JP2003107760A - Manufacturing method for electrophotographic photoreceptor and electrophotographic photoreceptor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for an electrophotographic photoreceptor having a good coating surface and having no image trouble such as a white spot, a black spot and irregular density in forming an image by an electrophotographic process. SOLUTION: In this manufacturing method for the electrophotographic photoreceptor in which a conductive support is at least coated with pigment dispersion liquid for manufacturing the electrophotographic photoreceptor, the pigment dispersion liquid is filtered by a filter having cotton as filtering material at least once from the time just after producing the pigment dispersion liquid until applying it.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing an electrophotographic photosensitive member, and more particularly to a method for manufacturing an electrophotographic photosensitive member obtained by applying a pigment dispersion filtered through a filter having a specific filter material. It is a thing.

[0002]

2. Description of the Related Art An electrophotographic photosensitive member having a photosensitive layer containing an organic photoconductive substance such as an organic charge generating substance or an organic charge transporting substance as a main component is relatively easy to manufacture and inexpensive. Since it is easy to handle and has many advantages such as excellent thermal stability, it is now the mainstream of electrophotographic photoreceptors and is mass-produced. These electrophotographic photoconductors are used in copying machines, laser printers, and the like.

Among electrophotographic photoconductors using an organic photoconductive substance, a function-separated type photoconductor in which a charge generating function and a charge transporting function are shared by different substances has become mainstream and is widely used. A feature of the function-separated type photoconductor is that a material suitable for each function can be selected from a wide range, and many studies have been conducted since a photoconductor having arbitrary performance can be easily manufactured.

Of these, the substances in charge of the charge generation function include phthalocyanine pigments, squarylium dyes,
Various substances such as azo pigments and perylene pigments have been studied,
Among them, phthalocyanine pigments are expected to be highly sensitive to near-infrared light, so that they are being put to practical use as photoconductor materials for laser printers. Phthalocyanine pigments differ not only in absorption spectrum and photoconductivity depending on the type of central metal, but also in phthalocyanine having the same central metal, these various characteristics are different depending on the crystal form, and the specific crystal form depends on the electrophotographic photoreceptor. It has been reported to have been selected.

As a method for producing an electrophotographic photosensitive member using an organic photoconductive substance, in many cases, a means of immersing the conductive support in a coating solution containing the organic photoconductive substance is adopted. There is. In the case of a function-separated type photoreceptor in which a charge generation layer and a charge transport layer are laminated, a charge generation layer coating liquid (pigment dispersion liquid) obtained by mixing and dispersing a pigment and a binder solution (binder resin solution) It is manufactured by coating a charge transport layer coating solution obtained by mixing a binder solution (binder resin solution) in this order or in the reverse order.

When the pigment dispersion is applied, a filter for filtration is often used in order to remove agglomerated pigment particles and impurities mixed in during the production or application of the dispersion. If you apply a pigment dispersion that is not filtered by a filter, pin holes or uneven density may occur on the coated surface.
The coatability of the pigment dispersion often deteriorates. on the other hand,
Applying a filter-dispersed pigment dispersion alleviates these problems somewhat.

Japanese Patent Laid-Open No. 2001-194809 discloses that
A method using a filtering device using a chemical fiber as a filter medium is disclosed. However, even if the pigment dispersion liquid is filtered with a filtering device using a chemical fiber as a filter material, problems such as pinholes and uneven density occur on the coating surface, and an electrophotographic photoreceptor having a good coating surface. Can't get

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrophotographic image having a good coated surface and free from image defects such as white spots, black spots and uneven density when an image is formed by an electrophotographic process. A method of manufacturing a photoconductor is provided.

[0009]

As a result of various investigations to achieve the above object, the present inventors have conducted electrophotography in which a conductive support is coated with at least a pigment dispersion for producing an electrophotographic photoreceptor. In the method for producing a photoreceptor, it has been found that it is effective to filter the pigment dispersion with a filter using cotton as a filter material at least once between the time immediately after the production of the pigment dispersion and the time of application, and the present invention has been completed. It is a thing.

[0010]

DETAILED DESCRIPTION OF THE INVENTION Each constituent element of the present invention will be described in detail below.

The charge generating substance pigments used in the present invention include azo pigments represented by monoazo pigments, polyazo pigments, metal complex salt azo pigments, pyrazolone azo pigments, stilbene pigments and thiazole azo pigments, and perylene anhydride. Compounds and perylene pigments represented by perylene imide, anthraquinone derivatives, anthanitron derivatives, dibenzpyrenequinone derivatives, pyranthrone derivatives, violanthrone derivatives and isoviolanthrone derivatives, and anthraquinone derivatives or polycyclic quinones. Series pigments, metal phthalocyanines, metal naphthalocyanines,
Examples thereof include phthalocyanine pigments such as metal-free phthalocyanine and metal-free naphthalocyanine. Among these, it is preferable to use a phthalocyanine-based pigment because an electrophotographic photoreceptor having a particularly good coated surface can be obtained by the production method of the present invention.

Among the phthalocyanine-based pigments, titanyloxyphthalocyanine or a phthalocyanine composition containing titanyloxyphthalocyanine and a metal-free phthalocyanine is preferable because it gives an electrophotographic photoreceptor having excellent sensitivity, repetitive characteristics and image characteristics. Among the titanyloxy phthalocyanines, X of CuKα1.541 angstrom
Bragg angle (2θ ± 0.2 °) to the line is 27.2 °
Titanyloxyphthalocyanine having a peak at is preferable, and the Bragg angle is 9.5 °, 13.5 °, 14.2.
Titanyloxyphthalocyanine having peaks at °, 18.0 °, 24.0 °, and 27.2 ° is particularly preferable. Among the phthalocyanine compositions containing titanyloxy phthalocyanine and metal-free phthalocyanine, CuKα1.5
Bragg angle (2θ ± 0.
2 °) has a peak at 27.3 °, and a phthalocyanine composition having a Bragg angle of 7.0 °, 9.0 °,
A phthalocyanine composition having peaks at 14.1 °, 18.0 °, 23.7 °, and 27.3 ° is particularly preferable.

The titanyloxyphthalocyanine used in the present invention can be produced by the method described in Japanese Patent Application Laid-Open No. 11-349841 already proposed.
Further, the phthalocyanine composition used in the present invention can be produced by the method described in Japanese Patent Laid-Open No. 2000-313819 already proposed.

As the binder (binder resin) used in the present invention, acetal resin, butyral resin, vinyl chloride copolymer resin, silicone resin, phenoxy resin,
Examples thereof include phenol resin, epoxy resin, polycarbonate, polyarylate, polyester, polyamide, polyimide, urethane resin and acrylic resin. Among these, by using the acetal resin and the butyral resin, the pigment dispersion exhibits very high dispersibility and the coatability becomes good. Furthermore, by producing an electrophotographic photosensitive member using the dispersion, the charging property, sensitivity, repeatability stability and image characteristics are improved. Therefore, in the present invention, it is particularly preferable to use an acetal resin or a butyral resin as the binder. These resins can be used alone or in combination of two or more.

In the pigment dispersion, the pigment 10 for the charge generating substance is used.
The binder is used in an amount of 10 to 500 parts by weight, preferably 50 to 150 parts by weight, based on 0 part by weight. If the ratio of the resin is too high, the charge generation efficiency of the electrophotographic photosensitive member is lowered, and if the ratio of the resin is too low, there is a problem in film formability.

In the present invention, the solvent used for dispersing the pigment for the charge generating substance may be water or an organic solvent, which may be used alone or as a mixed solvent of two or more kinds. As the organic solvent, alcohol solvents such as methanol, ethanol and isopropyl alcohol, acetone,
Ketone type solvents such as methyl ethyl ketone and methyl isobutyl ketone, ester type solvents such as ethyl formate, ethyl acetate and n-butyl acetate, diethyl ether, 1,2-dimethoxyethane, tetrahydrofuran, 1,3-dioxolane, 1,4-dioxane. , Ether solvents such as anisole, amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, dichloromethane, chloroform, bromoform, methyl iodide, dichloroethane, trichloroethane, trichloroethylene. , Halogenated hydrocarbon solvents such as chlorobenzene, o-dichlorobenzene, fluorobenzene, bromobenzene, iodobenzene, α-chloronaphthalene, n-pentane, n-hexane, n-octane, 1,5-hexadiene Down, cyclohexane, methylcyclohexane, cyclohexadiene, benzene, toluene, o- xylene, m- xylene, p- xylene, ethylbenzene, may be mentioned hydrocarbon solvents such as cumene. Of these, ketone solvents, ester solvents, and ether solvents are particularly preferable.

When the phthalocyanine is dispersed in the present invention, it is preferably dispersed in an organic solvent containing water. If the amount of water added is too small, transition to another crystal form occurs, and if the amount added is too large, poor dispersion or separation of water from the coating liquid, and precipitation of binder from the dispersion solvent may occur, resulting in photosensitization. Not suitable for body preparation. Therefore, the amount of water used in the present invention is preferably 0.1 to 0.95 parts by mass, and 0.3 to 0.9 parts by mass with respect to 1 part by mass of phthalocyanine.
A mass part is more preferable, and 0.5-0.85 mass part is especially preferable.

When water is used in the production of the phthalocyanine dispersion in the present invention, it is preferable to use a water-soluble organic solvent as the organic solvent. Specific examples of the water-soluble organic solvent include 1,2-dimethoxyethane, tetrahydrofuran, 1,3-dioxolane and the like.

The apparatus used to disperse the pigment for the charge generating substance is a dispersing machine using a dispersing medium such as a ball mill, a paint conditioner, a vertical bead mill, a horizontal bead mill and an attritor. As the material of the dispersion medium, soda glass, low alkali glass, and yttria-containing zirconia are preferable, and beads having a diameter of several mm are often used.

As the method for applying the pigment dispersion liquid in the present invention, known methods such as spin coating, blade coating, knife coating, reverse roll coating, rod bar coating and spray coating are used. Further, particularly when coating on a drum, a dipping coating method or the like is used.

In the present invention, the pigment dispersion is filtered at least once with a filter using cotton as a filter medium immediately after the production of the dispersion until the coating. By applying the pigment dispersion filtered through a filter using cotton as a filter material, aggregated pigment particles and the like are easily removed, and pinholes and uneven density are not generated on the application surface. As a result, it is possible to obtain an electrophotographic photosensitive member free from image defects such as white spots, black spots, and uneven density when images are formed by the electrophotographic process.
It is preferable to filter with a filter using cotton as a filter medium immediately before coating the pigment dispersion, because an electrophotographic photoreceptor having a particularly good coating surface can be obtained.

In the present invention, a filter using cotton as a filter medium is used for filtering the pigment dispersion, but a filter having a filter medium other than cotton can be used in combination. Examples of the filter material that may be used include polyethylene, polypropylene, polyester, cellulose acetate, polyether sulfone, tetrafluoroethylene resin, acrylic resin, glass fiber, stainless steel and activated carbon. However, even if a filter having any of these filter materials other than cotton is used, the removal rate of agglomerated pigment particles and the like does not increase, so that it is not effective for obtaining an electrophotographic photoreceptor having a good coated surface.

The filtration device used in the present invention is preferably a filter cartridge type filtration device, but is not limited thereto. Further, in the present invention, it is preferable to use a circulation type coating device having a filtration device (filter), but the present invention is not limited to this.

Any of the electrophotographic photoreceptors of the present invention can be used. For example, there is one in which a photosensitive layer made of a charge generating substance, a charge transporting substance, and a binder is provided on a conductive support. Further, there is also known a laminated type photoreceptor in which a charge generating layer composed of a charge generating substance and a binder and a charge transporting layer composed of a charge transporting substance and a binder are provided on a conductive support. Either the charge generation layer or the charge transport layer may be the upper layer.

In the construction of the electrophotographic photoreceptor of the present invention, an undercoat layer (blocking layer) for controlling charge injection from the photosensitive layer to the conductive support is provided between the photosensitive layer and the conductive support. ) May be provided as necessary, and a surface protective layer may be provided on the surface of the photosensitive layer in order to improve the durability of the photoreceptor. In the case of a laminated type photoreceptor, an intermediate layer may be provided between the charge generation layer and the charge transport layer.

As the conductive support according to the present invention, various ones can be used including those used in well-known electrophotographic photoreceptors. Specifically, for example, gold, silver, platinum, titanium, aluminum, copper, zinc, iron, drums, sheets, belts or the like of conductive treated metal oxides, or laminates of these thin films, vapor depositions and the like can be mentioned. To be

Further, a conductive substance such as metal powder, metal oxide, carbon black, carbon fiber, copper iodide, charge transfer complex, inorganic salt, and ion conductive polymer electrolyte is coated with a suitable binder to form a polymer matrix. Plastic or ceramic embedded in the inside and subjected to conductive treatment,
Examples thereof include drums, sheets, belts and the like made of paper and the like, and drums, sheets, belts and the like of conductive plastics, ceramics, paper and the like containing such a conductive substance.

The undercoat layer is composed of a binder resin alone or a mixture of a binder resin and an inorganic pigment or the like.
Examples of the binder resin include polyamide resins, epoxy resins, urethane resins and the like. Further, examples of the inorganic pigment include titanium oxide, zinc oxide, zirconium oxide and the like.

The thickness of the undercoat layer is determined depending on the surfaceization degree of the conductive support and the electrophotographic characteristics at low temperature and low humidity, and is 0.1 to 30 μm.

When a charge transport material is used in the present invention, the charge transport material used includes a hole transfer material and an electron transfer material. Examples of the hole transfer substance include oxadiazoles, triphenylmethanes, pyrazolines, hydrazones, oxadiazoles, triarylamines and stilbenes. On the other hand, examples of the electron transfer substance include chloranil, tetracyanoethylene, tetracyanoquinodimethane, 2,4,7-trinitro-9-fluorenone, 2,4,5,7-tetranitro-9-fluorenone, 2,4. 5,7-Tetranitroxanthone, 2,
4,8-trinitrothioxanthone, 1,3,7-trinitrodibenzothiophene, 1,3,7-trinitrodibenzothiophene-5,5-dioxide and the like can be mentioned. These charge transport materials may be used alone or in combination of two or more.

In the multi-layer type photoconductor, the charge transport layer is composed of at least these charge transport materials and a binder. As the binder used in the charge transport layer, polystyrene, acrylic resin typified by polymethylmethacrylate, polycarbonate having a skeleton typified by bisphenol A or Z, polyarylate, polyester,
Polyphenylene ether, polyether sulfone, polyamide, polyimide or the like can be used. These binders can be used alone or in combination of two or more.

These binders contained in the charge transport layer are contained in an amount of 0.1 to 20 with respect to 100 parts by mass of the charge transport material.
00 parts by mass is preferable, and 1 to 500 parts by mass is more preferable. If the ratio of the binder is too high, the sensitivity is lowered, and if the ratio of the binder is too low, the repeating properties may be deteriorated or the coating film may be damaged.

In the present invention, when the electrophotographic photoreceptor has a charge transport layer, the charge transport substance and the binder contained in the charge transport layer are used after being dissolved in a solvent. Examples of the solvent used include alcohol solvents such as methanol, ethanol and isopropyl alcohol, ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone, ester solvents such as ethyl formate, ethyl acetate and n-butyl acetate, diethyl ether. , 1,2-dimethoxyethane, tetrahydrofuran, 1,3-dioxolane,
Ether solvents such as 1,4-dioxane and anisole,
Amide solvents such as N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, dichloromethane, chloroform, bromoform, methyl iodide, dichloroethane, trichloroethane, trichloroethylene, chlorobenzene, o-dichlorobenzene, Fluorobenzene, bromobenzene, iodobenzene, α-chloronaphthalene and other halogenated hydrocarbon solvents, n-pentane, n-hexane, n-octane, 1,
5-hexadiene, cyclohexane, methylcyclohexane, cyclohexadiene, benzene, toluene, o-
Hydrocarbon solvents such as xylene, m-xylene, p-xylene, ethylbenzene, cumene and the like can be mentioned.
Of these, ether solvents and halogenated hydrocarbon solvents are particularly preferable.

The electrophotographic photosensitive member of the present invention is 2,6-, in order to prevent deterioration due to oxidation of the organic compound of the constituent material.
It is preferable to add an antioxidant such as di-tert-butyl-p-cresol or DL-α-tocopherol to the photosensitive layer. By adding these antioxidants,
An electrophotographic photosensitive member having excellent repeatability can be obtained.

In the present invention, known methods such as spin coating, blade coating, knife coating, reverse roll coating, rod bar coating, spray coating and the like can be used for coating the undercoat layer coating solution and the charge transport layer coating solution. used. In addition, especially when applying to a drum, dip (dip)
A coating method or the like is used.

[0036]

EXAMPLES The present invention will now be described in more detail by way of examples, which should not be construed as limiting the invention thereto.

Example 1 Alcohol-soluble nylon (manufactured by Toray; CM-8000)
0.2 kg was dissolved in a mixed solvent of 5.5 kg of methanol and 3.6 kg of 1,3-dioxolane. Fine particle titanium oxide (Ishihara Sangyo; TTO-55 (D)) 1.3
After adding kg, the yttria-containing zirconia beads having a diameter of 2 mm were dispersed for 10 hours by a Dyno-mill (manufactured by Shinmaru Enterprises; KD-5 type) as a dispersion medium to obtain a primary dispersion liquid. Next, 2.2 kg of alcohol-soluble nylon (manufactured by Toray; CM-8000) was added to the primary dispersion.
29.5 kg of methanol and 1,3-dioxolane 1
A solution dissolved in a mixed solvent of 9.7 kg was added, and further Dyno-Mill (manufactured by Shinmaru Enterprises; KD-
(5 type) for 2 hours to obtain a secondary dispersion, which was filtered through a filter having polypropylene as a filter material (Advantech Toyo; TCW-10N-PPS) to prepare an undercoat layer coating solution. A filter using polypropylene as a filter material for this coating solution (manufactured by Advantech Toyo; TCW-10N)
-PPD) was applied onto an aluminum tube by a circulation type dip coating apparatus and dried to form an undercoat layer having a film thickness of 0.5 μm.

Butyral resin (manufactured by Sekisui Chemical; B) was added to 2.6 kg of 1,3-dioxolane in which 0.17 kg of water was dissolved.
L-2) 0.02 kg was dissolved, and 0.21 kg of a phthalocyanine composition obtained by the method described in JP-A-2000-313819, which had already been proposed, was added to the solution to give a diameter of A 1 mm low-alkali glass bead was used as a dispersion medium for dispersion for 4 hours with a Dyno-Mill (manufactured by Shinmaru Enterprises; KD-5 type) to obtain a primary dispersion. Next, 0.12 kg of butyral resin (manufactured by Sekisui Chemical; BL-2) was added to this primary dispersion 1,3-
The solution obtained by dissolving in 10.8 kg of dioxolane was added, and the secondary dispersion obtained by further dispersing for 20 minutes with Dyno-Mill (manufactured by Shinmaru Enterprises Co., Ltd .; KD-5 type) was used as a filter medium with cotton. Filter (manufactured by Advantech Toyo; TCW-1-CSS) to prepare a charge generation layer coating solution. This coating solution is applied to the undercoat layer with a circulation type dip coating device having a filter (Advantech Toyo; TCW-1-CSD) using cotton as a filter material, dried, and a charge having a film thickness of about 0.2 μm is applied. A generator layer was formed. Table 1 shows the results of observation for occurrence of pinholes and uneven density on the coated surface of the charge generation layer.

Next, 18 kg of the stilbene compound represented by (1) and polycarbonate (manufactured by Mitsubishi Gas Chemical Co .; Z-4
00) 18 kg, DL-α-tocopherol (RIKEN Vitamin; E1000) 0.4 kg are dissolved in tetrahydrofuran 110 kg, and the resulting charge transport material solution is a filter having polypropylene as a filter material (Advantech Toyo; TCW-10N-). After filtering with PPS, a charge transport layer coating liquid was prepared. A filter using this coating solution with polypropylene as a filter material (Advantech Toyo; TC
W-10N-PPD) is applied on the charge generation layer in the previous period by a circulation type dip coating device and dried to give a dry film thickness of 25 μm.
Was formed on the charge transport layer.

[0040]

[Chemical 1]

The thus prepared electrophotographic photosensitive member was stored at room temperature in a dark place for a whole day and night, then mounted on a commercial office copying machine to form an image, and it was examined whether or not the image had a defect. Table 2 shows the appearance of the obtained copied image.

Example 2 An undercoat layer was formed in the same manner as in Example 1. Next, Example 1
The secondary dispersion liquid of the phthalocyanine composition obtained in the same manner as in (1) was filtered through a filter having polypropylene as a filter material (Advantech Toyo; TCW-1N-PPS) to prepare a charge generation layer coating liquid, and this coating liquid With cotton as a filter material (Advantech Toyo; TCW-1-CS
It was coated on the undercoat layer with a circulation type dip coating apparatus having D) and dried to form a charge generation layer having a thickness of about 0.2 μm. Table 1 shows the results of observation for occurrence of pinholes and uneven density on the coated surface of the charge generation layer. The charge transport layer was formed in the same manner as in Example 1, and the same image evaluation as in Example 1 was performed. The results are shown in Table 2.

Example 3 An undercoat layer was formed in the same manner as in Example 1. Next, Example 1
The secondary dispersion liquid of the phthalocyanine composition obtained in the same manner as above was filtered with a filter having stainless steel as a filter material (Advantech Toyo Co., Ltd .; TSC-3-STCB) to prepare a charge generation layer coating liquid, and this coating liquid With cotton as filter material (Advantech Toyo; TCW-1-CSD)
Was coated on the undercoat layer with a circulation type dip coating apparatus having the above and dried to form a charge generation layer having a thickness of about 0.2 μm. Table 1 shows the results of observation for occurrence of pinholes and uneven density on the coated surface of the charge generation layer. The charge transport layer was formed in the same manner as in Example 1, and the same image evaluation as in Example 1 was performed. The results are shown in Table 2.

Example 4 An undercoat layer was formed in the same manner as in Example 1. Next, Example 1
The secondary dispersion of the phthalocyanine composition obtained in the same manner as in (1) above was filtered through a filter (Advantech Toyo Co., Ltd .; TCW-1-CSS) using cotton as a filter material to prepare a charge generation layer coating solution, and this coating solution was used. A filter using polypropylene as a filter medium (Advantech Toyo; TCW-1N-P
PD) was coated on the undercoat layer by a circulation type dip coating apparatus and dried to form a charge generation layer having a thickness of about 0.2 μm. Table 1 shows the results of observation for occurrence of pinholes and uneven density on the coated surface of the charge generation layer. The charge transport layer was formed in the same manner as in Example 1, and the same image evaluation as in Example 1 was performed. The results are shown in Table 2.

Example 5 An undercoat layer was formed in the same manner as in Example 1. Next, Example 1
The secondary dispersion of the phthalocyanine composition obtained in the same manner as in (1) above was filtered through a filter (Advantech Toyo Co., Ltd .; TCW-1-CSS) using cotton as a filter material to prepare a charge generation layer coating solution, and this coating solution was used. With stainless steel as a filter material (Advantech Toyo; TSC-3-DTC
It was coated on the undercoat layer by a circulation type dip coating apparatus having B) and dried to form a charge generation layer having a thickness of about 0.2 μm. Table 1 shows the results of observation for occurrence of pinholes and uneven density on the coated surface of the charge generation layer. The charge transport layer was formed in the same manner as in Example 1, and the same image evaluation as in Example 1 was performed. The results are shown in Table 2.

Comparative Example 1 An undercoat layer was formed in the same manner as in Example 1. Next, Example 1
The secondary dispersion liquid of the phthalocyanine composition obtained in the same manner as in (1) was filtered through a filter having polypropylene as a filter material (Advantech Toyo; TCW-1N-PPS) to prepare a charge generation layer coating liquid, and this coating liquid With polypropylene as the filter material (Advantech Toyo; TC
W-1N-PPD) was applied on the undercoat layer by a circulation type dip coating apparatus and dried to form a charge generation layer having a thickness of about 0.2 μm. Table 1 shows the results of observation for occurrence of pinholes and uneven density on the coated surface of the charge generation layer.
Shown in. The charge transport layer was formed in the same manner as in Example 1, and the same image evaluation as in Example 1 was performed. The results are shown in Table 2.

Comparative Example 2 An undercoat layer was formed in the same manner as in Example 1. Next, Example 1
The secondary dispersion liquid of the phthalocyanine composition obtained in the same manner as in (1) was filtered through a filter having polypropylene as a filter material (Advantech Toyo; TCW-1N-PPS) to prepare a charge generation layer coating liquid, and this coating liquid Filter with polyester as the filter material (Advantech Toyo; TCW
−1-EPD) was applied to the undercoat layer by a circulation type dip coating apparatus and dried to form a charge generation layer having a thickness of about 0.2 μm. Table 1 shows the results of observation for occurrence of pinholes and uneven density on the coated surface of the charge generation layer. The charge transport layer was formed in the same manner as in Example 1, and the same image evaluation as in Example 1 was performed. The results are shown in Table 2.

Comparative Example 3 An undercoat layer was formed in the same manner as in Example 1. Next, Example 1
The secondary dispersion liquid of the phthalocyanine composition obtained in the same manner as in (1) was filtered through a filter having polypropylene as a filter material (Advantech Toyo; TCW-1N-PPS) to prepare a charge generation layer coating liquid, and this coating liquid Is applied onto the undercoat layer with a circulation type dip coating device having a filter (Advantech Toyo; TCR-080-DBFE) using cellulose acetate as a filter material and dried to form a charge generation layer having a thickness of about 0.2 μm. Was formed. Table 1 shows the results of observation for occurrence of pinholes and uneven density on the coated surface of the charge generation layer. The charge transport layer was formed in the same manner as in Example 1, and the same image evaluation as in Example 1 was performed. The results are shown in Table 2.

Comparative Example 4 An undercoat layer was formed in the same manner as in Example 1. Next, Example 1
The secondary dispersion liquid of the phthalocyanine composition obtained in the same manner as in (1) was filtered through a filter having polypropylene as a filter material (Advantech Toyo; TCW-1N-PPS) to prepare a charge generation layer coating liquid, and this coating liquid Is coated on the undercoat layer with a circulation type dip coating device having a filter (Advantech Toyo Co., Ltd .; TCF-100-D1FE) using a tetrafluoroethylene resin as a filter material and dried to give a film thickness of about 0.2 μm. A charge generation layer was formed. Table 1 shows the results of observation for occurrence of pinholes and uneven density on the coated surface of the charge generation layer. The charge transport layer was formed in the same manner as in Example 1, and the same image evaluation as in Example 1 was performed. The results are shown in Table 2.

Comparative Example 5 An undercoat layer was formed in the same manner as in Example 1. Next, Example 1
The secondary dispersion liquid of the phthalocyanine composition obtained in the same manner as in (1) was filtered through a filter having polypropylene as a filter material (Advantech Toyo; TCW-1N-PPS) to prepare a charge generation layer coating liquid, and this coating liquid Filter using activated carbon as a filter medium (Advantech Toyo; TCC-W1
-D0C0) was applied to the undercoat layer by a circulation type dip coating apparatus and dried to form a charge generation layer having a thickness of about 0.2 μm. Table 1 shows the results of observation for occurrence of pinholes and uneven density on the coated surface of the charge generation layer. The charge transport layer was formed in the same manner as in Example 1, and the same image evaluation as in Example 1 was performed. The results are shown in Table 2.

Comparative Example 6 An undercoat layer was formed in the same manner as in Example 1. Next, Example 1
The secondary dispersion liquid of the phthalocyanine composition obtained in the same manner as in (1) was filtered through a filter having polypropylene as a filter material (Advantech Toyo; TCW-1N-PPS) to prepare a charge generation layer coating liquid, and this coating liquid With stainless steel as a filter material (Advantech Toyo; TSC-
3-DTCB) was applied onto the undercoat layer with a circulation type dip coating apparatus and dried to form a charge generation layer having a thickness of about 0.2 μm. Table 1 shows the results of observation for occurrence of pinholes and uneven density on the coated surface of the charge generation layer. The charge transport layer was formed in the same manner as in Example 1, and the same image evaluation as in Example 1 was performed. The results are shown in Table 2.

Comparative Example 7 An undercoat layer was formed in the same manner as in Example 1. Next, Example 1
The secondary dispersion liquid of the phthalocyanine composition obtained in the same manner as above was filtered with a filter having stainless steel as a filter material (Advantech Toyo Co., Ltd .; TSC-3-STCB) to prepare a charge generation layer coating liquid, and this coating liquid With stainless steel as a filter material (Advantech Toyo; TSC-3-
The charge generation layer having a film thickness of about 0.2 μm was formed by coating on the undercoat layer with a circulation type dip coating apparatus having DTCB) and drying. Table 1 shows the results of observation for occurrence of pinholes and uneven density on the coated surface of the charge generation layer.
The charge transport layer was formed in the same manner as in Example 1, and the same image evaluation as in Example 1 was performed. The results are shown in Table 2.

[0053]

[Table 1]

[0054]

[Table 2]

In Comparative Examples 1 to 7, pinholes and density unevenness occurred on the coated surface of the charge generation layer. Further, when the electrophotographic photosensitive member was mounted on a copying machine and an image was formed, a large number of white spots and black spots were generated in addition to density unevenness, and image defects were observed. On the other hand, in Examples 1 to 5, the pigment particles and the like that were aggregated during the filtration of the pigment dispersion liquid were easily removed, and pinholes and density unevenness were hardly seen on the coating surface of the charge generation layer, which was excellent. An electrophotographic photosensitive member having a coated surface was obtained. Further, there was almost no image failure when the electrophotographic photosensitive member was mounted on a copying machine to form an image. Among these, in Examples 1 to 3 filtered with a filter using cotton as a filter material immediately before coating the pigment dispersion, an electrophotographic photoreceptor having a particularly good coating surface is obtained,
The image characteristics were also very good.

[0056]

As is apparent from the above, according to the present invention, an image failure such as white spots, black spots, and uneven density occurs when an image is formed by an electrophotographic process having a good coating surface. It is possible to provide a method for manufacturing a non-electrophotographic photoreceptor.

Claims (9)

[Claims] 1. In a method for producing an electrophotographic photosensitive member in which a conductive support is coated with at least a pigment dispersion for producing an electrophotographic photosensitive body, at least once between the production of the pigment dispersion and the coating. A method for producing an electrophotographic photosensitive member, which comprises filtering the pigment dispersion with a filter using cotton as a filter material. 2. The method for producing an electrophotographic photosensitive member according to claim 1, wherein the pigment dispersion liquid is a phthalocyanine dispersion liquid. 3. The method for producing an electrophotographic photosensitive member according to claim 1, wherein the pigment dispersion liquid is a dispersion liquid of titanyloxyphthalocyanine. 4. The Bragg angle (2θ ± 0.2 °) with respect to an X-ray of CuKα1.541 angstrom, wherein the pigment dispersion is
Is a dispersion liquid of titanyloxyphthalocyanine having a peak at 27.2 °, The method for producing an electrophotographic photosensitive member according to claim 1, wherein 5. The Bragg angle (2θ ± 0.2 °) with respect to an X-ray of CuKα1.541 angstrom, wherein the pigment dispersion liquid is
Are further 9.5 °, 13.5 °, 14.2 °, 18.0
The method for producing an electrophotographic photosensitive member according to claim 1, which is a dispersion liquid of titanyloxyphthalocyanine having peaks at °, 24.0 ° and 27.2 °. 6. The method for producing an electrophotographic photosensitive member according to claim 1, wherein the pigment dispersion liquid is a dispersion liquid of a phthalocyanine composition containing titanyloxyphthalocyanine and a metal-free phthalocyanine. 7. The pigment dispersion is a dispersion of a phthalocyanine composition containing titanyloxyphthalocyanine and a metal-free phthalocyanine, and the composition is CuKα.
Bragg angle (2θ of 1.541 angstrom X-ray)
2. The method for producing an electrophotographic photosensitive member according to claim 1, wherein a peak of ± 0.2 °) is 27.3 °. 8. The pigment dispersion is a dispersion of a phthalocyanine composition containing titanyloxyphthalocyanine and a metal-free phthalocyanine, and the composition is CuKα.
Bragg angle (2θ of 1.541 angstrom X-ray)
± 0.2 °) is 7.0 °, 9.0 °, 14.1 °, 1
The method for producing an electrophotographic photosensitive member according to claim 1, which has peaks at 8.0 °, 23.7 °, and 27.3 °. 9. An electrophotographic photosensitive member manufactured by the method for manufacturing an electrophotographic photosensitive member according to claim 1.