shape of the photosensitive substrate. A photoreceptor manufacturing apparatus is provided.

  According to a fourteenth aspect of the present invention, there is provided a method for producing an electrophotographic photosensitive member, wherein the electrophotographic photosensitive member is produced in the coating tank according to any one of the first to thirteenth aspects.

  According to a fifteenth aspect of the present invention, there is provided an electrophotographic photosensitive member that is coated by the electrophotographic photosensitive member manufacturing apparatus according to any one of the first to thirteenth aspects.

  According to a sixteenth aspect of the present invention, there is provided the electrophotographic photosensitive member according to the fifteenth aspect, wherein the photosensitive layer is an electrophotographic photosensitive member having a laminated structure of a charge generation layer and a charge transport layer.

With the electrophotographic photoreceptor manufacturing apparatus of the present invention, the flow in the coating tank is rectified and the occurrence of stagnation is suppressed, thereby increasing the replacement efficiency of the coating liquid and preventing the increase in the viscosity of the coating liquid. .
In addition, according to the electrophotographic photoconductor manufacturing apparatus according to any one of claims 10 to 13, the flow overflowing from the coating tank can be controlled individually for each photoconductor substrate, and a high-quality coating is performed. A film could be formed.
In addition, by the electrophotographic photoreceptor manufacturing method according to claim 14, an electrophotographic photoreceptor having a uniform coating film without unevenness in density is manufactured by dip coating in a coating tank in which no increase in viscosity occurs. I was able to do that.
In addition, according to the inventions of claims 15 and 16, a high-quality image can be obtained by an electrophotographic photosensitive member formed with a uniform coating film having no uneven density.

  That is, in the present invention, by providing two rectifying plates, more preferably, by defining the number of tapered inflow liquid diffusion portions, angle, rectifying plate shape (opening ratio, hole diameter), cross-shaped partition plate, The coating liquid flows from the coating liquid inflow pipe, diffuses into the inner diameter of the coating tank, and rectifies the flow in the tank that overflows to suppress the occurrence of stagnation, thereby increasing the replacement efficiency of the coating liquid and preventing the viscosity of the coating liquid from increasing. It has become possible. Therefore, an electrophotographic photosensitive member formed with a uniform coating film with no uneven density could be produced.

  In addition, the present invention aims to prevent uneven density increase in viscosity with a thixotropic coating liquid, but in order to prevent increase in viscosity, the flow in the coating tank is rectified and the replacement efficiency is improved. Therefore, it is confirmed that the dispersible liquid is prevented from settling, foreign matter stays in the tank, and the temperature of the coating liquid is stabilized, and can be used for Newtonian liquids.

  Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to the following examples.

First, as a specific example of the invention of claim 1, FIG. 1 shows a schematic view of an electrophotographic photoreceptor manufacturing apparatus.
In this apparatus, a coating liquid is caused to flow from below the coating tank 4 by a liquid feeding device 2 such as a pump from the coating liquid stock tank 1, and the liquid level is controlled by overflowing from the upper end. It has a coating bath 4 having a one-bath structure for immersing and coating a large number of body substrates at the same time.
The coating bath 4 having a one-bath structure is provided with a straight pipe portion 9 provided in the same arrangement for each photoreceptor substrate, a collecting portion 11 and one or more tapered inflowing liquid diffusion portions 6. Each tapered inflow liquid diffusing portion 6 is provided with two or more rectifying plates 3, thereby rectifying the flow in the tank.
The rectifying plate 3 is detachably disposed at a predetermined position of the tapered inflowing liquid diffusion portion 6 of the coating tank. For example, each time a coating liquid having a different viscosity is applied, a rectifying plate having a different opening ratio and hole diameter is used. It can be replaced.

FIG. 2 shows a schematic plan view of a specific essential part of the current plate 3. However, the rectifying plate 3 is not limited to the structure shown in FIG.
Installation location: Two pieces on the upper side and lower side of the tapered inflow liquid diffusion part of FIG. 1 Hole diameter of the rectifying plate 3: φ2 mm
Hole arrangement pitch: 3 degree 60 degree staggered arrangement

As a utilization range of this apparatus, it is preferable that a coating liquid is about 1 mPa * s-800 mPa * s on the process of forming a coating film by dip coating.
The average flow velocity in the tank is preferably 0.003 m / s to 0.02 m / s.

Next, an electrophotographic photosensitive member manufactured by the apparatus shown in FIG. 1 will be described.
[Support]
Examples of the conductive support constituting the electrophotographic photoreceptor include those having a volume resistance of 1010 Ω · cm or less, for example, metals such as aluminum, nickel, chromium, nichrome, copper, gold, silver, and platinum, tin oxide , Metal oxides such as indium oxide by vapor deposition or sputtering, film or cylindrical plastic, paper coated, or aluminum, aluminum alloy, nickel, stainless steel plates, etc., and extruding them After forming the tube by a method such as the above, it is possible to use a tube subjected to surface treatment such as cutting, superfinishing or polishing.
Further, endless nickel belts and endless stainless steel belts disclosed in JP-A-52-36016 can also be applied as the conductive support.
In addition, those obtained by dispersing and coating conductive powder in an appropriate binder resin on the support can also be applied as a conductive support.

(Photosensitive layer)
The photosensitive layer may be either a single layer type or a laminated type. First, the charge generation layer will be described.
The charge generation layer is a layer mainly composed of a charge generation material, and a binder resin is used as necessary.
As the charge generation material, inorganic materials and organic materials can be applied.
Examples of inorganic materials include crystalline selenium, amorphous selenium, selenium-tellurium, selenium-tellurium-halogen, and selenium-arsenic compounds.
On the other hand, as the organic material, known materials can be applied. For example, phthalocyanine pigments such as metal phthalocyanine and metal-free phthalocyanine, azulenium salt pigments, squalic acid methine pigments, azo pigments having a carbazole skeleton, triphenylamine skeleton Azo pigments having a diphenylamine skeleton, azo pigments having a dibenzothiophene skeleton, azo pigments having a fluorenone skeleton, azo pigments having an oxadiazole skeleton, azo pigments having a bis-stilbene skeleton, distyryl oxadiazole skeleton Azo pigments having a distyrylcarbazole skeleton, perylene pigments, anthraquinone or polycyclic quinone pigments, quinoneimine pigments, diphenylmethane and triphenylmethane pigments, benzoquinone and naphtho Non pigments, cyanine and azomethine pigments, indigoid pigments, bisbenzimidazole pigments.
These charge generation materials may be used alone or as a mixture of two or more.

The photosensitive layer of the photoreceptor may be a single layer structure or a stacked structure. First, the case of a stacked structure including a charge generation layer and a charge transport layer will be described.
The charge generation layer is a layer mainly composed of a charge generation material.
Known charge generation materials can be applied to the charge generation layer, such as monoazo pigments, disazo pigments, trisazo pigments, perylene pigments, perinone pigments, quinacridone pigments, quinone condensed polycyclic compounds, squalic acid dyes, Other phthalocyanine pigments, naphthalocyanine pigments, azurenium salt dyes and the like are used.
These charge generation materials may be used alone or in combination of two or more.

For the charge generation layer, the charge generation material is dispersed in a suitable solvent together with a binder resin as necessary using a ball mill, attritor, sand mill, ultrasonic wave, etc., and this is applied onto a conductive support and dried. It is formed by doing.
As the binder resin, polyamide, polyurethane, epoxy resin, polyketone, polycarbonate, silicone resin, acrylic resin, polyvinyl butyral, polyvinyl formal, polyvinyl ketone, polystyrene, polysulfone, poly-N-vinylcarbazole, polyacrylamide, polyvinyl benzal, Examples include polyester, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, polyphenylene oxide, polyamide, polyvinyl pyridine, cellulose resin, casein, polyvinyl alcohol, and polyvinyl pyrrolidone.
The amount of the binder resin is 0 to 500 parts by weight, preferably 10 to 300 parts by weight with respect to 100 parts by weight of the charge generation material.

The binder resin may be added before dispersion or after dispersion.
Examples of applicable solvents include isopropanol, acetone, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethyl cellosolve, ethyl acetate, methyl acetate, dichloromethane, dichloroethane, monochlorobenzene, cyclohexane, toluene, xylene, ligroin and the like. In particular, ketone solvents, ester solvents, and ether solvents are preferred. These may be used alone or in combination of two or more.

The charge generation layer is mainly composed of a charge generation material, a solvent, and a binder resin, but may contain a sensitizer, a dispersant, a surfactant, silicone oil, and the like.
As the coating method of the coating solution, methods such as dip coating, spray coating, beat coating, nozzle coating, spinner coating, ring coating and the like can be applied.
The film thickness of the charge generation layer is suitably about 0.01 to 5 μm, preferably 0.1 to 2 μm.

The charge transport layer can be formed by dissolving or dispersing the charge transport material and the binder resin in an appropriate solvent, and applying and drying the solution on the charge generation layer.
Moreover, you may add individually or 2 or more types of plasticizers, leveling agents, etc. as needed.
Charge transport materials include hole transport materials and electron transport materials.
Examples of the electron transporting material include chloroanil, bromoanil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4 , 5,7-tetranitroxanthone, 2,4,8-trinitrothioxanthone, 2,6,8-trinitro-4H-indeno [1,2-b] thiophen-4-one, 1,3,7-tri Examples thereof include electron-accepting substances such as nitrodibenzothiophene-5,5-dioxide and benzoquinone derivatives.
Examples of hole transport materials include poly-N-vinylcarbazole and derivatives thereof, poly-γ-carbazolylethyl glutamate and derivatives thereof, pyrene-formaldehyde condensates and derivatives thereof, polyvinylpyrene, polyvinylphenanthrene, polysilane, oxazole derivatives, Oxadiazole derivatives, imidazole derivatives, monoarylamine derivatives, diarylamine derivatives, triarylamine derivatives, stilbene derivatives, α-phenylstilbene derivatives, benzidine derivatives, diarylmethane derivatives, triarylmethane derivatives, 9-styrylanthracene derivatives, pyrazolines Derivatives, divinylbenzene derivatives, hydrazone derivatives, indene derivatives, butadiene derivatives, pyrene derivatives, bisstilbene derivatives, enamine derivatives, etc. Other known materials may be used. These charge transport materials may be used alone or in combination of two or more.

Examples of the binder resin include polystyrene, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyester, polyvinyl chloride, vinyl chloride-vinyl acetate copolymer, polyvinyl acetate, Polyvinylidene chloride, polyarylate resin, phenoxy resin, polycarbonate, cellulose acetate resin, ethyl cellulose resin, polyvinyl butyral, polyvinyl formal, polyvinyl toluene, poly-N-vinyl carbazole, acrylic resin, silicone resin, epoxy resin, melamine resin, urethane resin And thermoplastic or thermosetting resins such as phenol resins and alkyd resins.
The amount of the charge transport material is appropriately 20 to 300 parts by weight, preferably 40 to 150 parts by weight with respect to 100 parts by weight of the binder resin.
The thickness of the charge transport layer is preferably 25 μm or less from the viewpoint of resolution and responsiveness.
The lower limit varies depending on the system to be used (particularly charging potential), but is preferably 5 μm or more.

As the solvent, tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, acetone and the like can be applied. These may be used alone or in combination of two or more.
When the photosensitive layer has the laminated structure as described above, it is more preferable that the organic sulfur compound to be contained in the photosensitive layer is contained in the charge transport layer.

Next, the case where the photosensitive layer has a single layer structure will be described.
For the single photosensitive layer, the above-described charge generation materials, charge transport materials, binder resins and the like can be applied.
The photosensitive layer can be formed by dissolving or dispersing a charge generating substance, a charge transporting substance, the above-described sulfur-based compound, and a binder resin in a suitable solvent, and applying and drying them.
Moreover, a plasticizer, a leveling agent, etc. can also be added as needed.
The amount of the charge generation material with respect to 100 parts by weight of the binder resin is preferably 5 to 40 parts by weight, and the amount of the charge transport material is preferably 0 to 190 parts by weight, and more preferably 50 to 150 parts by weight.
The photosensitive layer is formed by dip coating, spray coating, bead coating, a coating solution in which a charge generating material and a binder resin are dispersed together with a charge transporting material using a solvent such as tetrahydrofuran, dioxane, dichloroethane, and cyclohexane. It can be formed by coating with a ring coat or the like.
The film thickness of the photosensitive layer is suitably about 5 to 25 μm.

Next, the protective layer will be described.
In the protective layer, the filler material is dispersed together with the binder resin through an appropriate solvent, and a compound having both a hindered amine structure and a hindered phenol structure is added and dissolved, and this is applied onto the photosensitive layer and dried. Is formed.
In order to suppress deterioration of the photoreceptor from active gases such as ozone by repeated use over a long period of time by using a compound having both a hindered amine structure and a hindered phenol structure in the protective layer that is the outermost layer of the photoreceptor, It is possible to dramatically improve not only the wear resistance but also the image stability.

  The ratio of the filler material and the compound having both the hindered amine structure and the hindered phenol structure is 0.01 wt% to 50 wt%, more preferably 0.1 wt% to 20 wt% with respect to the filler. When the addition amount is too large, the wear resistance is lowered. On the other hand, when the addition amount is too small, the abnormal image suppressing effect cannot be sufficiently exhibited.

Examples of the binder resin material used for the protective layer include ABS resin, ACS resin, olefin-vinyl monomer copolymer, chlorinated polyether, aryl resin, phenol resin, polyacetal, polyamide, polyamideimide, polyacrylate, Polyallylsulfone, polybutylene, polybutylene terephthalate, polycarbonate, polyethersulfone, polyethylene, polyethylene terephthalate, polyimide, acrylic resin, polymethylbenten, polypropylene, polyphenylene oxide, polysulfone, polystyrene, polyarylate, AS resin, butadiene-styrene copolymer Examples thereof include resins such as coalescence, polyurethane, polyvinyl chloride, polyvinylidene chloride, and epoxy resin.
From the viewpoint of filler dispersibility, residual potential, and coating film defects, polycarbonate or polyarylate is particularly effective and useful.

Fillers are generally classified into organic fillers and inorganic fillers.
Examples of the organic filler material include fluororesin powder such as polytetrafluoroethylene, silicone resin powder, a-carbon powder, and the like, and examples of the inorganic filler material include metals such as copper, tin, aluminum, and indium. Powder, silica, tin oxide, zinc oxide, titanium oxide, alumina, zirconium oxide, indium oxide, antimony oxide, bismuth oxide, calcium oxide, antimony-doped tin oxide, tin-doped metal oxides such as indium oxide, fluorine Examples thereof include metal fluorides such as tin fluoride, calcium fluoride, and aluminum fluoride, potassium titanate, boron nitride, and the like.
Among these fillers, the use of an inorganic pigment which is an inorganic filler is advantageous for improving the wear resistance from the viewpoint of the hardness of the filler.
Further, these fillers can be surface-treated with at least one kind of surface treatment agent, and it is preferable from the viewpoint of dispersibility of the fillers.
Lowering the dispersibility of the filler not only increases the residual potential, but also decreases the transparency of the coating film, causes defects in the coating film, and decreases the wear resistance. It can develop into a big problem to hinder.

As the surface treatment agent, a conventionally used surface treatment agent can be used, but a surface treatment agent capable of maintaining the insulating properties of the filler is preferable.
For example, titanate coupling agents, aluminum coupling agents, zircoaluminate coupling agents, higher fatty acids, etc., or mixed treatments of these with silane coupling agents, Al ₂ O ₃ , TiO ₂ , ZrO ₂ , Silicone, aluminum stearate, or the like, or a mixture thereof is more preferable from the viewpoint of filler dispersibility and image blur.
The treatment with the silane coupling agent is strongly influenced by image blur, but the influence may be suppressed by performing a mixing treatment of the surface treatment agent and the silane coupling agent. The surface treatment amount varies depending on the average primary particle size of the filler used, but is preferably 3 to 30 wt%, more preferably 5 to 20 wt%.
If the surface treatment amount is less than this, the filler dispersion effect cannot be obtained, and if it is too much, the residual potential is significantly increased.

As the solvent, any of the solvents used in the charge transport layer, such as tetrahydrofuran, dioxane, toluene, dichloromethane, monochlorobenzene, dichloroethane, cyclohexanone, methyl ethyl ketone, and acetone, can be applied.
However, a solvent having a high viscosity at the time of dispersion is preferable, but a solvent having a high volatility is preferable at the time of coating. When there is no solvent satisfying these conditions, it is possible to use a mixture of two or more solvents having respective physical properties, which may have a great effect on filler dispersibility and residual potential. .

In addition, the addition of the charge transport material mentioned in the charge transport layer to the protective layer is effective and useful for reducing the residual potential and improving the image quality. At this time, a charge transport material having an ionization potential (Ip) of the charge transport material contained in the protective layer equal to or smaller than (Ip) of the charge transport material contained in the photosensitive layer is used. By adding to, the charge injection property to the protective layer is improved, so that the residual potential can be further reduced.
Note that the ionization potential (Ip) can be measured using various methods such as a spectroscopic method and an electrochemical method.

  The filler material can be dispersed using a conventional method such as a ball mill, an attritor, a sand mill, or an ultrasonic wave. In particular, dispersion by a ball mill with less contamination from the outside is more preferable from the viewpoint of dispersibility.

As the material of the media used, any conventionally used media such as zirconia, alumina, and agate can be used.
Moreover, it is preferable from the point of the light transmittance of a protective layer, and the abrasion resistance that the average primary particle diameter of a filler is 0.01-0.5 micrometer.
When the average primary particle size of the filler is 0.01 μm or less, it causes a decrease in wear resistance, a decrease in dispersibility, etc., and when it is 0.5 μm or more, the settling property of the filler is promoted or the toner fills. May occur.

As a method for forming the protective layer, conventional methods such as dip coating, spray coating, beat coating, nozzle coating, spinner coating, ring coating, etc. can be used. desirable.
Furthermore, it is possible to form the protective layer by coating the required film thickness of the protective layer at one time, but it is more preferable to apply the coating two or more times to make the protective layer multi-layered. More preferable in terms of uniformity.
By doing so, a further effect can be obtained with respect to reduction of residual potential, improvement of resolution, and improvement of wear resistance. In addition, about 0.1-10 micrometers is suitable for the thickness of a protective layer.

An undercoat layer may be provided between the conductive support and the photosensitive layer.
The undercoat layer generally contains a resin as a main component. However, considering that the photosensitive layer formed as an upper layer of the resin is coated and formed using a solvent, the resin is resistant to general organic solvents. It is desirable for the resin to be high.
Examples of such resins include water-soluble resins such as polyvinyl alcohol, casein, and sodium polyacrylate, alcohol-soluble resins such as copolymer nylon and methoxymethylated nylon, polyurethane, melamine resin, phenol resin, and alkyd-melamine resin. And curable resins that form a three-dimensional network structure, such as epoxy resins.
Further, a metal oxide fine powder pigment exemplified by titanium oxide, silica, alumina, zirconium oxide, tin oxide, indium oxide and the like may be added to the undercoat layer in order to prevent moire and reduce residual potential.

These undercoat layers can be formed using an appropriate solvent and a coating method like the above-mentioned photosensitive layer.
Furthermore, a silane coupling agent, a titanium coupling agent, a chromium coupling agent, or the like can be used as the undercoat layer.
In addition, in the undercoat layer of the present invention, Al ₂ O ₃ is provided by anodic oxidation, organic substances such as polyparaxylylene (parylene), SiO ₂ , SnO ₂ , TiO ₂ , ITO, CeO ₂ A material provided with an inorganic material such as a vacuum thin film can also be used favorably.
In addition, known ones can be used.
The thickness of the undercoat layer is suitably from 0 to 5 μm.

Hereinafter, the present invention will be described with reference to specific examples, but the present invention is not limited to the following examples.
The undercoat layer, the charge generation layer, and the charge transport layer were sequentially dip coated, and the coating film was visually confirmed. In the charge generation layer coating step, a thixotropic coating solution was used and dip coating was performed after circulation for a predetermined time in the apparatus of the present invention or the conventional apparatus.
The composition of the coating solution for the charge generation layer used in the examples is shown below.

1. Formation of undercoat layer coating solution An undercoat layer coating solution was prepared by dispersing the following materials.
Melamine resin 5 parts by weight Titanium oxide 20 parts by weight Cyclohexanone 35 parts by weight Methyl ethyl ketone 35 parts by weight

2. Preparation of charge generation layer coating solution Disazo pigment 1 part by weight Polyvinyl butyral 0.5 part by weight Cyclohexanone 40 parts by weight Methyl ethyl ketone 60 parts by weight After ball mill dispersion, cyclohexanone and methyl ethyl ketone were added to obtain a charge generation layer coating liquid.

3. Preparation of coating solution for charge transport layer 4 parts by weight of charge transport agent represented by the following formula (1)

Polycarbonate 6 parts by weight Cyclohexanone 45 parts by weight Tetrahydrofuran 45 parts by weight Silicon oil 0.001 part by weight was dissolved to prepare a charge transport layer coating solution.

  The undercoating layer (UL) coating solution prepared above is applied to an aluminum cylindrical substrate having an outer diameter of 30 mm and a length of 340 mm, and dried at 110 ° C. for 15 minutes to form an undercoating layer having a thickness of 5 μm. did.

Next, a charge generation layer (CGL) and a charge transport layer (CTL) were applied and dried thereon to produce a laminated photoreceptor sample.
The charge generation layer was formed under the condition that the dry film thickness was 0.2 μm and the charge transport layer was 23 μm.
The thixotropic pigment-dispersed coating liquid used was 3.5 mPa · s.
In the examples, the average flow velocity in the straight pipe portion was 0.008 m / s.

<Apparatus conditions for Examples and Comparative Examples>
[Example 1]
Two porous rectifying plates 3 having a diameter of 2 mm and an open efficiency of 40% were installed above and below the tapered portion 6.
Regarding the “number” related to the inventions described in claims 2 and 3, since the outer shape of the collective portion 11 is 471 mm × 246 mm, the 471 mm side is divided into 3 parts and the 246 mm side is divided into 2 parts, and 6 pieces are arranged. .
With respect to the “taper angle” relating to the invention described in claim 8, the height was set to 200 mm so as to be about 30 degrees, and a cross-shaped partition plate 10 was installed inside.
The “straight pipe portion” relating to the invention described in claims 10, 11, 12, and 13 has a diameter of 60 mm, which is 30 mm larger than the outer shape of the cylindrical base, and a height of 60 mm.
As the circulation pump, a centrifugal magnet pump having a casing and an impeller with PTFE lining was used, and the circulation was circulated at an average flow velocity in the tank of 0.006 m / s.

[Comparative Example 1]
As shown in a schematic configuration diagram in FIG. 3, an apparatus including a single porous rectifying plate 21 was applied.
[Comparative Example 2]
As shown in the schematic configuration diagram in FIG. 4, an apparatus including a spherical rectifying layer 22 was applied.
[Comparative Example 3]
As shown in the schematic configuration diagram of FIG. 5, a float type apparatus was applied.

[Example 2]
The one without a current plate was applied. Other conditions were the same as in Example 1.
Example 3
One tapered influent diffusion portion 6 was used. Other conditions were the same as in Example 1.
Example 4
The height of the tapered influent diffusion portion 6 was 50 mm. Other conditions were the same as in Example 1.
Example 5
The straight pipe portion 9 had an inner diameter of 40 mm and a height of 50 mm. Other conditions were the same as in Example 1.

About the said Examples 1-5 and Comparative Examples 1-3, the presence or absence of the shading unevenness of a photoreceptor film was evaluated. The evaluation results are shown in Table 1 below.
◯: No occurrence of shading unevenness on the photoreceptor coating film ×: Occurrence of shading unevenness on the photoreceptor coating film, and evaluation was made in 5 stages (the higher the number, the higher the evaluation).

From the evaluation results of Example 1, the evaluation was clearly better when the two rectifying plates were provided compared to Comparative Example 1 where only one rectifying plate was provided. 7 effect).
From the evaluation results of Comparative Example 3, the occurrence of shading unevenness due to stagnation was not confirmed, but when the dipping and pulling speeds were increased, the gap between the float and the inner wall of the coating tank was narrow, so the flow rate of the gaps was partially increased during pulling It became faster, and vertical stripes of shading were generated.

From the evaluation results of Example 3, it was found that when the number of tapered inflow diffusion portions 6 was singular, unevenness in density occurred in the coating film after circulation for a long time. Compared to the evaluation results of Example 1 provided with a plurality, the results after long-term circulation were inferior.
From this, it was confirmed that it is desirable that the tapered inflow diffusion portion 6 has a configuration in which at least one side of the collective portion 11 is divided every 200 mm or less, and more preferably every 150 mm or less. Effects of a few inventions)

  From the evaluation results of Example 4, it was confirmed that the taper angle of the tapered influent diffusion portion 6 is preferably 45 degrees or less (effect of the invention of claim 8).

  From the evaluation results of Example 5, it was confirmed that the inner diameter of the straight tube portion 9 should be at least 14 mm larger than the outer shape of the photoreceptor substrate, and more preferably twice or more (claims 10 and 11). Effect).

  In addition, from the evaluation results of Example 5, it was confirmed that the height of the straight tube portion 9 is preferably at least more than the outer shape of the photoreceptor substrate, and more preferably 30 mm or more (effects of claims 12 and 13). .

Next, the photoreceptor coated in Example 1 and the photoreceptor coated in Comparative Examples 1 to 3 were modified from a full color laser printer IPSIO Color 5000 manufactured by Ricoh Co., Ltd. (λ = 655 nm, 1200 dpi, An image was formed using a beam spot (modified to 2.7 × 10 ⁻³ mm ² ), and the quality of the image was visually determined.
The halftone image is assumed to be a 2 × 2 dot image, and the photoreceptor was coated after 1 hour circulation, coated after 6 hours circulation, and coated after 1 day circulation. Each sample was extracted and used as an evaluation sample.
The evaluation results are shown in Table 2 below.

  As is apparent from the evaluation results in Table 2, according to the photoconductor manufactured using the electrophotographic photoconductor manufacturing apparatus of the present invention, any electrophotographic photoconductor manufacturing apparatus having the conventional configuration shown in FIGS. It was confirmed that a significantly higher quality image can be obtained than a photoconductor produced using

1 is a schematic configuration diagram of an electrophotographic photoreceptor manufacturing apparatus according to the present invention. The schematic plan view of an example of the principal part of a baffle plate is shown. The schematic block diagram of the conventional electrophotographic photoreceptor manufacturing apparatus is shown. The schematic block diagram of another example of the conventional electrophotographic photoreceptor manufacturing apparatus is shown. The schematic block diagram of another example of the conventional electrophotographic photoreceptor manufacturing apparatus is shown.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Coating liquid stock tank 2 Liquid feeding apparatus 3 Current plate 4 Coating tank 5 Float 6 Tapered inflow liquid spreading | diffusion part 8 Rectification layer (spherical object)
9 Straight pipe portion 10 Cross-shaped partition plate 11 Collecting portion 21 Rectifying plate 22 Rectifying layer

Claims (16)

The coating solution is fed from the coating solution stock tank from the lower part of the coating tank by the feeding device, overflowed from the upper end to control the liquid surface height, and a large number of electrophotographic photoreceptor substrates are immersed at the same time for coating. An electrophotographic photoreceptor manufacturing apparatus having a one-bath structure coating tank,
The one-bath structure coating tank includes a straight pipe portion provided in the same arrangement for each photoreceptor substrate, a collecting portion, and one or more tapered inflow liquid diffusion portions,
2. An electrophotographic photosensitive member manufacturing apparatus, wherein each tapered inflowing liquid diffusion portion is provided with two rectifying plates.   2. The electrophotographic photosensitive member manufacturing apparatus according to claim 1, wherein at least one side of the gathering portion is partitioned by 200 mm or less, and one or more of the tapered inflow liquid diffusion portions are arranged.   2. The electrophotographic photosensitive member manufacturing apparatus according to claim 1, wherein one or more of the tapered inflow liquid diffusing portions are arranged such that one side of the collecting portion is divided every 150 mm or less.   In order to prevent the current plate from interfering with the electrophotographic photosensitive member base during dip coating, the two photosensitive member bases are installed below the lowermost position of the immersion, and one piece is installed at the top of the two. Is the same inner diameter as the inner shape of the gathering part above the tapered inflow liquid diffusion part, and one of them installed at the lowermost part has an inner diameter of the application liquid inflow pipe below the tapered inflow liquid diffusion part. 2. The electrophotographic photosensitive member manufacturing apparatus according to claim 1, wherein the inner diameter is substantially the same.   The electrophotographic photoreceptor manufacturing apparatus according to claim 1, wherein the current plate is a perforated plate.   6. The electrophotographic photoreceptor manufacturing apparatus according to claim 5, wherein the aperture ratio of the perforated plate is in the range of 30% to 60%.   6. The electrophotographic photoreceptor manufacturing apparatus according to claim 5, wherein a hole diameter of the perforated plate is in a range of φ0.5 mm or more and φ5 mm or less.   2. The electrophotographic photoreceptor manufacturing apparatus according to claim 1, wherein a taper angle of the tapered inflowing liquid diffusion portion is 45 degrees or less.   2. The electrophotographic photosensitive member manufacturing apparatus according to claim 1, wherein a cross-shaped partition plate is installed inside the tapered inflowing liquid diffusion portion.   2. The electrophotographic photosensitive member manufacturing apparatus according to claim 1, wherein an inner diameter of the straight tube portions provided in the same arrangement for each of the photosensitive substrate is at least 14 mm larger than an outer shape of the photosensitive substrate.   2. The electrophotographic photoreceptor manufacturing apparatus according to claim 1, wherein an inner diameter of the straight pipe portions provided in the same arrangement for each of the photoreceptor bases is 30 mm or more larger than the outer diameter of the photoreceptor base.   2. The electrophotographic photoreceptor manufacturing apparatus according to claim 1, wherein the height of the straight pipe portions provided in the same arrangement for each of the photoreceptor bases is at least the height of the outer shape of the photoreceptor base.   2. The electrophotographic photoreceptor manufacturing apparatus according to claim 1, wherein the height of the straight pipe portions provided in the same arrangement for each of the photoreceptor bases is at least twice the outer shape of the photoreceptor base.   An electrophotographic photosensitive member manufacturing method, wherein the electrophotographic photosensitive member is manufactured in the coating tank according to claim 1.   An electrophotographic photoreceptor, which is coated with the electrophotographic photoreceptor manufacturing apparatus according to any one of claims 1 to 13. The electrophotographic photosensitive member according to claim 15, wherein the photosensitive layer is an electrophotographic photosensitive member having a laminated structure of a charge generation layer and a charge transport layer.

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