JP2001312078A - Electrophotographic photoreceptor and method for manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To manufacture a photoreceptor by a dip coat method using a coating liquid containing a mixture solvent with rather low viscosity to form a coating film without forming a buildup of the liquid on the lower end of the body or without decreasing the productivity, and to obtain high picture quality by using the photoreceptor. SOLUTION: A coating liquid 12 containing at least two kinds of solvents is used to form a coating film on a conductive base body 2 by a dip coat method to manufacture a photoreceptor. The coating liquid 12 contains methylphenyl silicone oil or dimethylsilicone oil, and the viscosity of the liquid 12 is specified to <=20 mPa.s. The coating liquid 12 is used for the charge generating layer or the base coating layer of the photoreceptor. The viscosity of the silicone oil is 5 to 50 mPa.s, and the add amount of the silicone oil is 1 to 20 wt.% to the solid content of the liquid 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic photosensitive member manufactured by dip-coating a coating solution containing at least two kinds of solvents and a method for manufacturing the same.

[0002]

2. Description of the Related Art As a material constituting a photosensitive layer of a photoreceptor,
Conventionally, inorganic photoconductive materials such as selenium, cadmium sulfide, and zinc oxide have been known. A photoreceptor using these inorganic photoconductive materials can be charged to an appropriate potential in a dark place, for example, and has a small charge dissipation in a dark place.
It has the advantage that the charge can be quickly dissipated by light irradiation, but also has various disadvantages. For example,
Photoreceptors using selenium require high manufacturing costs due to difficult manufacturing conditions and are susceptible to heat and mechanical shock, so care must be taken when handling them. The photoreceptor using cadmium sulfide and zinc oxide did not provide stable sensitivity in a humid environment, and the dye added as a sensitizer was stable over a long period of time due to charge deterioration due to corona charging and photobleaching due to exposure. Can't give properties.

With respect to such an inorganic photoconductive material,
Various organic photoconductive materials such as polyvinyl carbazole have been proposed. Organic photoconductive materials are superior to inorganic photoconductive materials in terms of film formability and lightness, but are inferior in sufficient sensitivity, durability, and stability due to environmental changes. In recent years, various researches and developments have been made to solve these drawbacks, and a stacked type or a dispersed type in which the charge generation function and the charge transport function of the photoconductive function are respectively assigned to different substances. A function-separated type photoconductor, which is a mold, has been proposed. Function-separated type photoreceptors have a wide selection range of each substance, charging characteristics, sensitivity,
A high-performance photoreceptor can be provided by combining the best substances in electrophotographic characteristics such as residual potential, repetition characteristics and printing durability. Further, since it can be produced by a coating method, an extremely high productivity and inexpensive photoreceptor can be provided, and the photosensitive wavelength range can be freely controlled by appropriately selecting the charge generating material.

In recent years, digitization of image formation has been rapidly progressing in order to obtain higher quality images and to store and freely edit input images. Until now, image forming apparatuses for digitally forming images have been limited to laser printers, LED printers and some color laser copiers (registered trademark) as output devices of word processors and personal computers. Digitization is also progressing in the field of copiers where image formation was the mainstream.

In such digital image formation,
When using computer information, the electrical signal is converted to an optical signal. When inputting information from a document, the document information is read as optical information, then converted to a digital electrical signal, and then converted to an optical signal again. Is input to the photoconductor. In any case, an optical signal is input to the photoconductor, but laser light or LED light is mainly used for optical input of such a digital signal. Currently, the most frequently used input light oscillation wavelength is 780 nm or 660 n.
m near-infrared light and long-wavelength light close thereto. For a photoreceptor used for digital image formation, the first requirement is to have sensitivity to these long-wavelength lights, and various materials have been studied so far. In particular, phthalocyanine compounds are relatively easy to synthesize, and many of them are sensitive to long-wavelength light, and are therefore widely used in practice.

For example, Japanese Patent Publication No. 5-55860 discloses a photoreceptor using oxotitanium phthalocyanine, JP-A-59-155851 discloses a photoreceptor using β-type indium phthalocyanine, and JP-A-2-233969 discloses an X-type photoreceptor. A photosensitive member using a metal-free phthalocyanine is disclosed in
8557 discloses a photoreceptor using vanadyloxyphthalocyanine.

Further, it has been found that oxotitanium phthalocyanine having a specific crystal form has a particularly high sensitivity. Japanese Patent No. 2,285,593 discloses that the X-ray diffraction spectrum has a maximum diffraction at a Bragg angle (2θ ± 2 °) of 27.3 °. An oxotitanium phthalocyanine having a peak and peaks at 7.4 °, 9.7 ° and 24.2 ° is disclosed in Japanese Patent No. 2700859 as having a Bragg angle (2θ ± 2 °) of 9.5 ° in an X-ray diffraction spectrum. , 9.7 °, 11.7
°, 15.0 °, 23.5 °, 24.1 ° and 27,
Each oxo titanium phthalocyanine having a peak at 3 ° is disclosed.

However, phthalocyanine generally has an unstable crystal form, and has a disadvantage that the crystal form is changed in a dispersion step in preparing a coating solution for a photosensitive layer, and the performance is not sufficiently brought out. In order to solve such disadvantages, various dispersing solvents have been studied.However, the solvent for stabilizing the crystal form is not always excellent in coating properties, productivity and dispersion stability, In order to achieve a balance between productivity and productivity, a mixed solvent is often used.
Also, in azo pigments exhibiting sensitivity to long-wavelength light, as disclosed in JP-A-7-110587, two or more solvents are used as a dispersing solvent in order to improve the dispersion stability of the coating liquid. You are increasing.

When a charge photographic photoreceptor is prepared by a dip coating method using a pigment dispersion composed of such a relatively low-viscosity mixed solvent, a substrate such as an aluminum drum is formed from the coating liquid. When pulled up, ring-shaped coating unevenness of several mm to several cm (hereinafter, referred to as “liquid rise”) occurs at the lower end of the drum. If the liquid rises, the portion cannot be used for image formation, so the effective image area on the photoreceptor is reduced by that much or the drum is used to secure the effective image area even if the liquid rises. It is necessary to take measures such as increasing the length, and the image quality is reduced and the manufacturing cost is increased. Conventionally, to prevent the liquid from rising, there is a measure such as reducing the pulling speed only immediately before the lower end of the drum comes out of the coating liquid.However, this measure requires changing the pulling speed of the drum, thus increasing productivity. Decrease. The mechanism of the rise of the liquid is considered as follows. When a mixed solvent is used, the surface tension and the evaporation rate between the solvents naturally differ. Therefore, in the process of natural drying immediately after coating, the difference in surface tension between the relatively fast-dried portion and the slowly dried portion increases, and the undried liquid at the lower end of the drum is pulled upward by the surface tension. The liquid rises.

[0010] Japanese Patent No. 2853336 discloses a technique in which a phthalocyanine and a butyral resin are mainly used as a charge generation layer, and a coating liquid in which this is dispersed in a mixed solvent of a low-viscosity solvent and a high-viscosity solvent is used. However, this technique aims at preventing coating film defects due to aggregation of pigments.
Also, Japanese Patent Application Laid-Open No. 7-295247 discloses a technique in which a charge generation material, a binder resin, and a coating solution containing polydimethylsiloxane are used as a charge generation layer.
This technique aims at reducing local unevenness of the coating film. Further, Japanese Patent Application Laid-Open No. 6-222578 discloses a technique in which a coating liquid containing silicone oil is used as a charge generation layer in a sheet-shaped photoreceptor. The purpose is to prevent defects due to repelling and uneven coating of the charge generation layer. None of these three prior arts can prevent the above-mentioned liquid rise.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an electrophotographic photoreceptor capable of obtaining a high image quality without liquid rise, and to use a coating liquid containing a mixed solvent having a relatively low viscosity. An object of the present invention is to provide a method for producing an electrophotographic photoreceptor capable of forming a coating film by a dip coating method without causing a liquid rise at the lower end of a substrate and without lowering productivity.

[0012]

According to a first aspect of the present invention, there is provided a method for producing an electrophotographic photosensitive member in which a coating film is formed on a conductive substrate by a dip coating method using a coating solution containing at least two kinds of solvents. A method for producing an electrophotographic photoreceptor, wherein the coating liquid contains silicone oil, and the viscosity of the coating liquid is 20 mPa · s or less.

According to the present invention, when a coating film is formed on a conductive substrate by a dip coating method using a coating solution containing at least two kinds of solvents, the viscosity of the coating solution is 20 mPa · s.
In addition, since the coating liquid contains silicone oil, it is possible to prevent a liquid rise which is an abnormality of a coating film when producing a photosensitive layer.

In a second aspect of the present invention, the silicone oil is methylphenyl silicone oil.

According to the present invention, since the silicone oil is a methylphenyl silicone oil, it is possible to prevent a liquid rise which is a coating film abnormality.

A third aspect of the present invention is characterized in that the silicone oil is dimethyl silicone oil.

According to the present invention, since the silicone oil is dityl phenyl silicone oil, it is possible to prevent a liquid rise which is a coating film abnormality.

A fourth aspect of the present invention is characterized in that the coating liquid is a coating liquid for a charge generation layer.

According to the present invention, since the coating liquid is a coating liquid for a charge generating layer, it is possible to prevent a liquid rise which is an abnormality of a coating film when forming the charge generating layer.

A fifth aspect of the present invention is characterized in that the coating liquid is a coating liquid for an undercoat layer.

According to the present invention, since the coating liquid is a coating liquid for an undercoat layer, it is possible to prevent a rise of the liquid, which is an abnormal coating film, when the undercoat layer is formed.

The sixth invention is characterized in that the viscosity of the silicone oil is in the range of 5 to 50 mPa · s.

According to the present invention, since the viscosity of the silicone oil is in the range of 5 to 50 mPa · s, it is possible to prevent a liquid rise which is a coating film abnormality.

A seventh aspect of the present invention is characterized in that the addition amount of the silicone oil is in the range of 1 to 20% by weight based on the solid content of the coating liquid.

According to the present invention, the addition amount of the silicone oil is in the range of 1 to 20% by weight based on the solid content of the coating liquid, so that the liquid rise which is abnormal in the coating film can be effectively prevented. Can be.

An eighth aspect of the present invention is characterized in that the solvent of the coating solution for the charge generating layer is a mixed solvent of a ring-type ketone solvent and an aliphatic ketone solvent.

According to the present invention, since the solvent of the coating solution for the charge generating layer is a mixed solvent of a ring-type ketone solvent and an aliphatic ketone solvent, the coating film is abnormal at the time of preparing the charge generating layer. Liquid rise can be prevented.

A ninth aspect of the present invention is characterized in that the solvent of the coating solution for the charge generation layer is a mixed solvent of a ring-type ketone solvent and an ester solvent.

According to the present invention, since the solvent of the coating solution for the charge generation layer is a mixed solvent of a ring-type ketone solvent and an ester solvent, the liquid rise which is an abnormality of the coating film during the preparation of the charge generation layer. Can be prevented.

A tenth aspect of the present invention is characterized in that the solvent of the coating solution for the charge generation layer is a mixed solvent of a ring-type ketone solvent and an ether solvent.

According to the present invention, since the solvent of the coating solution for the charge generation layer is a mixed solvent of a ring-type ketone solvent and an ether solvent, the liquid rise which is an abnormality of the coating film during the preparation of the charge generation layer. Can be prevented.

The eleventh aspect of the present invention is that the mixed solvent of the finger-ring ketone solvent and the aliphatic ketone solvent is a mixed solvent of cyclohexanone and an aliphatic ketone solvent, and the cyclohexanone and the aliphatic ketone solvent are mixed solvents. Weight ratio of cyclohexanone / aliphatic ketone solvent is 5/95 to 5
It is characterized by being in the range of 0/50.

According to the present invention, the mixed solvent of the ring-type ketone solvent and the aliphatic ketone solvent is a mixed solvent of cyclohexanone and an aliphatic ketone solvent, and the mixed solvent of cyclohexanone and the aliphatic ketone solvent is used. Weight ratio of cyclohexanone / aliphatic ketone solvent is 5/95 to 50/5
Since it is in the range of 0, it is possible to effectively prevent the liquid rise which is a coating film abnormality at the time of producing the charge generation layer.

In a twelfth aspect of the present invention, the mixed solvent of the finger ring ketone solvent and the ester solvent is a mixed solvent of cyclohexanone and the ester solvent, and the weight ratio of the cyclohexanone and the ester solvent is cyclohexanone. / Ester solvent in the range of 5/95 to 50/50.

According to the present invention, the mixed solvent of the finger-ring ketone solvent and the ester solvent is a mixed solvent of cyclohexanone and the ester solvent, and the weight ratio of the cyclohexanone and the ester solvent is cyclohexanone /
Since the ratio of the ester solvent is in the range of 5/95 to 50/50, it is possible to effectively prevent the liquid rise, which is an abnormality of the coating film when the charge generation layer is formed.

According to a thirteenth aspect of the present invention, the mixed solvent of the ring-type ketone solvent and the ether solvent is a mixed solvent of cyclohexanone and an ether solvent, and the weight ratio of cyclohexanone and the ether solvent is cyclohexanone / It is characterized by being in the range of 5/95 to 50/50 with an ether solvent.

According to the present invention, the mixed solvent of the finger ring ketone solvent and the ether solvent is a mixed solvent of cyclohexanone and an ether solvent, and the weight ratio of the cyclohexanone and the ether solvent is cyclohexanone / ether solvent. Since the ratio of the solvent is in the range of 5/95 to 50/50, it is possible to effectively prevent the liquid rise, which is an abnormality of the coating film when the charge generation layer is prepared.

In the fourteenth invention, the solvent for the undercoat layer coating liquid is a mixed solvent of dioxolane and an alcohol solvent, and the undercoat layer coating liquid contains an alcohol-soluble nylon resin. It is characterized by the following.

According to the present invention, since the solvent of the undercoat layer coating liquid is a mixed solvent of dioxolane and an alcohol-based solvent, and the undercoat layer coating liquid contains an alcohol-soluble nylon resin, It is possible to prevent a liquid rise which is an abnormality of a coating film when forming a layer.

A fifteenth aspect of the present invention is characterized in that the mixed solvent of dioxolane and the alcohol solvent is a mixed solvent of dioxolane and methanol.

According to the present invention, since the mixed solvent of dioxolane and the alcohol-based solvent is a mixed solvent of dioxolane and methanol, it is possible to effectively prevent the liquid rise, which is an abnormality in the coating film during the preparation of the undercoat layer. Can be.

A sixteenth aspect of the present invention is an electrophotographic photosensitive member having a photosensitive layer on a conductive substrate, wherein at least one layer formed on the conductive substrate is formed by the method of the first aspect of the present invention. An electrophotographic photoreceptor, characterized in that the electrophotographic photoreceptor is a coated layer.

According to the present invention, in an electrophotographic photoreceptor having a photosensitive layer on a conductive substrate, at least one layer formed on the conductive substrate is formed by the method of the first present invention. A larger area can be used as the effective image area.

According to a seventeenth aspect of the present invention, there is provided an electrophotographic photoreceptor having at least a charge generation layer and a charge transport layer on a conductive substrate, wherein at least the charge generation layer is formed by the method of the fourth invention. An electrophotographic photoreceptor, characterized in that the electrophotographic photoreceptor is a transparent layer.

According to the present invention, in an electrophotographic photoreceptor having at least a charge generating layer and a charge transporting layer on a conductive substrate, at least the charge generating layer is formed by the method of the fourth present invention. A large area can be used as an effective image area.

According to an eighteenth aspect of the present invention, there is provided an electrophotographic photoreceptor having at least an undercoat layer and a photosensitive layer on a conductive substrate, wherein at least the undercoat layer is formed by the method of the fifth invention. An electrophotographic photosensitive member, which is a layer.

According to the present invention, in an electrophotographic photoreceptor having at least an undercoat layer and a photosensitive layer on a conductive substrate, since at least the undercoat layer is formed by the method of the fifth invention, a larger size is obtained. The area can be used as the effective image area.

According to a nineteenth aspect of the present invention, an electrostatic latent image is formed by charging the surface of an electrophotographic photoreceptor to a predetermined potential, exposing the same, developing the formed electrostatic latent image with a developer, and performing recording. An image forming apparatus for forming an image by an electrophotographic method in which the image is transferred to a material and fixed, wherein the electrophotographic photoreceptor has 16 to 1
An image forming apparatus comprising the electrophotographic photoreceptor according to any one of the eighth to eighth aspects of the present invention.

According to the present invention, the image forming apparatus is a sixteenth to
Since the electrophotographic photoreceptor of the present invention is provided with the eighteenth aspect, an image of good quality with few image defects can be obtained.

[0050]

FIG. 1 is a view showing a dip coating apparatus 10 used in a method of manufacturing an electrophotographic photosensitive member according to an embodiment of the present invention. FIG. 2 is a cross-sectional view of the electrophotographic photoreceptor 1 manufactured by the manufacturing method. Photoconductor 1
Denotes a function-separated type photoconductor, in which an undercoat layer (intermediate layer) 3 is formed on a conductive substrate 2, and a photosensitive layer 6 is formed on the undercoat layer 3.
Is formed. The photosensitive layer 6 is configured by laminating the charge generation layer 4 and the charge transport layer 5. In FIG. 2, the charge generation layer 4 is formed on the undercoat layer 3 and the charge transport layer 5 is formed on the charge generation layer 4, but the charge generation layer 4 and the charge transport layer 5 are reversed. It may be formed.

Of the undercoat layer 3, the charge generation layer 4 and the charge transport layer 5 formed on the substrate 2, at least the undercoat layer 3 and the charge generation layer 4 are formed by a dip coating method using a dip coating device 10. Formed by In the dip coating apparatus 10, the coating liquid 12 for the undercoat layer or the charge generation layer is filled with the coating liquid tank 1.
1 and a predetermined base 2 is fixed to the arm 14. The arm 14 moves up and down by driving a motor 15 of the lifting device 13. The base 2 fixed to the arm 14 is immersed in the coating liquid 12 by the lifting device 13 and then pulled up. By evaporating the solvent from the coating liquid 12 applied to the base 2, the undercoat layer 3 or the charge generation layer 4 is formed on the base 2.

The undercoat layer 3 is formed as required, and the photosensitive layer 6 may be formed directly on the conductive substrate 2. Further, the photoconductor is not limited to the function-separated type photoconductor 1 in which the photosensitive layer 6 includes the charge generation layer 4 and the charge transport layer 5 as described above, and the charge generation layer 4 and the charge transport layer 5 are not separated. Alternatively, the photosensitive layer 6 may be of a single-layer type composed of a single layer. In the case of a single layer type, the photosensitive layer 6 is
It is formed by a dip coating method using Coating liquid tank 11
Contains a coating solution 12 for a photosensitive layer, and forms a photosensitive layer 6 in the same manner as the undercoat layer 3 and the charge generation layer 4 described above.

FIG. 3 is a view showing an image forming apparatus 21 on which the photosensitive member 1 is mounted. The image forming apparatus 21 includes at least a charging device 2 around the rotatable photosensitive member 1.
2, an exposure device 23, a developing device 24, a transfer device 26, and a fixing device 27. In FIG. 3, a cleaning device 28 and a charge removing device 29 are further provided. After the surface of the photoconductor 1 is charged to a predetermined potential by the charging device 22, a latent image is formed by exposure of the exposure device 23. The formed latent image is developed with a developer by the developing device 24, and thus a visible image is formed on the surface of the photoconductor 1. The formed visible image is transferred to the recording paper 25 conveyed to the transfer position by the transfer device 26, and is fixed by the fixing device 27. Thus, an image is formed on the recording paper 25. The developer remaining on the photoreceptor 1 after the transfer is cleaned by the cleaning device 28, and after the remaining charge is removed by the charge removing device 29, the steps after charging are repeated.

Examples of usable conductive substrate 2 include drums and sheets made of metal such as aluminum, aluminum alloy, copper, zinc, nickel, stainless steel and titanium. Also, polyethylene terephthalate,
Polymer materials such as phenolic resin, nylon and polystyrene, glass and rigid paper drums, sheets and seamless belts, laminated metal foil, metal evaporated, titanium oxide, tin oxide, indium oxide And a conductive material such as carbon black, which has been subjected to a conductive treatment by being applied together with a suitable binder resin.

The undercoat layer 3 is provided for improving the adhesiveness of the photosensitive layer 6 to the substrate 2 and the charge blocking property from the substrate 2. Considering that the undercoat layer 3 generally contains a resin as a main component and the photosensitive layer 6 is formed on the undercoat layer 3 by using a solvent, the resin is resistant to a general organic solvent. It is preferable that the resin has high property. Examples of such a resin include water-soluble resins such as polyvinyl alcohol, casein and sodium polyacrylate,
Curable resins that form a three-dimensional network structure, such as alcohol-soluble resins such as copolymerized nylon and methoxymethylated nylon, acrylic resins, polyurethanes, melamine resins, phenolic resins, and epoxy resins. For the purpose of preventing moiré and reducing the residual potential, a fine powder pigment of a metal oxide such as titanium oxide, silica, alumina, zirconium oxide, tin oxide and indium oxide may be added to the undercoat layer 3.

The thickness of the undercoat layer 3 is 0.1 μm or more and 20 μm or more.
It is preferably in the range of 1 μm or less, particularly in the range of 1 μm or more and 5 μm or less. When the thickness of the undercoat layer 3 is smaller than 0.1 μm, the undercoat layer 3 does not substantially function as an undercoat layer 3 and a uniform surface property covering defects of the conductive substrate 2 cannot be obtained. Carrier injection cannot be prevented, and the chargeability is reduced. Further, it is not preferable to form the undercoat layer 2 with a film thickness larger than 20 μm because it becomes difficult to form the undercoat layer 2 by the dip coating method, and the mechanical strength of the coating film is reduced.

The undercoat layer coating solution is prepared by dissolving the resin in a solvent and dispersing the fine powder of the metal oxide. Examples of usable solvents include alcohol solvents such as methanol and ethanol, ketone solvents such as methyl ethyl ketone and cyclohexanone, and ether solvents such as tetrahydrofuran. The dispersion of the coating liquid for the undercoat layer is performed by using a ball mill, a sand mill,
An attritor, a vibration mill, a colloid mill, an ultrasonic disperser, and the like are used. According to the present invention, the undercoat layer 3
The undercoat layer 3 can be formed by a general method such as a spray method, a bead method, and a nozzle method.

In the function-separated type photoconductor 1, the charge generation layer 4 contains a charge generation substance and a binder resin. As the charge generating material, bisazo compounds such as chlorodiane blue, polycyclic quinone compounds such as dibromoansansthrone, perylene compounds, quinacridone compounds, phthalocyanine compounds and azulhenium salt compounds are known. May be used alone or in combination of two or more.

The binder resin contained in the charge generation layer 4 includes melamine resin, epoxy resin, silicone resin, polyurethane resin, acrylic resin, polycarbonate resin,
Examples include polyarylate resins, phenoxy resins and butyral resins, and also include insulating copolymer resins containing two or more repeating units such as vinyl chloride-vinyl acetate copolymer resins and acrylonitrile styrene copolymer resins. However, the present invention is not limited thereto, and all commonly used resins can be used alone or in combination of two or more.

The thickness of the charge generation layer 4 is preferably in the range of 0.05 μm to 5 μm, particularly preferably in the range of 0.1 μm to 1 μm. When the thickness of the charge generation layer 4 is smaller than 0.05 μm, light is not substantially absorbed, and a disadvantage occurs in that the sensitivity is reduced. On the other hand, when the film thickness is larger than 5 μm, the generation of heat carriers increases, and the inconvenience of lowering the chargeability occurs.

The coating solution for the charge generating layer is prepared by mixing and dispersing the charge generating substance in a solution in which the binder resin is dissolved in a solvent. Examples of usable solvents include halogenated hydrocarbons such as methylene chloride and ethane dichloride,
Ketones such as acetone, methyl ethyl ketone and cyclohexanone, esters such as ethyl acetate and butyl acetate, ethers such as tetrahydrofuran and dioxane, aromatic hydrocarbons such as benzene, toluene and xylene, and N, N-dimethylformamide and N , N-dimethylacetamide and the like.

According to the present invention, the charge generation layer 4 is formed by a dip coating method, but the charge generation layer 4 can be formed by the same general method as that of the undercoat layer 3.

In the photoreceptor 1 of the function separation type, the charge transport layer 5 contains a charge transport material and a binder resin. Examples of the charge transport material include hydrazone compounds, pyrazoline compounds, triphenylamine compounds, triphenylmethane compounds, stilbene compounds, oxadiazole compounds, enamine compounds, and the like. More than one species can be used in combination.
As the binder resin, one of the binder resins listed for the charge generation layer 4 is used.
Species or a mixture of two or more can be used.

The thickness of the charge transport layer 5 is 5 μm or more and 50 μm or more.
m, particularly preferably in the range of 10 μm to 40 μm. If the thickness of the charge transport layer 5 is smaller than 5 μm, there is a disadvantage that the charge holding ability is significantly reduced. On the other hand, when the film thickness is larger than 50 μm, it is difficult to form a uniform film, and there is a disadvantage that productivity is reduced.

The coating solution for the charge transport layer is prepared by dissolving the charge transport material in a solution in which the binder resin is dissolved in a solvent. Usable solvents include, for example, dichloromethane, tetrahydrofuran, dioxane, dioxolane and the like.

The charge transport layer 5 may be formed by the dip coating method similarly to the undercoat layer 3 and the charge generation layer 4, or by the same general method as the undercoat layer 3 except for the dip coating method. It may be formed.

In the single-layer type photoreceptor, the photosensitive layer 6 contains the charge generating substance, the charge transporting substance and the binder resin. As the binder resin, the binder resin used for the charge generation layer 4 or the binder resin used for the charge transport layer 5 can be used.

The thickness of the photosensitive layer 6 of the single-layer type photosensitive member is 5 μm.
The range is preferably not less than 50 μm and particularly not more than 10 μm and not more than 40 μm. When the thickness of the photosensitive layer is smaller than 5 μm, there is a disadvantage that the charge holding ability is reduced.
On the other hand, when the film thickness is larger than 50 μm, it is difficult to form a uniform film, and there is a disadvantage that productivity is reduced.

The coating solution for the photosensitive layer of the single-layer type photoreceptor is prepared by dissolving or dispersing a charge generating substance, a charge transporting substance and a binder resin in a solvent. As a solvent that can be used, the solvent used for the charge generation layer 4 or the solvent used for the charge transport layer 5 can be used.

According to the present invention, the photosensitive layer 6 of the single-layer type photosensitive member is formed by a dip coating method, but the photosensitive layer 6 can be formed by other general methods such as a spray method, a bead method and a nozzle method. Can be formed.

With respect to the function-separated type and single-layer type photoreceptors, at least one or more electron accepting substances are added to the photosensitive layer 6 in order to improve sensitivity, reduce residual potential, and reduce fatigue during repeated use. It does not matter. Examples of the electron accepting substance that can be added include parabenzoquinone, chloranil, tetrachloro1,2-benzoquinone, hydroquinone, 2,6-dimethylbenzoquinone, methyl 1,
Quinone-based compounds such as 4-benzoquinone, α-naphthoquinone and β-naphthoquinone, 2,4,7-trinitro-
9-fluorenone, 1,3,6,8-tetranitrocarbazole, p-nitrobenzophenone, 2,4,5,7
Nitro compounds such as -tetranitro-9-fluorenone and 2-nitrofluorenone, and tetracyanoethylene, 7,7,8,8-tetracyanoquinodimethane;
And cyano compounds such as 4- (p-nitrobenzoyloxy) -2 ′, 2′-dicyanovinylbenzene and 4- (m-nitrobenzoyloxy) -2 ′, 2′-dicyanovinylbenzene, especially fluorenone-based compounds. Compound,
It is preferable to add a quinone compound and a benzene derivative having an electron-withdrawing substituent such as Cl, CN and NO ₂ .

The photosensitive layer 6 contains an ultraviolet absorber such as benzoic acid, a stilbene compound or a derivative thereof, a triazole compound, an imidazole compound, an oxadiazole compound, a thiazole compound, or a nitrogen-containing compound such as a derivative thereof. And an antioxidant may be contained.

Further, if necessary, a surface protective layer for protecting the surface of the photosensitive layer 6 may be provided on the photosensitive layer 6. For the surface protective layer, a thermoplastic resin or a light or thermosetting resin can be used. The surface protective layer is preferably formed by the dip coating method according to the present invention.
The surface protective layer may contain the above-mentioned ultraviolet ray inhibitor, antioxidant, inorganic material such as metal oxide, organometallic compound, electron-accepting substance, and the like. .

Further, the photosensitive layer 6 and the surface protective layer may be processed, if necessary, by mixing a plasticizer such as a dibasic acid ester, a fatty acid ester, a phosphoric acid ester, a phthalic acid ester and a chlorinated paraffin. The properties and flexibility may be imparted, and the mechanical properties may be improved.

The method for producing an electrophotographic photosensitive member according to the present invention is applied to the formation of a surface protective layer and the like in addition to the undercoat layer 3 and the charge generation layer 4. That is, using a coating liquid containing at least two kinds of solvents and having a viscosity of 20 mPa · s or less, the method is applied when a coating film is formed on a conductive substrate by a dip coating method, and silicone oil is added to the coating liquid. It is characterized by containing. This makes it possible to prevent the liquid from rising during dip coating. The viscosity of the coating liquid is 20 m
When the pressure is higher than Pa · s, the liquid itself does not easily occur due to the low fluidity of the coating liquid.

As the silicone oil which can be contained in the coating liquid in the present invention, generally any oil having an effect of lowering the surface tension can be used. Less or more preferred, especially methyl phenyl silicone oil and dityl phenyl silicone oil.

The viscosity of the silicone oil has a great effect on the effect of preventing the liquid from flowing up. If the viscosity of the silicone oil is too large, the compatibility with the coating liquid is poor, and since the silicone oil is localized on the surface, the rate of consumption with the coating liquid at the time of dip coating increases, and the persistence of the effect deteriorates. . On the other hand, if the viscosity of the silicone oil is too low, the effect of preventing the liquid from flowing out is small, and it must be added in a large amount, which adversely affects the electrostatic characteristics of the electrophotographic photosensitive member. For this reason, the viscosity of the silicone oil is 5 to 50 mPa ·
The range of s is preferred.

When the amount of the silicone oil is small, the effect of preventing liquid drip is small, and when the amount is large, the electrostatic characteristics of the electrophotographic photosensitive member are adversely affected. For this reason, the addition amount of the silicone oil is 1 to 20% by weight based on the solid content of the coating liquid.
Is preferable.

[0079]

The present invention will be described below with reference to examples.
This does not limit the embodiments of the present invention.

Example 1 40 mm in diameter and 340 m in length
The following undercoat layer coating solution was dip-coated on an aluminum drum having a thickness of 1 m and dried at 110 ° C. for 20 minutes to form a 1 μm undercoat layer. The coating solution for the undercoat layer was prepared by dispersing the following components for 10 hours using a paint shaker. [Coating liquid for undercoat layer] Titanium oxide TTO-55A (manufactured by Ishihara Sangyo) 3 parts by weight Polyamide resin CM80000 (manufactured by Toray) 7 parts by weight Methanol 130 parts by weight 1,3-dioxolane 60 parts by weight Methylphenyl silicone oil (viscosity Next, the following coating solution for a charge generation layer was applied onto the undercoat layer by dip coating, and dried at 120 ° C. for 10 minutes to form a 0.3 μm charge generation layer. . The coating solution for the charge generation layer was prepared by dispersing the following components in a sand mill for 3 hours. [Coating solution for charge generation layer] Oxo titanium phthalocyanine 3 parts by weight Polyvinyl butyral resin BM2 (manufactured by Sekisui Chemical Co., Ltd.) 2 parts by weight Cyclohexanone 15 parts by weight 1,2-dimethoxyethane 135 parts by weight Methyl phenyl silicone oil (viscosity 10 mPa · s) 0.1 part by weight Next, the following coating solution for the charge transport layer was applied by dip coating,
After drying at 20 ° C. for 20 minutes, a charge transport layer having a thickness of 30 μm was formed, thereby obtaining a photoreceptor of the present invention. The coating solution for the charge transport layer was prepared by stirring and dissolving the following components. [Coating liquid for charge transport layer] 8 parts by weight of charge transport material having the following structure

[0081]

Embedded image

Polycarbonate resin Z300 (manufactured by Mitsubishi Gas Chemical) 10 parts by weight Silicone oil KF50 (manufactured by Shin-Etsu Chemical) 0.002 parts by weight Dichloromethane 120 parts by weight

Comparative Example 1 The methylphenyl silicone oil (having a viscosity of 1) used in the coating solution for the charge generation layer of Example 1 was used.
A photosensitive member was produced in the same manner as in Example 1 except that 0 mPa · s) was not added.

Comparative Example 2 A photoconductor was prepared in the same manner as in Example 1, except that the coating solution for the charge generation layer in Example 1 was changed to the following. The coating solution for the charge generation layer was prepared by dispersing the following components in a sand mill for 3 hours. [Coating liquid for charge generation layer] Oxo titanium phthalocyanine 3 parts by weight Polyvinyl butyral resin BM2 (manufactured by Sekisui Chemical Co., Ltd.) 2 parts by weight Cyclohexanone 150 parts by weight

Comparative Example 3 A photoconductor was prepared by the same way as that of Example 1 except that the coating solution for charge generating layer of Example 1 was changed to the following. The coating solution for the charge generation layer was prepared by dispersing the following components in a sand mill for 3 hours. [Coating liquid for charge generation layer] Oxo titanium phthalocyanine 3 parts by weight Polyvinyl butyral resin BM2 (manufactured by Sekisui Chemical Co., Ltd.) 2 parts by weight 1,2-dimethoxyethane 150 parts by weight

Example 2 The methylphenyl silicone oil (having a viscosity of 1) used in the coating solution for the charge generation layer of Example 1 was used.
A photoconductor was prepared in the same manner as in Example 1, except that dimethyl silicone oil (viscosity: 10 mPa · s, KF96 manufactured by Shin-Etsu Chemical) was used instead of 0 mPa · s).

Example 3 Dimethyl silicone oil (viscosity of 10 mP) used in the coating solution for the charge generation layer of Example 2
a · s, dimethyl silicone oil (viscosity 2 mPa · s, Shin-Etsu Chemical KF96) instead of Shin-Etsu Chemical KF96
A photoconductor was prepared by the same way as that of Example 2 except that F96) was used.

Example 4 Dimethyl silicone oil (viscosity of 10 mP) used in the coating solution for the charge generation layer of Example 2
a · s, Shin-Etsu Chemical KF96) instead of dimethyl silicone oil (viscosity 5 mPa · s, Shin-Etsu Chemical KF96)
A photoconductor was prepared by the same way as that of Example 2 except that the composition of Example 96) was used.

Example 5 Dimethyl silicone oil (viscosity of 10 mP) used in the coating solution for the charge generation layer of Example 2
a · s, Shin-Etsu Chemical KF96), dimethyl silicone oil (viscosity 50 mPa · s, Shin-Etsu Chemical KF96)
A photoconductor was prepared by the same way as that of Example 2 except that F96) was used.

Example 6 Dimethyl silicone oil (viscosity of 10 mP) used in the coating solution for the charge generation layer of Example 2
A photoconductor was prepared in the same manner as in Example 2, except that dimethyl silicone oil (viscosity: 100 mPa · s, KF96 manufactured by Shin-Etsu Chemical) was used instead of a.s and KF96 manufactured by Shin-Etsu Chemical.

Example 7 Dimethyl silicone oil (viscosity of 10 mP) used in the coating solution for the charge generation layer of Example 2
a.s, a photoreceptor was produced in the same manner as in Example 2, except that the amount of KF96 manufactured by Shin-Etsu Chemical Co., Ltd. was changed to 0.02 parts by weight.

Example 8 Dimethyl silicone oil (viscosity of 10 mP) used in the coating solution for the charge generation layer of Example 2
a.s, a photoreceptor was produced in the same manner as in Example 2 except that the amount of KF96 manufactured by Shin-Etsu Chemical Co., Ltd. was changed to 0.05 part by weight.

Example 9 Dimethyl silicone oil (viscosity of 10 mP) used in the coating solution for the charge generation layer of Example 2
a, s, a photoconductor was prepared in the same manner as in Example 2, except that the amount of KF96 manufactured by Shin-Etsu Chemical Co., Ltd. was changed to 1 part by weight.

Example 10 Dimethyl silicone oil (viscosity of 10 m) used in the coating solution for the charge generation layer of Example 2
A photoconductor was prepared by the same way as that of Example 2 except that the amount of Pa.s, KF96 manufactured by Shin-Etsu Chemical Co., Ltd. was changed to 3 parts by weight.

(Evaluation 1) Examples 1 to 10 and Comparative Example 1
Using the drum evaluation device, the photoreceptor prepared in
By irradiating light of 0 nm, the surface potential is -600 V to 300
The exposure amount that attenuated to V was measured, and this was defined as the sensitivity. In addition, 100 photoreceptors were formed, and the amount of liquid rise in the first and 100th charge generation layers was measured visually. The amount of liquid rise was measured by measuring the length from the lower end of the photoreceptor to the portion where the charge generation layer was not uniform, and expressed as the length. Table 1 shows the results.

[0096]

[Table 1]

Table 1 shows that the addition of silicone oil when the mixed solvent was used in the coating liquid for the charge generation layer reduced the liquid rise. In addition, it can be seen that a liquid that is not a mixed solvent does not cause liquid rise. The viscosity of the silicone oil is suitably in the range of 5 to 50 mPa · s.
If it is larger than this, it can be seen that the stability of the effect of preventing liquid rise during continuous coating is lacking. Also, the addition amount of the silicone oil is appropriately in the range of 1 to 20% by weight. It is understood that the effect of preventing liquid rise is small when the amount is less than this, and the sensitivity is lowered when the amount is larger than this.

Example 11 A photoconductor was prepared by the same way as that of Example 2 except that the coating solution for the charge generating layer of Example 2 was changed to the following. [Coating liquid for charge generation layer] oxotitanium phthalocyanine 3 parts by weight Polyvinyl butyral resin BM2 (manufactured by Sekisui Chemical Co., Ltd.) 2 parts by weight cyclohexanone 3 parts by weight 1,2-dimethoxyethane 147 parts by weight dimethyl silicone oil (viscosity 10 mPa · s, Shin-Etsu Chemical KF96) 0.1 parts by weight

Example 12 A photoconductor was prepared by the same way as that of Example 2 except that the coating solution for the charge generation layer of Example 2 was changed to the following. [Coating liquid for charge generating layer] Oxo titanium phthalocyanine 3 parts by weight Polyvinyl butyral resin BM2 (manufactured by Sekisui Chemical Co., Ltd.) 2 parts by weight Cyclohexanone 7.5 parts by weight 1,2-dimethoxyethane 142.5 parts by weight Dimethyl silicone oil (viscosity 10 mPa · s, Shin-Etsu Chemical KF96) 0.1 parts by weight

Example 13 A photoconductor was prepared by the same way as that of Example 2 except that the coating solution for the charge generation layer of Example 2 was changed to the following. [Coating liquid for charge generation layer] Oxo titanium phthalocyanine 3 parts by weight Polyvinyl butyral resin BM2 (manufactured by Sekisui Chemical Co., Ltd.) 2 parts by weight Cyclohexanone 75 parts by weight 1,2-dimethoxyethane 75 parts by weight Dimethyl silicone oil (viscosity 10 mPa · s, Shin-Etsu Chemical KF96) 0.1 parts by weight

Example 14 A photoconductor was prepared by the same way as that of Example 2 except that the coating solution for charge generating layer of Example 2 was changed to the following. [Coating solution for charge generation layer] Oxo titanium phthalocyanine 3 parts by weight Polyvinyl butyral resin BM2 (manufactured by Sekisui Chemical Co., Ltd.) 2 parts by weight Cyclohexanone 135 parts by weight 1,2-dimethoxyethane 15 parts by weight Dimethyl silicone oil (viscosity 10 mPa · s, Shin-Etsu Chemical KF96) 0.1 parts by weight

(Comparative Example 4) Dimethyl silicone oil (viscosity 10 m) used in the coating solution for the charge generation layer of Example 11
A photoconductor was prepared by the same way as that of Example 11 except that Pa.s, KF96 manufactured by Shin-Etsu Chemical Co., Ltd. was not added.

(Comparative Example 5) Dimethyl silicone oil (viscosity of 10 m) used in the coating solution for the charge generation layer of Example 12
A photoconductor was prepared by the same way as that of Example 12 except that Pa.s, KF96 manufactured by Shin-Etsu Chemical Co., Ltd. was not added.

(Comparative Example 6) Dimethyl silicone oil (viscosity 10 m) used in the coating solution for the charge generation layer of Example 13
A photoconductor was prepared by the same way as that of Example 13 except that Pa.s, KF96 manufactured by Shin-Etsu Chemical Co., Ltd. was not added.

(Comparative Example 7) Dimethyl silicone oil (viscosity of 10 m) used in the coating solution for the charge generation layer of Example 14
A photoconductor was prepared by the same way as that of Example 14 except that Pa.s, KF96 manufactured by Shin-Etsu Chemical Co., Ltd. was not added.

(Evaluation 2) With respect to the photoreceptors produced in Examples 2, 11 to 14 and Comparative Examples 4 to 7, the amount of liquid rise of the charge generation layer was measured visually. In the same manner as in Evaluation 1, the amount of liquid rise was measured by measuring the length from the lower end of the photoreceptor to the portion where the charge generation layer was not uniform, and represented by the length. Table 2 shows the results.

[0107]

[Table 2]

As the solvent for the coating solution for the charge generation layer, a mixed solvent of a ring-type ketone solvent and an ether solvent, particularly a mixed solvent of cyclohexanone and 1,2-dimethoxyethane, which is an ether solvent, is used. When the weight ratio of cyclohexanone / 1,2-dimethoxyethane was 5/9
It can be seen that when the ratio is in the range of 5 to 50/50, the effect at the time of addition is particularly greater than when no silicone oil is added.

Example 15 A photoconductor was prepared by the same way as that of Example 2 except that the coating solution for the charge generating layer of Example 2 was changed to the following. [Coating liquid for charge generation layer] Oxo titanium phthalocyanine 3 parts by weight Polyvinyl butyral resin BM2 (manufactured by Sekisui Chemical) 2 parts by weight cyclohexanone 3 parts by weight Methyl ethyl ketone 147 parts by weight Dimethyl silicone oil (viscosity 10 mPa · s, KF96 manufactured by Shin-Etsu Chemical) 0.1 parts by weight

Example 16 A photoconductor was prepared by the same way as that of Example 2 except that the coating solution for charge generation layer of Example 2 was changed to the following. [Coating solution for charge generation layer] Oxo titanium phthalocyanine 3 parts by weight Polyvinyl butyral resin BM2 (manufactured by Sekisui Chemical Co., Ltd.) 2 parts by weight Cyclohexanone 7.5 parts by weight Methyl ethyl ketone 142.5 parts by weight Dimethyl silicone oil (viscosity 10 mPa · s, Shin-Etsu Chemical KF96) 0.1 parts by weight

Example 17 A photoconductor was prepared by the same way as that of Example 2 except that the coating solution for charge generation layer of Example 2 was changed to the following. [Coating liquid for charge generation layer] Oxo titanium phthalocyanine 3 parts by weight Polyvinyl butyral resin BM2 (manufactured by Sekisui Chemical) 2 parts by weight Cyclohexanone 15 parts by weight Methyl ethyl ketone 135 parts by weight Dimethyl silicone oil (viscosity 10 mPa · s, KF96 manufactured by Shin-Etsu Chemical) 0.1 parts by weight

Example 18 A photoconductor was prepared by the same way as that of Example 2 except that the coating solution for charge generation layer of Example 2 was changed to the following. [Coating liquid for charge generation layer] Oxo titanium phthalocyanine 3 parts by weight Polyvinyl butyral resin BM2 (manufactured by Sekisui Chemical) 2 parts by weight Cyclohexanone 75 parts by weight Methyl ethyl ketone 75 parts by weight Dimethyl silicone oil (viscosity 10 mPa · s, KF96 manufactured by Shin-Etsu Chemical) 0.1 parts by weight

(Example 19) A photoconductor was prepared by the same way as that of Example 2 except that the coating solution for charge generating layer of Example 2 was changed to the following. [Coating solution for charge generation layer] Oxo titanium phthalocyanine 3 parts by weight Polyvinyl butyral resin BM2 (manufactured by Sekisui Chemical) 2 parts by weight Cyclohexanone 135 parts by weight Methyl ethyl ketone 15 parts by weight Dimethyl silicone oil (viscosity 10 mPa · s, KF96 manufactured by Shin-Etsu Chemical) 0.1 parts by weight

(Comparative Example 8) Dimethyl silicone oil (viscosity 10 m) used in the coating solution for the charge generation layer of Example 15
A photoconductor was prepared by the same way as that of Example 15 except that Pa.s, KF96 manufactured by Shin-Etsu Chemical Co., Ltd. was not added.

(Comparative Example 9) Dimethyl silicone oil (viscosity of 10 m) used in the coating solution for the charge generation layer of Example 16
A photoconductor was prepared by the same way as that of Example 16 except that Pa.s, KF96 manufactured by Shin-Etsu Chemical Co., Ltd. was not added.

Comparative Example 10 The dimethyl silicone oil (having a viscosity of 10) used in the coating solution for the charge generation layer of Example 17 was used.
A photoconductor was prepared by the same way as that of Example 17 except that mPa · s, KF96 manufactured by Shin-Etsu Chemical Co., Ltd. was not added.

(Comparative Example 11) Dimethyl silicone oil (viscosity of 10 m) used in the coating solution for the charge generation layer of Example 2
A photoconductor was prepared by the same way as that of Example 18 except that Pa.s, KF96 manufactured by Shin-Etsu Chemical Co., Ltd. was not added.

Comparative Example 12 The dimethyl silicone oil (having a viscosity of 10) used in the coating solution for the charge generation layer of Example 19 was used.
A photoconductor was prepared by the same way as that of Example 19 except that mPa · s, KF96 manufactured by Shin-Etsu Chemical Co., Ltd. was not added.

(Evaluation 3) With respect to the photoreceptors produced in Examples 15 to 19 and Comparative Examples 8 to 12, the amount of liquid rise of the charge generation layer was measured visually. In the same manner as in Evaluation 1, the amount of liquid rise was measured by measuring the length from the lower end of the photoreceptor to the portion where the charge generation layer was not uniform, and represented by the length. Table 3 shows the results.

[0120]

[Table 3]

As the solvent for the coating solution for the charge generation layer, a mixed solvent of a ring-type ketone-based solvent and an aliphatic ketone-based solvent, particularly a mixed solvent of cyclohexanone and an aliphatic ketone-based solvent, methyl ethyl ketone, was used. When the weight ratio of cyclohexanone / dimethoxyethane is from 5/95 to
It can be seen that when the ratio is 50/50, the effect at the time of addition is particularly greater than when no silicone oil is added.

Example 20 A photoconductor was prepared by the same way as that of Example 2 except that the coating solution for charge generation layer of Example 2 was changed to the following. [Coating liquid for charge generation layer] Oxo titanium phthalocyanine 3 parts by weight Polyvinyl butyral resin BM2 (manufactured by Sekisui Chemical) 2 parts by weight cyclohexanone 3 parts by weight Methyl acetate 147 parts by weight Dimethyl silicone oil (viscosity 10 mPa · s, KF96 manufactured by Shin-Etsu Chemical Co., Ltd.) ) 0.1 parts by weight

Example 21 A photoconductor was prepared by the same way as that of Example 2 except that the coating solution for charge generation layer of Example 2 was changed to the following. [Coating liquid for charge generation layer] Oxo titanium phthalocyanine 3 parts by weight Polyvinyl butyral resin BM2 (manufactured by Sekisui Chemical Co., Ltd.) 2 parts by weight Cyclohexanone 7.5 parts by weight Methyl acetate 142.5 parts by weight Dimethyl silicone oil (viscosity 10 mPa · s, Shin-Etsu Chemical KF96) 0.1 parts by weight

Example 22 A photoconductor was prepared by the same way as that of Example 2 except that the coating solution for charge generation layer of Example 2 was changed to the following. [Coating liquid for charge generation layer] Oxo titanium phthalocyanine 3 parts by weight Polyvinyl butyral resin BM2 (manufactured by Sekisui Chemical Co., Ltd.) 2 parts by weight Cyclohexanone 15 parts by weight Methyl acetate 135 parts by weight Dimethyl silicone oil (viscosity 10 mPa · s, KF96 manufactured by Shin-Etsu Chemical Co., Ltd.) ) 0.1 parts by weight

Example 23 A photoconductor was prepared by the same way as that of Example 2 except that the coating solution for charge generating layer of Example 2 was changed to the following. [Coating liquid for charge generation layer] Oxo titanium phthalocyanine 3 parts by weight Polyvinyl butyral resin BM2 (manufactured by Sekisui Chemical) 2 parts by weight cyclohexanone 75 parts by weight Methyl acetate 75 parts by weight Dimethyl silicone oil (viscosity 10 mPa · s, KF96 manufactured by Shin-Etsu Chemical Co., Ltd.) ) 0.1 parts by weight

Example 24 A photoconductor was prepared by the same way as that of Example 2 except that the coating solution for charge generating layer of Example 2 was changed to the following. [Coating liquid for charge generation layer] Oxo titanium phthalocyanine 3 parts by weight Polyvinyl butyral resin BM2 (manufactured by Sekisui Chemical Co., Ltd.) 2 parts by weight Cyclohexanone 135 parts by weight Methyl acetate 15 parts by weight Dimethyl silicone oil (viscosity 10 mPa · s, KF96 manufactured by Shin-Etsu Chemical Co., Ltd.) ) 0.1 parts by weight

Comparative Example 13 The dimethyl silicone oil (having a viscosity of 10) used in the coating solution for the charge generation layer of Example 20 was used.
A photoconductor was prepared by the same way as that of Example 20 except that mPa · s, KF96 manufactured by Shin-Etsu Chemical Co., Ltd. was not added.

Comparative Example 14 The dimethyl silicone oil (having a viscosity of 10) used in the coating solution for the charge generation layer of Example 21 was used.
A photoconductor was prepared by the same way as that of Example 21 except that mPa · s, KF96 manufactured by Shin-Etsu Chemical Co., Ltd. was not added.

Comparative Example 15 The dimethyl silicone oil (having a viscosity of 10) used in the coating solution for the charge generation layer of Example 22 was used.
A photoconductor was prepared by the same way as that of Example 22 except that mPa · s, KF96 manufactured by Shin-Etsu Chemical Co., Ltd. was not added.

Comparative Example 16 The dimethyl silicone oil (having a viscosity of 10) used in the coating solution for the charge generation layer of Example 23 was used.
A photoconductor was prepared by the same way as that of Example 23 except that mPa · s, KF96 manufactured by Shin-Etsu Chemical was not added.

Comparative Example 17 The dimethyl silicone oil (having a viscosity of 10) used in the coating solution for the charge generation layer of Example 24 was used.
A photoconductor was prepared by the same way as that of Example 24 except that mPa · s, KF96 manufactured by Shin-Etsu Chemical Co., Ltd. was not added.

(Evaluation 4) With respect to the photoreceptors prepared in Examples 20 to 24 and Comparative Examples 13 to 17, the amount of liquid rise of the charge generation layer was measured visually. In the same manner as in Evaluation 1, the amount of liquid rise was measured by measuring the length from the lower end of the photoreceptor to the portion where the charge generation layer was not uniform, and represented by the length. Table 4 shows the results.

[0133]

[Table 4]

As a solvent for the coating solution for the charge generation layer, a mixed solvent of a ring-type ketone-based solvent and an ester-based solvent, and particularly when a mixed solvent of cyclohexanone and methyl acetate, which is an ester-based solvent, is used. / When the weight ratio of methyl acetate is in the range of 5/95 to 50/50,
In particular, it can be seen that the effect at the time of addition is greater than when no silicone oil is added.

(Comparative Example 18) Methylphenyl silicone oil (viscosity: 20 mPa
S, a photoreceptor was produced in the same manner as in Example 1 except that KF96 manufactured by Shin-Etsu Chemical Co., Ltd. was not used.

(Evaluation 5) With respect to the photoreceptors prepared in Example 1 and Comparative Example 18, the amount of liquid rise of the undercoat layer was visually observed. The amount of liquid rise was measured by measuring the length from the lower end of the photoreceptor to the portion where the undercoat layer was not uniform, and expressed as the length. Table 5 shows the results.

[0137]

[Table 5]

The solvent of the undercoat layer coating liquid is a mixed solvent of dioxolane and an alcohol solvent, particularly a mixed solvent of dioxolane and methanol, and the undercoat layer coating liquid is an alcohol-soluble nylon. It can be seen that even when a resin is contained, the addition of silicone oil to the coating liquid has the same effect of preventing the liquid from flowing out as in the case of the charge generation layer.

The following dispersions were prepared as reference examples. The following components were dispersed in a ball mill for 48 hours to prepare a dispersion.

Perylene pigment 1 part by weight Polycarbonate resin (Z type) 9 parts by weight Cyclohexanone 9 parts by weight Tetrahydrofuran 89 parts by weight

The solid content of the above dispersion was adjusted so as to maintain the solvent ratio (cyclohexanone / tetrahydrofuran = 1/9) to prepare liquids having viscosities of 5, 10, 20, and 50 mPa · s. Then, the liquid was applied to the substrate by dip coating, and the amount of liquid rise was measured. Table 6 shows the results.

[0142]

[Table 6]

From Table 6, it can be seen that liquid rise occurs only when the viscosity of the coating liquid is relatively small, that is, when the viscosity is about 20 mPa · s or less. Regarding the viscosity of the coating liquid used in this example and the comparative example, the coating liquid for the charge generation layer was 5 m
Pa · s or less, and the coating liquid for the undercoat layer is 5 to 10 mP.
a · s, and had a relatively low viscosity.

Further, the present invention is not limited to the method for producing an electrophotographic photosensitive member.
The image forming apparatus 21 equipped with the photoconductor 1 also belongs to the scope of the present invention.

[0145]

As described above, according to the present invention, a coating solution for a photosensitive layer formed by dip coating a coating film using at least two kinds of solvents has a viscosity of 20 mPa · s or less and a silicone oil. , It is possible to prevent a liquid rise which is an abnormality of a coating film when producing a photosensitive layer.

Further, according to the present invention, the silicone oil is preferably a methylphenyl silicone oil or a ditylphenyl silicone oil.

Further, according to the present invention, since the coating liquid is a coating liquid for the charge generation layer or the undercoat layer, it is possible to prevent the liquid from flowing when these layers are formed.

According to the present invention, since the viscosity of the silicone oil is in the range of 5 to 50 mPa · s, it is possible to prevent the liquid from flowing up.

Further, according to the present invention, the addition amount of the silicone oil is in the range of 1 to 20% by weight with respect to the solid content of the coating liquid, so that the rise of the liquid can be effectively prevented.

Further, according to the present invention, the solvent of the coating liquid for the charge generation layer is a mixed solvent of a ring-type ketone solvent and an aliphatic ketone solvent, or a mixed solvent of a ring-type ketone solvent and an ester solvent. Alternatively, it is preferably a mixed solvent of a finger-type ketone solvent and an ether solvent.

Further, according to the present invention, the mixed solvent of the finger ring ketone solvent and the aliphatic ketone solvent is a mixed solvent of cyclohexanone and an aliphatic ketone solvent, and a mixed solvent of cyclohexanone and an aliphatic ketone solvent. Weight ratio of cyclohexanone / aliphatic ketone solvent is 5/95 to 5
It is preferably in the range of 0/50.

According to the present invention, the mixed solvent of the finger ring ketone solvent and the ester solvent is a mixed solvent of cyclohexanone and the ester solvent, and the weight ratio of the cyclohexanone and the ester solvent is cyclohexanone. The ratio is preferably in the range of 5/95 to 50/50 in the ratio of / ester solvent.

According to the present invention, the mixed solvent of the finger ring ketone solvent and the ether solvent is a mixed solvent of cyclohexanone and an ether solvent, and the weight ratio of cyclohexanone and the ether solvent is cyclohexanone / ether. The ether solvent is preferably in the range of 5/95 to 50/50.

According to the invention, the solvent for the undercoat layer coating liquid is a mixed solvent of dioxolane and an alcohol solvent, and the undercoat layer coating liquid contains an alcohol-soluble nylon resin. Is preferred.

Further, according to the present invention, the mixed solvent of dioxolane and the alcohol solvent is preferably a mixed solvent of dioxolane and methanol.

According to the present invention, in an electrophotographic photosensitive member having a photosensitive layer on a conductive substrate, at least one layer formed on the conductive substrate is formed by the method of the first present invention. , A larger area can be used as the effective image area.

According to the present invention, in an electrophotographic photoreceptor having at least a charge generation layer and a charge transport layer on a conductive substrate, at least the charge generation layer is formed by the method of the fourth invention. A larger area can be used as the effective image area.

According to the present invention, in an electrophotographic photoreceptor having at least an undercoat layer and a photosensitive layer on a conductive substrate, at least the undercoat layer is formed by the method of the fifth present invention. A large area can be used as an effective image area.

Further, according to the present invention, the electrophotographic apparatus is the first type.
Since the electrophotographic photosensitive member of the present invention of Nos. 6 to 18 is provided, good image quality with few image defects can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a dip coating apparatus 10 used in a method for manufacturing an electrophotographic photosensitive member according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view of a photoreceptor 1 manufactured by the method for manufacturing a photoreceptor.

FIG. 3 is a view showing an image forming apparatus 21 on which the photoconductor 1 is mounted.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 electrophotographic photoreceptor 2 conductive substrate 3 undercoat layer 4 charge generation layer 5 charge transport layer 6 photosensitive layer 10 dip coating device 11 coating liquid tank 12 coating liquid 13 lifting device 14 arm 15 motor 21 image forming device 22 charging device 23 Exposure device 24 Developing device 25 Recording paper 26 Transfer device 27 Fixing device 28 Cleaning device 29 Static eliminator

Claims (19)

[Claims] 1. A method for producing an electrophotographic photosensitive member, wherein a coating film is formed on a conductive substrate by a dip coating method using a coating liquid containing at least two kinds of solvents, wherein the coating liquid is silicone. A method for producing an electrophotographic photoreceptor, comprising an oil, wherein the viscosity of the coating liquid is 20 mPa · s or less. 2. The method according to claim 1, wherein said silicone oil is methylphenyl silicone oil. 3. The method according to claim 1, wherein the silicone oil is dimethyl silicone oil. 4. The method according to claim 1, wherein the coating liquid is a coating liquid for a charge generation layer. 5. The method according to claim 1, wherein the coating liquid is a coating liquid for an undercoat layer. 6. The silicone oil has a viscosity of 5 to 50.
2. The method for producing an electrophotographic photosensitive member according to claim 1, wherein the range is mPa · s. 7. The method according to claim 1, wherein the amount of the silicone oil added is in the range of 1 to 20% by weight based on the solid content of the coating solution. 8. The method for producing an electrophotographic photoreceptor according to claim 4, wherein the solvent of the coating solution for the charge generation layer is a mixed solvent of a ring-type ketone-based solvent and an aliphatic ketone-based solvent. . 9. The method for producing an electrophotographic photoreceptor according to claim 4, wherein the solvent of the coating solution for the charge generation layer is a mixed solvent of a ring-type ketone solvent and an ester solvent. 10. The method for producing an electrophotographic photoreceptor according to claim 4, wherein the solvent of the coating solution for the charge generation layer is a mixed solvent of a ring-type ketone solvent and an ether solvent. 11. The mixed solvent of a finger ring ketone solvent and an aliphatic ketone solvent is a mixed solvent of cyclohexanone and an aliphatic ketone solvent, and the weight ratio of cyclohexanone to the aliphatic ketone solvent is cyclohexanone. /
The method for producing an electrophotographic photoreceptor according to claim 8, wherein the aliphatic ketone-based solvent is in a range of 5/95 to 50/50. 12. The mixed solvent of a finger ring ketone solvent and an ester solvent is a mixed solvent of cyclohexanone and an ester solvent, and the weight ratio of cyclohexanone and the ester solvent is 5% by weight of a cyclohexanone / ester solvent. The method for producing an electrophotographic photosensitive member according to claim 9, wherein the ratio is in the range of / 95 to 50/50. 13. The mixed solvent of a finger ring type ketone solvent and an ether solvent is a mixed solvent of cyclohexanone and an ether solvent, and the weight ratio of cyclohexanone and the ether solvent is 5 / (cyclohexanone / ether solvent). 11. The method according to claim 10, wherein the ratio is in the range of 95 to 50/50. 14. The undercoat layer coating solution is a mixed solvent of dioxolane and an alcohol solvent, and the undercoat layer coating solution contains an alcohol-soluble nylon resin. Item 6. The method for producing an electrophotographic photosensitive member according to Item 5. 15. The method according to claim 14, wherein the mixed solvent of dioxolane and alcohol solvent is a mixed solvent of dioxolane and methanol. 16. An electrophotographic photoreceptor having a photosensitive layer on a conductive substrate, wherein at least one layer formed on the conductive substrate is a layer formed by the method according to claim 1. An electrophotographic photosensitive member characterized by the following. 17. An electrophotographic photosensitive member having at least a charge generation layer and a charge transport layer on a conductive substrate, wherein at least the charge generation layer is a layer formed by the method according to claim 4. Electrophotographic photoreceptor. 18. An electrophotographic photoreceptor having at least an undercoat layer and a photosensitive layer on a conductive substrate, wherein at least the undercoat layer is a layer formed by the method according to claim 5. Electrophotographic photoreceptor. 19. An electrostatic latent image is formed by charging the surface of an electrophotographic photoreceptor to a predetermined potential and exposing the same, and the formed electrostatic latent image is developed with a developer, transferred to a recording material and fixed. An image forming apparatus for forming an image by an electrophotographic method, comprising the electrophotographic photosensitive member according to any one of claims 16 to 18 as the electrophotographic photosensitive member.